| 1 | /* $Id: tritemp.h,v 1.1 2000-02-29 00:48:40 sandervl Exp $ */
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| 2 |
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| 3 | /*
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| 4 | * Mesa 3-D graphics library
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| 5 | * Version: 3.1
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| 6 | *
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| 7 | * Copyright (C) 1999 Brian Paul All Rights Reserved.
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| 8 | *
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| 9 | * Permission is hereby granted, free of charge, to any person obtaining a
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| 10 | * copy of this software and associated documentation files (the "Software"),
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| 11 | * to deal in the Software without restriction, including without limitation
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| 12 | * the rights to use, copy, modify, merge, publish, distribute, sublicense,
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| 13 | * and/or sell copies of the Software, and to permit persons to whom the
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| 14 | * Software is furnished to do so, subject to the following conditions:
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| 15 | *
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| 16 | * The above copyright notice and this permission notice shall be included
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| 17 | * in all copies or substantial portions of the Software.
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| 18 | *
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| 19 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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| 20 | * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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| 21 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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| 22 | * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
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| 23 | * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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| 24 | * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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| 25 | */
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| 26 |
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| 27 |
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| 28 | /*
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| 29 | * Triangle Rasterizer Template
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| 30 | *
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| 31 | * This file is #include'd to generate custom triangle rasterizers.
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| 32 | *
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| 33 | * The following macros may be defined to indicate what auxillary information
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| 34 | * must be interplated across the triangle:
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| 35 | * INTERP_Z - if defined, interpolate Z values
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| 36 | * INTERP_RGB - if defined, interpolate RGB values
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| 37 | * INTERP_SPEC - if defined, interpolate specular RGB values
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| 38 | * INTERP_ALPHA - if defined, interpolate Alpha values
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| 39 | * INTERP_INDEX - if defined, interpolate color index values
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| 40 | * INTERP_INT_ST - if defined, interpolate integer ST texcoords
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| 41 | * (fast, simple 2-D texture mapping)
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| 42 | * INTERP_STUV - if defined, interpolate set 0 float STRQ texcoords
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| 43 | * NOTE: OpenGL STRQ = Mesa STUV (R was taken for red)
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| 44 | * INTERP_STUV1 - if defined, interpolate set 1 float STRQ texcoords
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| 45 | *
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| 46 | * When one can directly address pixels in the color buffer the following
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| 47 | * macros can be defined and used to compute pixel addresses during
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| 48 | * rasterization (see pRow):
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| 49 | * PIXEL_TYPE - the datatype of a pixel (GLubyte, GLushort, GLuint)
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| 50 | * BYTES_PER_ROW - number of bytes per row in the color buffer
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| 51 | * PIXEL_ADDRESS(X,Y) - returns the address of pixel at (X,Y) where
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| 52 | * Y==0 at bottom of screen and increases upward.
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| 53 | *
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| 54 | * Optionally, one may provide one-time setup code per triangle:
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| 55 | * SETUP_CODE - code which is to be executed once per triangle
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| 56 | *
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| 57 | * The following macro MUST be defined:
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| 58 | * INNER_LOOP(LEFT,RIGHT,Y) - code to write a span of pixels.
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| 59 | * Something like:
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| 60 | *
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| 61 | * for (x=LEFT; x<RIGHT;x++) {
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| 62 | * put_pixel(x,Y);
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| 63 | * // increment fixed point interpolants
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| 64 | * }
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| 65 | *
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| 66 | * This code was designed for the origin to be in the lower-left corner.
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| 67 | *
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| 68 | * Inspired by triangle rasterizer code written by Allen Akin. Thanks Allen!
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| 69 | */
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| 70 |
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| 71 |
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| 72 | /*void triangle( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint pv )*/
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| 73 | {
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| 74 | typedef struct {
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| 75 | GLint v0, v1; /* Y(v0) < Y(v1) */
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| 76 | GLfloat dx; /* X(v1) - X(v0) */
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| 77 | GLfloat dy; /* Y(v1) - Y(v0) */
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| 78 | GLfixed fdxdy; /* dx/dy in fixed-point */
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| 79 | GLfixed fsx; /* first sample point x coord */
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| 80 | GLfixed fsy;
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| 81 | GLfloat adjy; /* adjust from v[0]->fy to fsy, scaled */
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| 82 | GLint lines; /* number of lines to be sampled on this edge */
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| 83 | GLfixed fx0; /* fixed pt X of lower endpoint */
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| 84 | } EdgeT;
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| 85 |
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| 86 | struct vertex_buffer *VB = ctx->VB;
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| 87 | EdgeT eMaj, eTop, eBot;
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| 88 | GLfloat oneOverArea;
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| 89 | int vMin, vMid, vMax; /* vertex indexes: Y(vMin)<=Y(vMid)<=Y(vMax) */
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| 90 | float bf = ctx->backface_sign;
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| 91 |
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| 92 | /* find the order of the 3 vertices along the Y axis */
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| 93 | {
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| 94 | GLfloat y0 = VB->Win.data[v0][1];
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| 95 | GLfloat y1 = VB->Win.data[v1][1];
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| 96 | GLfloat y2 = VB->Win.data[v2][1];
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| 97 |
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| 98 | if (y0<=y1) {
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| 99 | if (y1<=y2) {
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| 100 | vMin = v0; vMid = v1; vMax = v2; /* y0<=y1<=y2 */
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| 101 | }
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| 102 | else if (y2<=y0) {
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| 103 | vMin = v2; vMid = v0; vMax = v1; /* y2<=y0<=y1 */
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| 104 | }
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| 105 | else {
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| 106 | vMin = v0; vMid = v2; vMax = v1; bf = -bf; /* y0<=y2<=y1 */
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| 107 | }
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| 108 | }
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| 109 | else {
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| 110 | if (y0<=y2) {
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| 111 | vMin = v1; vMid = v0; vMax = v2; bf = -bf; /* y1<=y0<=y2 */
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| 112 | }
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| 113 | else if (y2<=y1) {
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| 114 | vMin = v2; vMid = v1; vMax = v0; bf = -bf; /* y2<=y1<=y0 */
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| 115 | }
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| 116 | else {
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| 117 | vMin = v1; vMid = v2; vMax = v0; /* y1<=y2<=y0 */
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| 118 | }
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| 119 | }
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| 120 | }
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| 121 |
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| 122 | /* vertex/edge relationship */
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| 123 | eMaj.v0 = vMin; eMaj.v1 = vMax; /*TODO: .v1's not needed */
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| 124 | eTop.v0 = vMid; eTop.v1 = vMax;
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| 125 | eBot.v0 = vMin; eBot.v1 = vMid;
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| 126 |
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| 127 | /* compute deltas for each edge: vertex[v1] - vertex[v0] */
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| 128 | eMaj.dx = VB->Win.data[vMax][0] - VB->Win.data[vMin][0];
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| 129 | eMaj.dy = VB->Win.data[vMax][1] - VB->Win.data[vMin][1];
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| 130 | eTop.dx = VB->Win.data[vMax][0] - VB->Win.data[vMid][0];
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| 131 | eTop.dy = VB->Win.data[vMax][1] - VB->Win.data[vMid][1];
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| 132 | eBot.dx = VB->Win.data[vMid][0] - VB->Win.data[vMin][0];
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| 133 | eBot.dy = VB->Win.data[vMid][1] - VB->Win.data[vMin][1];
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| 134 |
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| 135 | /* compute oneOverArea */
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| 136 | {
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| 137 | GLfloat area = eMaj.dx * eBot.dy - eBot.dx * eMaj.dy;
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| 138 |
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| 139 | /* Do backface culling */
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| 140 | if (
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| 141 | area * bf < 0 ||
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| 142 | area * area < .0025
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| 143 | )
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| 144 | return;
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| 145 |
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| 146 |
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| 147 | oneOverArea = 1.0F / area;
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| 148 | }
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| 149 |
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| 150 | /* Edge setup. For a triangle strip these could be reused... */
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| 151 | {
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| 152 | /* fixed point Y coordinates */
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| 153 | GLfixed vMin_fx = FloatToFixed(VB->Win.data[vMin][0] + 0.5F);
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| 154 | GLfixed vMin_fy = FloatToFixed(VB->Win.data[vMin][1] - 0.5F);
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| 155 | GLfixed vMid_fx = FloatToFixed(VB->Win.data[vMid][0] + 0.5F);
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| 156 | GLfixed vMid_fy = FloatToFixed(VB->Win.data[vMid][1] - 0.5F);
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| 157 | GLfixed vMax_fy = FloatToFixed(VB->Win.data[vMax][1] - 0.5F);
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| 158 |
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| 159 | eMaj.fsy = FixedCeil(vMin_fy);
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| 160 | eMaj.lines = FixedToInt(vMax_fy + FIXED_ONE - FIXED_EPSILON - eMaj.fsy);
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| 161 | if (eMaj.lines > 0) {
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| 162 | GLfloat dxdy = eMaj.dx / eMaj.dy;
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| 163 | eMaj.fdxdy = SignedFloatToFixed(dxdy);
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| 164 | eMaj.adjy = (GLfloat) (eMaj.fsy - vMin_fy); /* SCALED! */
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| 165 | eMaj.fx0 = vMin_fx;
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| 166 | eMaj.fsx = eMaj.fx0 + (GLfixed) (eMaj.adjy * dxdy);
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| 167 | }
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| 168 | else {
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| 169 | return; /*CULLED*/
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| 170 | }
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| 171 |
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| 172 | eTop.fsy = FixedCeil(vMid_fy);
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| 173 | eTop.lines = FixedToInt(vMax_fy + FIXED_ONE - FIXED_EPSILON - eTop.fsy);
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| 174 | if (eTop.lines > 0) {
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| 175 | GLfloat dxdy = eTop.dx / eTop.dy;
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| 176 | eTop.fdxdy = SignedFloatToFixed(dxdy);
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| 177 | eTop.adjy = (GLfloat) (eTop.fsy - vMid_fy); /* SCALED! */
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| 178 | eTop.fx0 = vMid_fx;
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| 179 | eTop.fsx = eTop.fx0 + (GLfixed) (eTop.adjy * dxdy);
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| 180 | }
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| 181 |
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| 182 | eBot.fsy = FixedCeil(vMin_fy);
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| 183 | eBot.lines = FixedToInt(vMid_fy + FIXED_ONE - FIXED_EPSILON - eBot.fsy);
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| 184 | if (eBot.lines > 0) {
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| 185 | GLfloat dxdy = eBot.dx / eBot.dy;
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| 186 | eBot.fdxdy = SignedFloatToFixed(dxdy);
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| 187 | eBot.adjy = (GLfloat) (eBot.fsy - vMin_fy); /* SCALED! */
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| 188 | eBot.fx0 = vMin_fx;
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| 189 | eBot.fsx = eBot.fx0 + (GLfixed) (eBot.adjy * dxdy);
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| 190 | }
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| 191 | }
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| 192 |
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| 193 | /*
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| 194 | * Conceptually, we view a triangle as two subtriangles
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| 195 | * separated by a perfectly horizontal line. The edge that is
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| 196 | * intersected by this line is one with maximal absolute dy; we
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| 197 | * call it a ``major'' edge. The other two edges are the
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| 198 | * ``top'' edge (for the upper subtriangle) and the ``bottom''
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| 199 | * edge (for the lower subtriangle). If either of these two
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| 200 | * edges is horizontal or very close to horizontal, the
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| 201 | * corresponding subtriangle might cover zero sample points;
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| 202 | * we take care to handle such cases, for performance as well
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| 203 | * as correctness.
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| 204 | *
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| 205 | * By stepping rasterization parameters along the major edge,
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| 206 | * we can avoid recomputing them at the discontinuity where
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| 207 | * the top and bottom edges meet. However, this forces us to
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| 208 | * be able to scan both left-to-right and right-to-left.
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| 209 | * Also, we must determine whether the major edge is at the
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| 210 | * left or right side of the triangle. We do this by
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| 211 | * computing the magnitude of the cross-product of the major
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| 212 | * and top edges. Since this magnitude depends on the sine of
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| 213 | * the angle between the two edges, its sign tells us whether
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| 214 | * we turn to the left or to the right when travelling along
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| 215 | * the major edge to the top edge, and from this we infer
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| 216 | * whether the major edge is on the left or the right.
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| 217 | *
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| 218 | * Serendipitously, this cross-product magnitude is also a
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| 219 | * value we need to compute the iteration parameter
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| 220 | * derivatives for the triangle, and it can be used to perform
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| 221 | * backface culling because its sign tells us whether the
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| 222 | * triangle is clockwise or counterclockwise. In this code we
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| 223 | * refer to it as ``area'' because it's also proportional to
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| 224 | * the pixel area of the triangle.
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| 225 | */
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| 226 |
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| 227 | {
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| 228 | GLint ltor; /* true if scanning left-to-right */
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| 229 | #if INTERP_Z
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| 230 | GLfloat dzdx, dzdy; GLfixed fdzdx;
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| 231 | #endif
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| 232 | #if INTERP_RGB
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| 233 | GLfloat drdx, drdy; GLfixed fdrdx;
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| 234 | GLfloat dgdx, dgdy; GLfixed fdgdx;
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| 235 | GLfloat dbdx, dbdy; GLfixed fdbdx;
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| 236 | #endif
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| 237 | #if INTERP_SPEC
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| 238 | GLfloat dsrdx, dsrdy; GLfixed fdsrdx;
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| 239 | GLfloat dsgdx, dsgdy; GLfixed fdsgdx;
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| 240 | GLfloat dsbdx, dsbdy; GLfixed fdsbdx;
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| 241 | #endif
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| 242 | #if INTERP_ALPHA
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| 243 | GLfloat dadx, dady; GLfixed fdadx;
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| 244 | #endif
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| 245 | #if INTERP_INDEX
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| 246 | GLfloat didx, didy; GLfixed fdidx;
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| 247 | #endif
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| 248 | #if INTERP_INT_ST
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| 249 | GLfloat dsdx, dsdy; GLfixed fdsdx;
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| 250 | GLfloat dtdx, dtdy; GLfixed fdtdx;
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| 251 | #endif
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| 252 | #if INTERP_STUV
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| 253 | GLfloat dsdx, dsdy;
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| 254 | GLfloat dtdx, dtdy;
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| 255 | GLfloat dudx, dudy;
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| 256 | GLfloat dvdx, dvdy;
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| 257 | #endif
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| 258 | #if INTERP_STUV1
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| 259 | GLfloat ds1dx, ds1dy;
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| 260 | GLfloat dt1dx, dt1dy;
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| 261 | GLfloat du1dx, du1dy;
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| 262 | GLfloat dv1dx, dv1dy;
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| 263 | #endif
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| 264 |
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| 265 | /*
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| 266 | * Execute user-supplied setup code
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| 267 | */
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| 268 | #ifdef SETUP_CODE
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| 269 | SETUP_CODE
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| 270 | #endif
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| 271 |
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| 272 | ltor = (oneOverArea < 0.0F);
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| 273 |
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| 274 | /* compute d?/dx and d?/dy derivatives */
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| 275 | #if INTERP_Z
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| 276 | {
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| 277 | GLfloat eMaj_dz, eBot_dz;
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| 278 | eMaj_dz = VB->Win.data[vMax][2] - VB->Win.data[vMin][2];
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| 279 | eBot_dz = VB->Win.data[vMid][2] - VB->Win.data[vMin][2];
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| 280 | dzdx = oneOverArea * (eMaj_dz * eBot.dy - eMaj.dy * eBot_dz);
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| 281 | if (dzdx>DEPTH_SCALE || dzdx<-DEPTH_SCALE) {
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| 282 | /* probably a sliver triangle */
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| 283 | dzdx = 0.0;
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| 284 | dzdy = 0.0;
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| 285 | }
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| 286 | else {
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| 287 | dzdy = oneOverArea * (eMaj.dx * eBot_dz - eMaj_dz * eBot.dx);
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| 288 | }
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| 289 | #if DEPTH_BITS==16
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| 290 | fdzdx = SignedFloatToFixed(dzdx);
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| 291 | #else
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| 292 | fdzdx = (GLint) dzdx;
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| 293 | #endif
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| 294 | }
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| 295 | #endif
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| 296 | #if INTERP_RGB
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| 297 | {
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| 298 | GLfloat eMaj_dr, eBot_dr;
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| 299 | eMaj_dr = (GLint) VB->ColorPtr->data[vMax][0] - (GLint) VB->ColorPtr->data[vMin][0];
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| 300 | eBot_dr = (GLint) VB->ColorPtr->data[vMid][0] - (GLint) VB->ColorPtr->data[vMin][0];
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| 301 | drdx = oneOverArea * (eMaj_dr * eBot.dy - eMaj.dy * eBot_dr);
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| 302 | fdrdx = SignedFloatToFixed(drdx);
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| 303 | drdy = oneOverArea * (eMaj.dx * eBot_dr - eMaj_dr * eBot.dx);
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| 304 | }
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| 305 | {
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| 306 | GLfloat eMaj_dg, eBot_dg;
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| 307 | eMaj_dg = (GLint) VB->ColorPtr->data[vMax][1] - (GLint) VB->ColorPtr->data[vMin][1];
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| 308 | eBot_dg = (GLint) VB->ColorPtr->data[vMid][1] - (GLint) VB->ColorPtr->data[vMin][1];
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| 309 | dgdx = oneOverArea * (eMaj_dg * eBot.dy - eMaj.dy * eBot_dg);
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| 310 | fdgdx = SignedFloatToFixed(dgdx);
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| 311 | dgdy = oneOverArea * (eMaj.dx * eBot_dg - eMaj_dg * eBot.dx);
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| 312 | }
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| 313 | {
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| 314 | GLfloat eMaj_db, eBot_db;
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| 315 | eMaj_db = (GLint) VB->ColorPtr->data[vMax][2] - (GLint) VB->ColorPtr->data[vMin][2];
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| 316 | eBot_db = (GLint) VB->ColorPtr->data[vMid][2] - (GLint) VB->ColorPtr->data[vMin][2];
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| 317 | dbdx = oneOverArea * (eMaj_db * eBot.dy - eMaj.dy * eBot_db);
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| 318 | fdbdx = SignedFloatToFixed(dbdx);
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| 319 | dbdy = oneOverArea * (eMaj.dx * eBot_db - eMaj_db * eBot.dx);
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| 320 | }
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| 321 | #endif
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| 322 | #if INTERP_SPEC
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| 323 | {
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| 324 | GLfloat eMaj_dsr, eBot_dsr;
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| 325 | eMaj_dsr = (GLint) VB->Specular[vMax][0] - (GLint) VB->Specular[vMin][0];
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| 326 | eBot_dsr = (GLint) VB->Specular[vMid][0] - (GLint) VB->Specular[vMin][0];
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| 327 | dsrdx = oneOverArea * (eMaj_dsr * eBot.dy - eMaj.dy * eBot_dsr);
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| 328 | fdsrdx = SignedFloatToFixed(dsrdx);
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| 329 | dsrdy = oneOverArea * (eMaj.dx * eBot_dsr - eMaj_dsr * eBot.dx);
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| 330 | }
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| 331 | {
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| 332 | GLfloat eMaj_dsg, eBot_dsg;
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| 333 | eMaj_dsg = (GLint) VB->Specular[vMax][1] - (GLint) VB->Specular[vMin][1];
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| 334 | eBot_dsg = (GLint) VB->Specular[vMid][1] - (GLint) VB->Specular[vMin][1];
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| 335 | dsgdx = oneOverArea * (eMaj_dsg * eBot.dy - eMaj.dy * eBot_dsg);
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| 336 | fdsgdx = SignedFloatToFixed(dsgdx);
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| 337 | dsgdy = oneOverArea * (eMaj.dx * eBot_dsg - eMaj_dsg * eBot.dx);
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| 338 | }
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| 339 | {
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| 340 | GLfloat eMaj_dsb, eBot_dsb;
|
|---|
| 341 | eMaj_dsb = (GLint) VB->Specular[vMax][2] - (GLint) VB->Specular[vMin][2];
|
|---|
| 342 | eBot_dsb = (GLint) VB->Specular[vMid][2] - (GLint) VB->Specular[vMin][2];
|
|---|
| 343 | dsbdx = oneOverArea * (eMaj_dsb * eBot.dy - eMaj.dy * eBot_dsb);
|
|---|
| 344 | fdsbdx = SignedFloatToFixed(dsbdx);
|
|---|
| 345 | dsbdy = oneOverArea * (eMaj.dx * eBot_dsb - eMaj_dsb * eBot.dx);
|
|---|
| 346 | }
|
|---|
| 347 | #endif
|
|---|
| 348 | #if INTERP_ALPHA
|
|---|
| 349 | {
|
|---|
| 350 | GLfloat eMaj_da, eBot_da;
|
|---|
| 351 | eMaj_da = (GLint) VB->ColorPtr->data[vMax][3] - (GLint) VB->ColorPtr->data[vMin][3];
|
|---|
| 352 | eBot_da = (GLint) VB->ColorPtr->data[vMid][3] - (GLint) VB->ColorPtr->data[vMin][3];
|
|---|
| 353 | dadx = oneOverArea * (eMaj_da * eBot.dy - eMaj.dy * eBot_da);
|
|---|
| 354 | fdadx = SignedFloatToFixed(dadx);
|
|---|
| 355 | dady = oneOverArea * (eMaj.dx * eBot_da - eMaj_da * eBot.dx);
|
|---|
| 356 | }
|
|---|
| 357 | #endif
|
|---|
| 358 | #if INTERP_INDEX
|
|---|
| 359 | {
|
|---|
| 360 | GLfloat eMaj_di, eBot_di;
|
|---|
| 361 | eMaj_di = (GLint) VB->IndexPtr->data[vMax] - (GLint) VB->IndexPtr->data[vMin];
|
|---|
| 362 | eBot_di = (GLint) VB->IndexPtr->data[vMid] - (GLint) VB->IndexPtr->data[vMin];
|
|---|
| 363 | didx = oneOverArea * (eMaj_di * eBot.dy - eMaj.dy * eBot_di);
|
|---|
| 364 | fdidx = SignedFloatToFixed(didx);
|
|---|
| 365 | didy = oneOverArea * (eMaj.dx * eBot_di - eMaj_di * eBot.dx);
|
|---|
| 366 | }
|
|---|
| 367 | #endif
|
|---|
| 368 | #if INTERP_INT_ST
|
|---|
| 369 | {
|
|---|
| 370 | GLfloat eMaj_ds, eBot_ds;
|
|---|
| 371 | eMaj_ds = (VB->TexCoordPtr[0]->data[vMax][0] - VB->TexCoordPtr[0]->data[vMin][0]) * S_SCALE;
|
|---|
| 372 | eBot_ds = (VB->TexCoordPtr[0]->data[vMid][0] - VB->TexCoordPtr[0]->data[vMin][0]) * S_SCALE;
|
|---|
| 373 | dsdx = oneOverArea * (eMaj_ds * eBot.dy - eMaj.dy * eBot_ds);
|
|---|
| 374 | fdsdx = SignedFloatToFixed(dsdx);
|
|---|
| 375 | dsdy = oneOverArea * (eMaj.dx * eBot_ds - eMaj_ds * eBot.dx);
|
|---|
| 376 | }
|
|---|
| 377 | if (VB->TexCoordPtr[0]->size > 1)
|
|---|
| 378 | {
|
|---|
| 379 | GLfloat eMaj_dt, eBot_dt;
|
|---|
| 380 | eMaj_dt = (VB->TexCoordPtr[0]->data[vMax][1] - VB->TexCoordPtr[0]->data[vMin][1]) * T_SCALE;
|
|---|
| 381 | eBot_dt = (VB->TexCoordPtr[0]->data[vMid][1] - VB->TexCoordPtr[0]->data[vMin][1]) * T_SCALE;
|
|---|
| 382 | dtdx = oneOverArea * (eMaj_dt * eBot.dy - eMaj.dy * eBot_dt);
|
|---|
| 383 | fdtdx = SignedFloatToFixed(dtdx);
|
|---|
| 384 | dtdy = oneOverArea * (eMaj.dx * eBot_dt - eMaj_dt * eBot.dx);
|
|---|
| 385 | } else {
|
|---|
| 386 | dtdx = 0;
|
|---|
| 387 | fdtdx = SignedFloatToFixed(dtdx);
|
|---|
| 388 | dtdy = 0;
|
|---|
| 389 | }
|
|---|
| 390 |
|
|---|
| 391 | #endif
|
|---|
| 392 | #if INTERP_STUV
|
|---|
| 393 | {
|
|---|
| 394 | GLfloat wMax = VB->Win.data[vMax][3];
|
|---|
| 395 | GLfloat wMin = VB->Win.data[vMin][3];
|
|---|
| 396 | GLfloat wMid = VB->Win.data[vMid][3];
|
|---|
| 397 | GLfloat eMaj_ds, eBot_ds;
|
|---|
| 398 | GLfloat eMaj_dt, eBot_dt;
|
|---|
| 399 | GLfloat eMaj_du, eBot_du;
|
|---|
| 400 | GLfloat eMaj_dv, eBot_dv;
|
|---|
| 401 |
|
|---|
| 402 | eMaj_ds = VB->TexCoordPtr[0]->data[vMax][0]*wMax - VB->TexCoordPtr[0]->data[vMin][0]*wMin;
|
|---|
| 403 | eBot_ds = VB->TexCoordPtr[0]->data[vMid][0]*wMid - VB->TexCoordPtr[0]->data[vMin][0]*wMin;
|
|---|
| 404 | dsdx = oneOverArea * (eMaj_ds * eBot.dy - eMaj.dy * eBot_ds);
|
|---|
| 405 | dsdy = oneOverArea * (eMaj.dx * eBot_ds - eMaj_ds * eBot.dx);
|
|---|
| 406 |
|
|---|
| 407 |
|
|---|
| 408 | if (VB->TexCoordPtr[0]->size > 1)
|
|---|
| 409 | {
|
|---|
| 410 | eMaj_dt = VB->TexCoordPtr[0]->data[vMax][1]*wMax - VB->TexCoordPtr[0]->data[vMin][1]*wMin;
|
|---|
| 411 | eBot_dt = VB->TexCoordPtr[0]->data[vMid][1]*wMid - VB->TexCoordPtr[0]->data[vMin][1]*wMin;
|
|---|
| 412 | dtdx = oneOverArea * (eMaj_dt * eBot.dy - eMaj.dy * eBot_dt);
|
|---|
| 413 | dtdy = oneOverArea * (eMaj.dx * eBot_dt - eMaj_dt * eBot.dx);
|
|---|
| 414 | } else {
|
|---|
| 415 | dtdx = 0;
|
|---|
| 416 | dtdy = 0;
|
|---|
| 417 | }
|
|---|
| 418 |
|
|---|
| 419 | if (VB->TexCoordPtr[0]->size > 2)
|
|---|
| 420 | {
|
|---|
| 421 | eMaj_du = VB->TexCoordPtr[0]->data[vMax][2]*wMax - VB->TexCoordPtr[0]->data[vMin][2]*wMin;
|
|---|
| 422 | eBot_du = VB->TexCoordPtr[0]->data[vMid][2]*wMid - VB->TexCoordPtr[0]->data[vMin][2]*wMin;
|
|---|
| 423 | dudx = oneOverArea * (eMaj_du * eBot.dy - eMaj.dy * eBot_du);
|
|---|
| 424 | dudy = oneOverArea * (eMaj.dx * eBot_du - eMaj_du * eBot.dx);
|
|---|
| 425 | } else {
|
|---|
| 426 | dudx = 0;
|
|---|
| 427 | dudy = 0;
|
|---|
| 428 | }
|
|---|
| 429 |
|
|---|
| 430 | if (VB->TexCoordPtr[0]->size > 3)
|
|---|
| 431 | {
|
|---|
| 432 | eMaj_dv = VB->TexCoordPtr[0]->data[vMax][3]*wMax - VB->TexCoordPtr[0]->data[vMin][3]*wMin;
|
|---|
| 433 | eBot_dv = VB->TexCoordPtr[0]->data[vMid][3]*wMid - VB->TexCoordPtr[0]->data[vMin][3]*wMin;
|
|---|
| 434 | dvdx = oneOverArea * (eMaj_dv * eBot.dy - eMaj.dy * eBot_dv);
|
|---|
| 435 | dvdy = oneOverArea * (eMaj.dx * eBot_dv - eMaj_dv * eBot.dx);
|
|---|
| 436 | } else {
|
|---|
| 437 | eMaj_dv = wMax - wMin;
|
|---|
| 438 | eBot_dv = wMid - wMin;
|
|---|
| 439 | dvdx = oneOverArea * (eMaj_dv * eBot.dy - eMaj.dy * eBot_dv);
|
|---|
| 440 | dvdy = oneOverArea * (eMaj.dx * eBot_dv - eMaj_dv * eBot.dx);
|
|---|
| 441 | }
|
|---|
| 442 | }
|
|---|
| 443 | #endif
|
|---|
| 444 | #if INTERP_STUV1
|
|---|
| 445 | {
|
|---|
| 446 | GLfloat wMax = VB->Win.data[vMax][3];
|
|---|
| 447 | GLfloat wMin = VB->Win.data[vMin][3];
|
|---|
| 448 | GLfloat wMid = VB->Win.data[vMid][3];
|
|---|
| 449 | GLfloat eMaj_ds, eBot_ds;
|
|---|
| 450 | GLfloat eMaj_dt, eBot_dt;
|
|---|
| 451 | GLfloat eMaj_du, eBot_du;
|
|---|
| 452 | GLfloat eMaj_dv, eBot_dv;
|
|---|
| 453 | eMaj_ds = VB->TexCoordPtr[1]->data[vMax][0]*wMax - VB->TexCoordPtr[1]->data[vMin][0]*wMin;
|
|---|
| 454 | eBot_ds = VB->TexCoordPtr[1]->data[vMid][0]*wMid - VB->TexCoordPtr[1]->data[vMin][0]*wMin;
|
|---|
| 455 | ds1dx = oneOverArea * (eMaj_ds * eBot.dy - eMaj.dy * eBot_ds);
|
|---|
| 456 | ds1dy = oneOverArea * (eMaj.dx * eBot_ds - eMaj_ds * eBot.dx);
|
|---|
| 457 |
|
|---|
| 458 | if (VB->TexCoordPtr[1]->size > 1)
|
|---|
| 459 | {
|
|---|
| 460 | eMaj_dt = VB->TexCoordPtr[1]->data[vMax][1]*wMax - VB->TexCoordPtr[1]->data[vMin][1]*wMin;
|
|---|
| 461 | eBot_dt = VB->TexCoordPtr[1]->data[vMid][1]*wMid - VB->TexCoordPtr[1]->data[vMin][1]*wMin;
|
|---|
| 462 | dt1dx = oneOverArea * (eMaj_dt * eBot.dy - eMaj.dy * eBot_dt);
|
|---|
| 463 | dt1dy = oneOverArea * (eMaj.dx * eBot_dt - eMaj_dt * eBot.dx);
|
|---|
| 464 | }
|
|---|
| 465 | else
|
|---|
| 466 | {
|
|---|
| 467 | dt1dx = 0;
|
|---|
| 468 | dt1dy = 0;
|
|---|
| 469 | }
|
|---|
| 470 |
|
|---|
| 471 | if (VB->TexCoordPtr[1]->size > 2)
|
|---|
| 472 | {
|
|---|
| 473 | eMaj_du = VB->TexCoordPtr[1]->data[vMax][2]*wMax - VB->TexCoordPtr[1]->data[vMin][2]*wMin;
|
|---|
| 474 | eBot_du = VB->TexCoordPtr[1]->data[vMid][2]*wMid - VB->TexCoordPtr[1]->data[vMin][2]*wMin;
|
|---|
| 475 | du1dx = oneOverArea * (eMaj_du * eBot.dy - eMaj.dy * eBot_du);
|
|---|
| 476 | du1dy = oneOverArea * (eMaj.dx * eBot_du - eMaj_du * eBot.dx);
|
|---|
| 477 | }
|
|---|
| 478 | else
|
|---|
| 479 | {
|
|---|
| 480 | du1dx = 0;
|
|---|
| 481 | du1dy = 0;
|
|---|
| 482 | }
|
|---|
| 483 |
|
|---|
| 484 | if (VB->TexCoordPtr[1]->size > 3)
|
|---|
| 485 | {
|
|---|
| 486 | eMaj_dv = VB->TexCoordPtr[1]->data[vMax][3]*wMax - VB->TexCoordPtr[1]->data[vMin][3]*wMin;
|
|---|
| 487 | eBot_dv = VB->TexCoordPtr[1]->data[vMid][3]*wMid - VB->TexCoordPtr[1]->data[vMin][3]*wMin;
|
|---|
| 488 | dv1dx = oneOverArea * (eMaj_dv * eBot.dy - eMaj.dy * eBot_dv);
|
|---|
| 489 | dv1dy = oneOverArea * (eMaj.dx * eBot_dv - eMaj_dv * eBot.dx);
|
|---|
| 490 | }
|
|---|
| 491 | else
|
|---|
| 492 | {
|
|---|
| 493 | eMaj_dv = wMax - wMin;
|
|---|
| 494 | eBot_dv = wMid - wMin;
|
|---|
| 495 | dv1dx = oneOverArea * (eMaj_dv * eBot.dy - eMaj.dy * eBot_dv);
|
|---|
| 496 | dv1dy = oneOverArea * (eMaj.dx * eBot_dv - eMaj_dv * eBot.dx);
|
|---|
| 497 | }
|
|---|
| 498 | }
|
|---|
| 499 | #endif
|
|---|
| 500 |
|
|---|
| 501 | /*
|
|---|
| 502 | * We always sample at pixel centers. However, we avoid
|
|---|
| 503 | * explicit half-pixel offsets in this code by incorporating
|
|---|
| 504 | * the proper offset in each of x and y during the
|
|---|
| 505 | * transformation to window coordinates.
|
|---|
| 506 | *
|
|---|
| 507 | * We also apply the usual rasterization rules to prevent
|
|---|
| 508 | * cracks and overlaps. A pixel is considered inside a
|
|---|
| 509 | * subtriangle if it meets all of four conditions: it is on or
|
|---|
| 510 | * to the right of the left edge, strictly to the left of the
|
|---|
| 511 | * right edge, on or below the top edge, and strictly above
|
|---|
| 512 | * the bottom edge. (Some edges may be degenerate.)
|
|---|
| 513 | *
|
|---|
| 514 | * The following discussion assumes left-to-right scanning
|
|---|
| 515 | * (that is, the major edge is on the left); the right-to-left
|
|---|
| 516 | * case is a straightforward variation.
|
|---|
| 517 | *
|
|---|
| 518 | * We start by finding the half-integral y coordinate that is
|
|---|
| 519 | * at or below the top of the triangle. This gives us the
|
|---|
| 520 | * first scan line that could possibly contain pixels that are
|
|---|
| 521 | * inside the triangle.
|
|---|
| 522 | *
|
|---|
| 523 | * Next we creep down the major edge until we reach that y,
|
|---|
| 524 | * and compute the corresponding x coordinate on the edge.
|
|---|
| 525 | * Then we find the half-integral x that lies on or just
|
|---|
| 526 | * inside the edge. This is the first pixel that might lie in
|
|---|
| 527 | * the interior of the triangle. (We won't know for sure
|
|---|
| 528 | * until we check the other edges.)
|
|---|
| 529 | *
|
|---|
| 530 | * As we rasterize the triangle, we'll step down the major
|
|---|
| 531 | * edge. For each step in y, we'll move an integer number
|
|---|
| 532 | * of steps in x. There are two possible x step sizes, which
|
|---|
| 533 | * we'll call the ``inner'' step (guaranteed to land on the
|
|---|
| 534 | * edge or inside it) and the ``outer'' step (guaranteed to
|
|---|
| 535 | * land on the edge or outside it). The inner and outer steps
|
|---|
| 536 | * differ by one. During rasterization we maintain an error
|
|---|
| 537 | * term that indicates our distance from the true edge, and
|
|---|
| 538 | * select either the inner step or the outer step, whichever
|
|---|
| 539 | * gets us to the first pixel that falls inside the triangle.
|
|---|
| 540 | *
|
|---|
| 541 | * All parameters (z, red, etc.) as well as the buffer
|
|---|
| 542 | * addresses for color and z have inner and outer step values,
|
|---|
| 543 | * so that we can increment them appropriately. This method
|
|---|
| 544 | * eliminates the need to adjust parameters by creeping a
|
|---|
| 545 | * sub-pixel amount into the triangle at each scanline.
|
|---|
| 546 | */
|
|---|
| 547 |
|
|---|
| 548 | {
|
|---|
| 549 | int subTriangle;
|
|---|
| 550 | GLfixed fx, fxLeftEdge, fxRightEdge, fdxLeftEdge, fdxRightEdge;
|
|---|
| 551 | GLfixed fdxOuter;
|
|---|
| 552 | int idxOuter;
|
|---|
| 553 | float dxOuter;
|
|---|
| 554 | GLfixed fError, fdError;
|
|---|
| 555 | float adjx, adjy;
|
|---|
| 556 | GLfixed fy;
|
|---|
| 557 | int iy;
|
|---|
| 558 | #ifdef PIXEL_ADDRESS
|
|---|
| 559 | PIXEL_TYPE *pRow;
|
|---|
| 560 | int dPRowOuter, dPRowInner; /* offset in bytes */
|
|---|
| 561 | #endif
|
|---|
| 562 | #if INTERP_Z
|
|---|
| 563 | GLdepth *zRow;
|
|---|
| 564 | int dZRowOuter, dZRowInner; /* offset in bytes */
|
|---|
| 565 | GLfixed fz, fdzOuter, fdzInner;
|
|---|
| 566 | #endif
|
|---|
| 567 | #if INTERP_RGB
|
|---|
| 568 | GLfixed fr, fdrOuter, fdrInner;
|
|---|
| 569 | GLfixed fg, fdgOuter, fdgInner;
|
|---|
| 570 | GLfixed fb, fdbOuter, fdbInner;
|
|---|
| 571 | #endif
|
|---|
| 572 | #if INTERP_SPEC
|
|---|
| 573 | GLfixed fsr, fdsrOuter, fdsrInner;
|
|---|
| 574 | GLfixed fsg, fdsgOuter, fdsgInner;
|
|---|
| 575 | GLfixed fsb, fdsbOuter, fdsbInner;
|
|---|
| 576 | #endif
|
|---|
| 577 | #if INTERP_ALPHA
|
|---|
| 578 | GLfixed fa, fdaOuter, fdaInner;
|
|---|
| 579 | #endif
|
|---|
| 580 | #if INTERP_INDEX
|
|---|
| 581 | GLfixed fi, fdiOuter, fdiInner;
|
|---|
| 582 | #endif
|
|---|
| 583 | #if INTERP_INT_ST
|
|---|
| 584 | GLfixed fs, fdsOuter, fdsInner;
|
|---|
| 585 | GLfixed ft, fdtOuter, fdtInner;
|
|---|
| 586 | #endif
|
|---|
| 587 | #if INTERP_STUV
|
|---|
| 588 | GLfloat sLeft, dsOuter, dsInner;
|
|---|
| 589 | GLfloat tLeft, dtOuter, dtInner;
|
|---|
| 590 | GLfloat uLeft, duOuter, duInner;
|
|---|
| 591 | GLfloat vLeft, dvOuter, dvInner;
|
|---|
| 592 | #endif
|
|---|
| 593 | #if INTERP_STUV1
|
|---|
| 594 | GLfloat s1Left, ds1Outer, ds1Inner;
|
|---|
| 595 | GLfloat t1Left, dt1Outer, dt1Inner;
|
|---|
| 596 | GLfloat u1Left, du1Outer, du1Inner;
|
|---|
| 597 | GLfloat v1Left, dv1Outer, dv1Inner;
|
|---|
| 598 | #endif
|
|---|
| 599 |
|
|---|
| 600 | for (subTriangle=0; subTriangle<=1; subTriangle++) {
|
|---|
| 601 | EdgeT *eLeft, *eRight;
|
|---|
| 602 | int setupLeft, setupRight;
|
|---|
| 603 | int lines;
|
|---|
| 604 |
|
|---|
| 605 | if (subTriangle==0) {
|
|---|
| 606 | /* bottom half */
|
|---|
| 607 | if (ltor) {
|
|---|
| 608 | eLeft = &eMaj;
|
|---|
| 609 | eRight = &eBot;
|
|---|
| 610 | lines = eRight->lines;
|
|---|
| 611 | setupLeft = 1;
|
|---|
| 612 | setupRight = 1;
|
|---|
| 613 | }
|
|---|
| 614 | else {
|
|---|
| 615 | eLeft = &eBot;
|
|---|
| 616 | eRight = &eMaj;
|
|---|
| 617 | lines = eLeft->lines;
|
|---|
| 618 | setupLeft = 1;
|
|---|
| 619 | setupRight = 1;
|
|---|
| 620 | }
|
|---|
| 621 | }
|
|---|
| 622 | else {
|
|---|
| 623 | /* top half */
|
|---|
| 624 | if (ltor) {
|
|---|
| 625 | eLeft = &eMaj;
|
|---|
| 626 | eRight = &eTop;
|
|---|
| 627 | lines = eRight->lines;
|
|---|
| 628 | setupLeft = 0;
|
|---|
| 629 | setupRight = 1;
|
|---|
| 630 | }
|
|---|
| 631 | else {
|
|---|
| 632 | eLeft = &eTop;
|
|---|
| 633 | eRight = &eMaj;
|
|---|
| 634 | lines = eLeft->lines;
|
|---|
| 635 | setupLeft = 1;
|
|---|
| 636 | setupRight = 0;
|
|---|
| 637 | }
|
|---|
| 638 | if (lines==0) return;
|
|---|
| 639 | }
|
|---|
| 640 |
|
|---|
| 641 | if (setupLeft && eLeft->lines>0) {
|
|---|
| 642 | GLint vLower;
|
|---|
| 643 | GLfixed fsx = eLeft->fsx;
|
|---|
| 644 | fx = FixedCeil(fsx);
|
|---|
| 645 | fError = fx - fsx - FIXED_ONE;
|
|---|
| 646 | fxLeftEdge = fsx - FIXED_EPSILON;
|
|---|
| 647 | fdxLeftEdge = eLeft->fdxdy;
|
|---|
| 648 | fdxOuter = FixedFloor(fdxLeftEdge - FIXED_EPSILON);
|
|---|
| 649 | fdError = fdxOuter - fdxLeftEdge + FIXED_ONE;
|
|---|
| 650 | idxOuter = FixedToInt(fdxOuter);
|
|---|
| 651 | dxOuter = (float) idxOuter;
|
|---|
| 652 | (void) dxOuter;
|
|---|
| 653 |
|
|---|
| 654 | fy = eLeft->fsy;
|
|---|
| 655 | iy = FixedToInt(fy);
|
|---|
| 656 |
|
|---|
| 657 | adjx = (float)(fx - eLeft->fx0); /* SCALED! */
|
|---|
| 658 | adjy = eLeft->adjy; /* SCALED! */
|
|---|
| 659 | (void) adjx; /* silence compiler warnings */
|
|---|
| 660 | (void) adjy; /* silence compiler warnings */
|
|---|
| 661 |
|
|---|
| 662 | vLower = eLeft->v0;
|
|---|
| 663 | (void) vLower; /* silence compiler warnings */
|
|---|
| 664 |
|
|---|
| 665 | #ifdef PIXEL_ADDRESS
|
|---|
| 666 | {
|
|---|
| 667 | pRow = (PIXEL_TYPE *) PIXEL_ADDRESS( FixedToInt(fxLeftEdge), iy );
|
|---|
| 668 | dPRowOuter = -((int)BYTES_PER_ROW) + idxOuter * sizeof(PIXEL_TYPE);
|
|---|
| 669 | /* negative because Y=0 at bottom and increases upward */
|
|---|
| 670 | }
|
|---|
| 671 | #endif
|
|---|
| 672 | /*
|
|---|
| 673 | * Now we need the set of parameter (z, color, etc.) values at
|
|---|
| 674 | * the point (fx, fy). This gives us properly-sampled parameter
|
|---|
| 675 | * values that we can step from pixel to pixel. Furthermore,
|
|---|
| 676 | * although we might have intermediate results that overflow
|
|---|
| 677 | * the normal parameter range when we step temporarily outside
|
|---|
| 678 | * the triangle, we shouldn't overflow or underflow for any
|
|---|
| 679 | * pixel that's actually inside the triangle.
|
|---|
| 680 | */
|
|---|
| 681 |
|
|---|
| 682 | #if INTERP_Z
|
|---|
| 683 | {
|
|---|
| 684 | GLfloat z0, tmp;
|
|---|
| 685 | z0 = VB->Win.data[vLower][2] + ctx->PolygonZoffset;
|
|---|
| 686 | #if DEPTH_BITS==16
|
|---|
| 687 | /* interpolate fixed-pt values */
|
|---|
| 688 | tmp = (z0 * FIXED_SCALE + dzdx * adjx + dzdy * adjy) + FIXED_HALF;
|
|---|
| 689 | if (tmp < MAX_GLUINT/2)
|
|---|
| 690 | fz = (GLfixed) tmp;
|
|---|
| 691 | else
|
|---|
| 692 | fz = MAX_GLUINT/2;
|
|---|
| 693 | fdzOuter = SignedFloatToFixed(dzdy + dxOuter * dzdx);
|
|---|
| 694 | #else
|
|---|
| 695 | (void) tmp;
|
|---|
| 696 | /* interpolate depth values exactly */
|
|---|
| 697 | fz = (GLint) (z0 + dzdx*FixedToFloat(adjx) + dzdy*FixedToFloat(adjy));
|
|---|
| 698 | fdzOuter = (GLint) (dzdy + dxOuter * dzdx);
|
|---|
| 699 | #endif
|
|---|
| 700 | zRow = Z_ADDRESS( ctx, FixedToInt(fxLeftEdge), iy );
|
|---|
| 701 | dZRowOuter = (ctx->Buffer->Width + idxOuter) * sizeof(GLdepth);
|
|---|
| 702 | }
|
|---|
| 703 | #endif
|
|---|
| 704 | #if INTERP_RGB
|
|---|
| 705 | fr = (GLfixed)(IntToFixed(VB->ColorPtr->data[vLower][0]) + drdx * adjx + drdy * adjy)
|
|---|
| 706 | + FIXED_HALF;
|
|---|
| 707 | fdrOuter = SignedFloatToFixed(drdy + dxOuter * drdx);
|
|---|
| 708 |
|
|---|
| 709 | fg = (GLfixed)(IntToFixed(VB->ColorPtr->data[vLower][1]) + dgdx * adjx + dgdy * adjy)
|
|---|
| 710 | + FIXED_HALF;
|
|---|
| 711 | fdgOuter = SignedFloatToFixed(dgdy + dxOuter * dgdx);
|
|---|
| 712 |
|
|---|
| 713 | fb = (GLfixed)(IntToFixed(VB->ColorPtr->data[vLower][2]) + dbdx * adjx + dbdy * adjy)
|
|---|
| 714 | + FIXED_HALF;
|
|---|
| 715 | fdbOuter = SignedFloatToFixed(dbdy + dxOuter * dbdx);
|
|---|
| 716 | #endif
|
|---|
| 717 | #if INTERP_SPEC
|
|---|
| 718 | fsr = (GLfixed)(IntToFixed(VB->Specular[vLower][0]) + dsrdx * adjx + dsrdy * adjy)
|
|---|
| 719 | + FIXED_HALF;
|
|---|
| 720 | fdsrOuter = SignedFloatToFixed(dsrdy + dxOuter * dsrdx);
|
|---|
| 721 |
|
|---|
| 722 | fsg = (GLfixed)(IntToFixed(VB->Specular[vLower][1]) + dsgdx * adjx + dsgdy * adjy)
|
|---|
| 723 | + FIXED_HALF;
|
|---|
| 724 | fdsgOuter = SignedFloatToFixed(dsgdy + dxOuter * dsgdx);
|
|---|
| 725 |
|
|---|
| 726 | fsb = (GLfixed)(IntToFixed(VB->Specular[vLower][2]) + dsbdx * adjx + dsbdy * adjy)
|
|---|
| 727 | + FIXED_HALF;
|
|---|
| 728 | fdsbOuter = SignedFloatToFixed(dsbdy + dxOuter * dsbdx);
|
|---|
| 729 | #endif
|
|---|
| 730 | #if INTERP_ALPHA
|
|---|
| 731 | fa = (GLfixed)(IntToFixed(VB->ColorPtr->data[vLower][3]) + dadx * adjx + dady * adjy)
|
|---|
| 732 | + FIXED_HALF;
|
|---|
| 733 | fdaOuter = SignedFloatToFixed(dady + dxOuter * dadx);
|
|---|
| 734 | #endif
|
|---|
| 735 | #if INTERP_INDEX
|
|---|
| 736 | fi = (GLfixed)(VB->IndexPtr->data[vLower] * FIXED_SCALE + didx * adjx
|
|---|
| 737 | + didy * adjy) + FIXED_HALF;
|
|---|
| 738 | fdiOuter = SignedFloatToFixed(didy + dxOuter * didx);
|
|---|
| 739 | #endif
|
|---|
| 740 | #if INTERP_INT_ST
|
|---|
| 741 | {
|
|---|
| 742 | GLfloat s0, t0;
|
|---|
| 743 | s0 = VB->TexCoordPtr[0]->data[vLower][0] * S_SCALE;
|
|---|
| 744 | fs = (GLfixed)(s0 * FIXED_SCALE + dsdx * adjx + dsdy * adjy) + FIXED_HALF;
|
|---|
| 745 | fdsOuter = SignedFloatToFixed(dsdy + dxOuter * dsdx);
|
|---|
| 746 |
|
|---|
| 747 | if (VB->TexCoordPtr[0]->size > 1)
|
|---|
| 748 | {
|
|---|
| 749 | t0 = VB->TexCoordPtr[0]->data[vLower][1] * T_SCALE;
|
|---|
| 750 | ft = (GLfixed)(t0 * FIXED_SCALE + dtdx * adjx + dtdy * adjy) + FIXED_HALF;
|
|---|
| 751 | fdtOuter = SignedFloatToFixed(dtdy + dxOuter * dtdx);
|
|---|
| 752 | }
|
|---|
| 753 | else
|
|---|
| 754 | {
|
|---|
| 755 | t0 = 0;
|
|---|
| 756 | ft = (GLfixed) FIXED_HALF;
|
|---|
| 757 | fdtOuter = SignedFloatToFixed(0);
|
|---|
| 758 | }
|
|---|
| 759 | }
|
|---|
| 760 | #endif
|
|---|
| 761 | #if INTERP_STUV
|
|---|
| 762 | {
|
|---|
| 763 | GLfloat invW = VB->Win.data[vLower][3];
|
|---|
| 764 | GLfloat s0, t0, u0, v0;
|
|---|
| 765 | s0 = VB->TexCoordPtr[0]->data[vLower][0] * invW;
|
|---|
| 766 | sLeft = s0 + (dsdx * adjx + dsdy * adjy) * (1.0F/FIXED_SCALE);
|
|---|
| 767 | dsOuter = dsdy + dxOuter * dsdx;
|
|---|
| 768 | if (VB->TexCoordPtr[0]->size > 1)
|
|---|
| 769 | {
|
|---|
| 770 | t0 = VB->TexCoordPtr[0]->data[vLower][1] * invW;
|
|---|
| 771 | tLeft = t0 + (dtdx * adjx + dtdy * adjy) * (1.0F/FIXED_SCALE);
|
|---|
| 772 | dtOuter = dtdy + dxOuter * dtdx;
|
|---|
| 773 | } else {
|
|---|
| 774 | tLeft = dtOuter = 0;
|
|---|
| 775 | }
|
|---|
| 776 | if (VB->TexCoordPtr[0]->size > 2)
|
|---|
| 777 | {
|
|---|
| 778 | u0 = VB->TexCoordPtr[0]->data[vLower][2] * invW;
|
|---|
| 779 | uLeft = u0 + (dudx * adjx + dudy * adjy) * (1.0F/FIXED_SCALE);
|
|---|
| 780 | duOuter = dudy + dxOuter * dudx;
|
|---|
| 781 | } else {
|
|---|
| 782 | uLeft = duOuter = 0;
|
|---|
| 783 | }
|
|---|
| 784 | if (VB->TexCoordPtr[0]->size > 3)
|
|---|
| 785 | {
|
|---|
| 786 | v0 = VB->TexCoordPtr[0]->data[vLower][3] * invW;
|
|---|
| 787 | } else {
|
|---|
| 788 | v0 = invW;
|
|---|
| 789 | }
|
|---|
| 790 | vLeft = v0 + (dvdx * adjx + dvdy * adjy) * (1.0F/FIXED_SCALE);
|
|---|
| 791 | dvOuter = dvdy + dxOuter * dvdx;
|
|---|
| 792 | }
|
|---|
| 793 | #endif
|
|---|
| 794 | #if INTERP_STUV1
|
|---|
| 795 | {
|
|---|
| 796 | GLfloat invW = VB->Win.data[vLower][3];
|
|---|
| 797 | GLfloat s0, t0, u0, v0;
|
|---|
| 798 | s0 = VB->TexCoordPtr[1]->data[vLower][0] * invW;
|
|---|
| 799 | s1Left = s0 + (ds1dx * adjx + ds1dy * adjy) * (1.0F/FIXED_SCALE);
|
|---|
| 800 | ds1Outer = ds1dy + dxOuter * ds1dx;
|
|---|
| 801 | if (VB->TexCoordPtr[0]->size > 1)
|
|---|
| 802 | {
|
|---|
| 803 | t0 = VB->TexCoordPtr[1]->data[vLower][1] * invW;
|
|---|
| 804 | t1Left = t0 + (dt1dx * adjx + dt1dy * adjy) * (1.0F/FIXED_SCALE);
|
|---|
| 805 | dt1Outer = dt1dy + dxOuter * dt1dx;
|
|---|
| 806 | } else {
|
|---|
| 807 | t1Left = dt1Outer = 0;
|
|---|
| 808 | }
|
|---|
| 809 | if (VB->TexCoordPtr[0]->size > 2)
|
|---|
| 810 | {
|
|---|
| 811 | u0 = VB->TexCoordPtr[1]->data[vLower][2] * invW;
|
|---|
| 812 | u1Left = u0 + (du1dx * adjx + du1dy * adjy) * (1.0F/FIXED_SCALE);
|
|---|
| 813 | du1Outer = du1dy + dxOuter * du1dx;
|
|---|
| 814 | } else {
|
|---|
| 815 | u1Left = du1Outer = 0;
|
|---|
| 816 | }
|
|---|
| 817 | if (VB->TexCoordPtr[0]->size > 3)
|
|---|
| 818 | {
|
|---|
| 819 | v0 = VB->TexCoordPtr[1]->data[vLower][3] * invW;
|
|---|
| 820 | } else {
|
|---|
| 821 | v0 = invW;
|
|---|
| 822 | }
|
|---|
| 823 | v1Left = v0 + (dv1dx * adjx + dv1dy * adjy) * (1.0F/FIXED_SCALE);
|
|---|
| 824 | dv1Outer = dv1dy + dxOuter * dv1dx;
|
|---|
| 825 | }
|
|---|
| 826 | #endif
|
|---|
| 827 |
|
|---|
| 828 | } /*if setupLeft*/
|
|---|
| 829 |
|
|---|
| 830 |
|
|---|
| 831 | if (setupRight && eRight->lines>0) {
|
|---|
| 832 | fxRightEdge = eRight->fsx - FIXED_EPSILON;
|
|---|
| 833 | fdxRightEdge = eRight->fdxdy;
|
|---|
| 834 | }
|
|---|
| 835 |
|
|---|
| 836 | if (lines==0) {
|
|---|
| 837 | continue;
|
|---|
| 838 | }
|
|---|
| 839 |
|
|---|
| 840 |
|
|---|
| 841 | /* Rasterize setup */
|
|---|
| 842 | #ifdef PIXEL_ADDRESS
|
|---|
| 843 | dPRowInner = dPRowOuter + sizeof(PIXEL_TYPE);
|
|---|
| 844 | #endif
|
|---|
| 845 | #if INTERP_Z
|
|---|
| 846 | dZRowInner = dZRowOuter + sizeof(GLdepth);
|
|---|
| 847 | fdzInner = fdzOuter + fdzdx;
|
|---|
| 848 | #endif
|
|---|
| 849 | #if INTERP_RGB
|
|---|
| 850 | fdrInner = fdrOuter + fdrdx;
|
|---|
| 851 | fdgInner = fdgOuter + fdgdx;
|
|---|
| 852 | fdbInner = fdbOuter + fdbdx;
|
|---|
| 853 | #endif
|
|---|
| 854 | #if INTERP_SPEC
|
|---|
| 855 | fdsrInner = fdsrOuter + fdsrdx;
|
|---|
| 856 | fdsgInner = fdsgOuter + fdsgdx;
|
|---|
| 857 | fdsbInner = fdsbOuter + fdsbdx;
|
|---|
| 858 | #endif
|
|---|
| 859 | #if INTERP_ALPHA
|
|---|
| 860 | fdaInner = fdaOuter + fdadx;
|
|---|
| 861 | #endif
|
|---|
| 862 | #if INTERP_INDEX
|
|---|
| 863 | fdiInner = fdiOuter + fdidx;
|
|---|
| 864 | #endif
|
|---|
| 865 | #if INTERP_INT_ST
|
|---|
| 866 | fdsInner = fdsOuter + fdsdx;
|
|---|
| 867 | fdtInner = fdtOuter + fdtdx;
|
|---|
| 868 | #endif
|
|---|
| 869 | #if INTERP_STUV
|
|---|
| 870 | dsInner = dsOuter + dsdx;
|
|---|
| 871 | dtInner = dtOuter + dtdx;
|
|---|
| 872 | duInner = duOuter + dudx;
|
|---|
| 873 | dvInner = dvOuter + dvdx;
|
|---|
| 874 | #endif
|
|---|
| 875 | #if INTERP_STUV1
|
|---|
| 876 | ds1Inner = ds1Outer + ds1dx;
|
|---|
| 877 | dt1Inner = dt1Outer + dt1dx;
|
|---|
| 878 | du1Inner = du1Outer + du1dx;
|
|---|
| 879 | dv1Inner = dv1Outer + dv1dx;
|
|---|
| 880 | #endif
|
|---|
| 881 |
|
|---|
| 882 | while (lines>0) {
|
|---|
| 883 | /* initialize the span interpolants to the leftmost value */
|
|---|
| 884 | /* ff = fixed-pt fragment */
|
|---|
| 885 | #if INTERP_Z
|
|---|
| 886 | GLfixed ffz = fz;
|
|---|
| 887 | /*GLdepth *zp = zRow;*/
|
|---|
| 888 | #endif
|
|---|
| 889 | #if INTERP_RGB
|
|---|
| 890 | GLfixed ffr = fr, ffg = fg, ffb = fb;
|
|---|
| 891 | #endif
|
|---|
| 892 | #if INTERP_SPEC
|
|---|
| 893 | GLfixed ffsr = fsr, ffsg = fsg, ffsb = fsb;
|
|---|
| 894 | #endif
|
|---|
| 895 | #if INTERP_ALPHA
|
|---|
| 896 | GLfixed ffa = fa;
|
|---|
| 897 | #endif
|
|---|
| 898 | #if INTERP_INDEX
|
|---|
| 899 | GLfixed ffi = fi;
|
|---|
| 900 | #endif
|
|---|
| 901 | #if INTERP_INT_ST
|
|---|
| 902 | GLfixed ffs = fs, fft = ft;
|
|---|
| 903 | #endif
|
|---|
| 904 | #if INTERP_STUV
|
|---|
| 905 | GLfloat ss = sLeft, tt = tLeft, uu = uLeft, vv = vLeft;
|
|---|
| 906 | #endif
|
|---|
| 907 | #if INTERP_STUV1
|
|---|
| 908 | GLfloat ss1 = s1Left, tt1 = t1Left, uu1 = u1Left, vv1 = v1Left;
|
|---|
| 909 | #endif
|
|---|
| 910 | GLint left = FixedToInt(fxLeftEdge);
|
|---|
| 911 | GLint right = FixedToInt(fxRightEdge);
|
|---|
| 912 |
|
|---|
| 913 | #if INTERP_RGB
|
|---|
| 914 | {
|
|---|
| 915 | /* need this to accomodate round-off errors */
|
|---|
| 916 | GLfixed ffrend = ffr+(right-left-1)*fdrdx;
|
|---|
| 917 | GLfixed ffgend = ffg+(right-left-1)*fdgdx;
|
|---|
| 918 | GLfixed ffbend = ffb+(right-left-1)*fdbdx;
|
|---|
| 919 | if (ffrend<0) ffr -= ffrend;
|
|---|
| 920 | if (ffgend<0) ffg -= ffgend;
|
|---|
| 921 | if (ffbend<0) ffb -= ffbend;
|
|---|
| 922 | if (ffr<0) ffr = 0;
|
|---|
| 923 | if (ffg<0) ffg = 0;
|
|---|
| 924 | if (ffb<0) ffb = 0;
|
|---|
| 925 | }
|
|---|
| 926 | #endif
|
|---|
| 927 | #if INTERP_SPEC
|
|---|
| 928 | {
|
|---|
| 929 | /* need this to accomodate round-off errors */
|
|---|
| 930 | GLfixed ffsrend = ffsr+(right-left-1)*fdsrdx;
|
|---|
| 931 | GLfixed ffsgend = ffsg+(right-left-1)*fdsgdx;
|
|---|
| 932 | GLfixed ffsbend = ffsb+(right-left-1)*fdsbdx;
|
|---|
| 933 | if (ffsrend<0) ffsr -= ffsrend;
|
|---|
| 934 | if (ffsgend<0) ffsg -= ffsgend;
|
|---|
| 935 | if (ffsbend<0) ffsb -= ffsbend;
|
|---|
| 936 | if (ffsr<0) ffsr = 0;
|
|---|
| 937 | if (ffsg<0) ffsg = 0;
|
|---|
| 938 | if (ffsb<0) ffsb = 0;
|
|---|
| 939 | }
|
|---|
| 940 | #endif
|
|---|
| 941 | #if INTERP_ALPHA
|
|---|
| 942 | {
|
|---|
| 943 | GLfixed ffaend = ffa+(right-left-1)*fdadx;
|
|---|
| 944 | if (ffaend<0) ffa -= ffaend;
|
|---|
| 945 | if (ffa<0) ffa = 0;
|
|---|
| 946 | }
|
|---|
| 947 | #endif
|
|---|
| 948 | #if INTERP_INDEX
|
|---|
| 949 | if (ffi<0) ffi = 0;
|
|---|
| 950 | #endif
|
|---|
| 951 |
|
|---|
| 952 | INNER_LOOP( left, right, iy );
|
|---|
| 953 |
|
|---|
| 954 | /*
|
|---|
| 955 | * Advance to the next scan line. Compute the
|
|---|
| 956 | * new edge coordinates, and adjust the
|
|---|
| 957 | * pixel-center x coordinate so that it stays
|
|---|
| 958 | * on or inside the major edge.
|
|---|
| 959 | */
|
|---|
| 960 | iy++;
|
|---|
| 961 | lines--;
|
|---|
| 962 |
|
|---|
| 963 | fxLeftEdge += fdxLeftEdge;
|
|---|
| 964 | fxRightEdge += fdxRightEdge;
|
|---|
| 965 |
|
|---|
| 966 |
|
|---|
| 967 | fError += fdError;
|
|---|
| 968 | if (fError >= 0) {
|
|---|
| 969 | fError -= FIXED_ONE;
|
|---|
| 970 | #ifdef PIXEL_ADDRESS
|
|---|
| 971 | pRow = (PIXEL_TYPE*) ((GLubyte*)pRow + dPRowOuter);
|
|---|
| 972 | #endif
|
|---|
| 973 | #if INTERP_Z
|
|---|
| 974 | zRow = (GLdepth*) ((GLubyte*)zRow + dZRowOuter);
|
|---|
| 975 | fz += fdzOuter;
|
|---|
| 976 | #endif
|
|---|
| 977 | #if INTERP_RGB
|
|---|
| 978 | fr += fdrOuter; fg += fdgOuter; fb += fdbOuter;
|
|---|
| 979 | #endif
|
|---|
| 980 | #if INTERP_SPEC
|
|---|
| 981 | fsr += fdsrOuter; fsg += fdsgOuter; fsb += fdsbOuter;
|
|---|
| 982 | #endif
|
|---|
| 983 | #if INTERP_ALPHA
|
|---|
| 984 | fa += fdaOuter;
|
|---|
| 985 | #endif
|
|---|
| 986 | #if INTERP_INDEX
|
|---|
| 987 | fi += fdiOuter;
|
|---|
| 988 | #endif
|
|---|
| 989 | #if INTERP_INT_ST
|
|---|
| 990 | fs += fdsOuter; ft += fdtOuter;
|
|---|
| 991 | #endif
|
|---|
| 992 | #if INTERP_STUV
|
|---|
| 993 | sLeft += dsOuter;
|
|---|
| 994 | tLeft += dtOuter;
|
|---|
| 995 | uLeft += duOuter;
|
|---|
| 996 | vLeft += dvOuter;
|
|---|
| 997 | #endif
|
|---|
| 998 | #if INTERP_STUV1
|
|---|
| 999 | s1Left += ds1Outer;
|
|---|
| 1000 | t1Left += dt1Outer;
|
|---|
| 1001 | u1Left += du1Outer;
|
|---|
| 1002 | v1Left += dv1Outer;
|
|---|
| 1003 | #endif
|
|---|
| 1004 | }
|
|---|
| 1005 | else {
|
|---|
| 1006 | #ifdef PIXEL_ADDRESS
|
|---|
| 1007 | pRow = (PIXEL_TYPE*) ((GLubyte*)pRow + dPRowInner);
|
|---|
| 1008 | #endif
|
|---|
| 1009 | #if INTERP_Z
|
|---|
| 1010 | zRow = (GLdepth*) ((GLubyte*)zRow + dZRowInner);
|
|---|
| 1011 | fz += fdzInner;
|
|---|
| 1012 | #endif
|
|---|
| 1013 | #if INTERP_RGB
|
|---|
| 1014 | fr += fdrInner; fg += fdgInner; fb += fdbInner;
|
|---|
| 1015 | #endif
|
|---|
| 1016 | #if INTERP_SPEC
|
|---|
| 1017 | fsr += fdsrInner; fsg += fdsgInner; fsb += fdsbInner;
|
|---|
| 1018 | #endif
|
|---|
| 1019 | #if INTERP_ALPHA
|
|---|
| 1020 | fa += fdaInner;
|
|---|
| 1021 | #endif
|
|---|
| 1022 | #if INTERP_INDEX
|
|---|
| 1023 | fi += fdiInner;
|
|---|
| 1024 | #endif
|
|---|
| 1025 | #if INTERP_INT_ST
|
|---|
| 1026 | fs += fdsInner; ft += fdtInner;
|
|---|
| 1027 | #endif
|
|---|
| 1028 | #if INTERP_STUV
|
|---|
| 1029 | sLeft += dsInner;
|
|---|
| 1030 | tLeft += dtInner;
|
|---|
| 1031 | uLeft += duInner;
|
|---|
| 1032 | vLeft += dvInner;
|
|---|
| 1033 | #endif
|
|---|
| 1034 | #if INTERP_STUV1
|
|---|
| 1035 | s1Left += ds1Inner;
|
|---|
| 1036 | t1Left += dt1Inner;
|
|---|
| 1037 | u1Left += du1Inner;
|
|---|
| 1038 | v1Left += dv1Inner;
|
|---|
| 1039 | #endif
|
|---|
| 1040 | }
|
|---|
| 1041 | } /*while lines>0*/
|
|---|
| 1042 |
|
|---|
| 1043 | } /* for subTriangle */
|
|---|
| 1044 |
|
|---|
| 1045 | }
|
|---|
| 1046 | }
|
|---|
| 1047 | }
|
|---|
| 1048 |
|
|---|
| 1049 | #undef SETUP_CODE
|
|---|
| 1050 | #undef INNER_LOOP
|
|---|
| 1051 |
|
|---|
| 1052 | #undef PIXEL_TYPE
|
|---|
| 1053 | #undef BYTES_PER_ROW
|
|---|
| 1054 | #undef PIXEL_ADDRESS
|
|---|
| 1055 |
|
|---|
| 1056 | #undef INTERP_Z
|
|---|
| 1057 | #undef INTERP_RGB
|
|---|
| 1058 | #undef INTERP_SPEC
|
|---|
| 1059 | #undef INTERP_ALPHA
|
|---|
| 1060 | #undef INTERP_INDEX
|
|---|
| 1061 | #undef INTERP_INT_ST
|
|---|
| 1062 | #undef INTERP_STUV
|
|---|
| 1063 | #undef INTERP_STUV1
|
|---|
| 1064 |
|
|---|
| 1065 | #undef S_SCALE
|
|---|
| 1066 | #undef T_SCALE
|
|---|