source: trunk/src/opengl/mesa/alphabuf.c@ 3598

Last change on this file since 3598 was 3598, checked in by jeroen, 25 years ago

* empty log message *
File size: 8.0 KB
Line 
1/* $Id: alphabuf.c,v 1.3 2000-05-23 20:40:20 jeroen Exp $ */
2
3/*
4 * Mesa 3-D graphics library
5 * Version: 3.3
6 *
7 * Copyright (C) 1999 Brian Paul All Rights Reserved.
8 *
9 * Permission is hereby granted, free of charge, to any person obtaining a
10 * copy of this software and associated documentation files (the "Software"),
11 * to deal in the Software without restriction, including without limitation
12 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13 * and/or sell copies of the Software, and to permit persons to whom the
14 * Software is furnished to do so, subject to the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be included
17 * in all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
20 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
23 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
24 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 */
26
27
28
29
30
31/*
32 * Software alpha planes. Many frame buffers don't have alpha bits so
33 * we simulate them in software.
34 */
35
36#include <stdlib.h>
37
38#ifdef PC_HEADER
39#include "all.h"
40#else
41#include "glheader.h"
42#include "types.h"
43#include "alphabuf.h"
44#include "context.h"
45#include "macros.h"
46#include "mem.h"
47#endif
48
49
50
51#define ALPHA_DRAW_ADDR(X,Y) \
52 (ctx->DrawBuffer->Alpha + (Y) * ctx->DrawBuffer->Width + (X))
53
54#define ALPHA_READ_ADDR(X,Y) \
55 (ctx->ReadBuffer->Alpha + (Y) * ctx->ReadBuffer->Width + (X))
56
57
58
59/*
60 * Allocate new front/back/left/right alpha buffers.
61 * Input: ctx - the context
62 */
63static void
64alloc_alpha_buffers( GLcontext *ctx, GLframebuffer *buf )
65{
66 GLint bytes = buf->Width * buf->Height * sizeof(GLubyte);
67
68 ASSERT(ctx->Visual->SoftwareAlpha);
69
70 if (buf->FrontLeftAlpha) {
71 FREE( buf->FrontLeftAlpha );
72 }
73 buf->FrontLeftAlpha = (GLubyte *) MALLOC( bytes );
74 if (!buf->FrontLeftAlpha) {
75 /* out of memory */
76 gl_error( ctx, GL_OUT_OF_MEMORY,
77 "Couldn't allocate front-left alpha buffer" );
78 }
79
80 if (ctx->Visual->DBflag) {
81 if (buf->BackLeftAlpha) {
82 FREE( buf->BackLeftAlpha );
83 }
84 buf->BackLeftAlpha = (GLubyte *) MALLOC( bytes );
85 if (!buf->BackLeftAlpha) {
86 /* out of memory */
87 gl_error( ctx, GL_OUT_OF_MEMORY,
88 "Couldn't allocate back-left alpha buffer" );
89 }
90 }
91
92 if (ctx->Visual->StereoFlag) {
93 if (buf->FrontRightAlpha) {
94 FREE( buf->FrontRightAlpha );
95 }
96 buf->FrontRightAlpha = (GLubyte *) MALLOC( bytes );
97 if (!buf->FrontRightAlpha) {
98 /* out of memory */
99 gl_error( ctx, GL_OUT_OF_MEMORY,
100 "Couldn't allocate front-right alpha buffer" );
101 }
102
103 if (ctx->Visual->DBflag) {
104 if (buf->BackRightAlpha) {
105 FREE( buf->BackRightAlpha );
106 }
107 buf->BackRightAlpha = (GLubyte *) MALLOC( bytes );
108 if (!buf->BackRightAlpha) {
109 /* out of memory */
110 gl_error( ctx, GL_OUT_OF_MEMORY,
111 "Couldn't allocate back-right alpha buffer" );
112 }
113 }
114 }
115
116 if (ctx->Color.DriverDrawBuffer == GL_FRONT_LEFT)
117 buf->Alpha = buf->FrontLeftAlpha;
118 else if (ctx->Color.DriverDrawBuffer == GL_BACK_LEFT)
119 buf->Alpha = buf->BackLeftAlpha;
120 else if (ctx->Color.DriverDrawBuffer == GL_FRONT_RIGHT)
121 buf->Alpha = buf->FrontRightAlpha;
122 else if (ctx->Color.DriverDrawBuffer == GL_BACK_RIGHT)
123 buf->Alpha = buf->BackRightAlpha;
124}
125
126
127/*
128 * Allocate a new front and back alpha buffer.
129 */
130void gl_alloc_alpha_buffers( GLcontext *ctx )
131{
132 alloc_alpha_buffers( ctx, ctx->DrawBuffer );
133 if (ctx->ReadBuffer != ctx->DrawBuffer) {
134 alloc_alpha_buffers( ctx, ctx->ReadBuffer );
135 }
136}
137
138
139/*
140 * Clear all the alpha buffers
141 */
142void gl_clear_alpha_buffers( GLcontext *ctx )
143{
144 const GLubyte aclear = (GLint) (ctx->Color.ClearColor[3] * 255.0F);
145 GLuint bufferBit;
146
147 ASSERT(ctx->Visual->SoftwareAlpha);
148 ASSERT(ctx->Color.ColorMask[ACOMP]);
149
150 /* loop over four possible alpha buffers */
151 for (bufferBit = 1; bufferBit <= 8; bufferBit = bufferBit << 1) {
152 if (bufferBit & ctx->Color.DrawDestMask) {
153 GLubyte *buffer;
154 if (bufferBit == FRONT_LEFT_BIT) {
155 buffer = ctx->DrawBuffer->FrontLeftAlpha;
156 }
157 else if (bufferBit == FRONT_RIGHT_BIT) {
158 buffer = ctx->DrawBuffer->FrontRightAlpha;
159 }
160 else if (bufferBit == BACK_LEFT_BIT) {
161 buffer = ctx->DrawBuffer->BackLeftAlpha;
162 }
163 else {
164 buffer = ctx->DrawBuffer->BackRightAlpha;
165 }
166
167 if (ctx->Scissor.Enabled) {
168 /* clear scissor region */
169 GLint j;
170 GLint rowLen = ctx->DrawBuffer->Xmax - ctx->DrawBuffer->Xmin + 1;
171 GLint rows = ctx->DrawBuffer->Ymax - ctx->DrawBuffer->Ymin + 1;
172 GLubyte *aptr = buffer
173 + ctx->DrawBuffer->Ymin * ctx->DrawBuffer->Width
174 + ctx->DrawBuffer->Xmin;
175 for (j = 0; j < rows; j++) {
176 MEMSET( aptr, aclear, rowLen );
177 aptr += rowLen;
178 }
179 }
180 else {
181 /* clear whole buffer */
182 GLuint bytes = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height;
183 MEMSET( buffer, aclear, bytes );
184 }
185 }
186 }
187}
188
189
190
191void gl_write_alpha_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
192 CONST GLubyte rgba[][4], const GLubyte mask[] )
193{
194 GLubyte *aptr = ALPHA_DRAW_ADDR( x, y );
195 GLuint i;
196
197 if (mask) {
198 for (i=0;i<n;i++) {
199 if (mask[i]) {
200 *aptr = rgba[i][ACOMP];
201 }
202 aptr++;
203 }
204 }
205 else {
206 for (i=0;i<n;i++) {
207 *aptr++ = rgba[i][ACOMP];
208 }
209 }
210}
211
212
213void gl_write_mono_alpha_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
214 GLubyte alpha, const GLubyte mask[] )
215{
216 GLubyte *aptr = ALPHA_DRAW_ADDR( x, y );
217 GLuint i;
218
219 if (mask) {
220 for (i=0;i<n;i++) {
221 if (mask[i]) {
222 *aptr = alpha;
223 }
224 aptr++;
225 }
226 }
227 else {
228 for (i=0;i<n;i++) {
229 *aptr++ = alpha;
230 }
231 }
232}
233
234
235void gl_write_alpha_pixels( GLcontext *ctx,
236 GLuint n, const GLint x[], const GLint y[],
237 CONST GLubyte rgba[][4], const GLubyte mask[] )
238{
239 GLuint i;
240
241 if (mask) {
242 for (i=0;i<n;i++) {
243 if (mask[i]) {
244 GLubyte *aptr = ALPHA_DRAW_ADDR( x[i], y[i] );
245 *aptr = rgba[i][ACOMP];
246 }
247 }
248 }
249 else {
250 for (i=0;i<n;i++) {
251 GLubyte *aptr = ALPHA_DRAW_ADDR( x[i], y[i] );
252 *aptr = rgba[i][ACOMP];
253 }
254 }
255}
256
257
258void gl_write_mono_alpha_pixels( GLcontext *ctx,
259 GLuint n, const GLint x[], const GLint y[],
260 GLubyte alpha, const GLubyte mask[] )
261{
262 GLuint i;
263
264 if (mask) {
265 for (i=0;i<n;i++) {
266 if (mask[i]) {
267 GLubyte *aptr = ALPHA_DRAW_ADDR( x[i], y[i] );
268 *aptr = alpha;
269 }
270 }
271 }
272 else {
273 for (i=0;i<n;i++) {
274 GLubyte *aptr = ALPHA_DRAW_ADDR( x[i], y[i] );
275 *aptr = alpha;
276 }
277 }
278}
279
280
281
282void gl_read_alpha_span( GLcontext *ctx,
283 GLuint n, GLint x, GLint y, GLubyte rgba[][4] )
284{
285 GLubyte *aptr = ALPHA_READ_ADDR( x, y );
286 GLuint i;
287 for (i=0;i<n;i++) {
288 rgba[i][ACOMP] = *aptr++;
289 }
290}
291
292
293void gl_read_alpha_pixels( GLcontext *ctx,
294 GLuint n, const GLint x[], const GLint y[],
295 GLubyte rgba[][4], const GLubyte mask[] )
296{
297 GLuint i;
298 for (i=0;i<n;i++) {
299 if (mask[i]) {
300 GLubyte *aptr = ALPHA_READ_ADDR( x[i], y[i] );
301 rgba[i][ACOMP] = *aptr;
302 }
303 }
304}
305
306
307
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