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alphabuf.c
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1 /* $Id: alphabuf.c,v 1.5 1997/07/24 01:24:28 brianp Exp $ */
2 
3 /*
4  * Mesa 3-D graphics library
5  * Version: 2.4
6  * Copyright (C) 1995-1997 Brian Paul
7  *
8  * This library is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Library General Public
10  * License as published by the Free Software Foundation; either
11  * version 2 of the License, or (at your option) any later version.
12  *
13  * This library is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Library General Public License for more details.
17  *
18  * You should have received a copy of the GNU Library General Public
19  * License along with this library; if not, write to the Free
20  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21  */
22 
23 
24 /*
25  * $Log: alphabuf.c,v $
26  * Revision 1.5 1997/07/24 01:24:28 brianp
27  * changed precompiled header symbol from PCH to PC_HEADER
28  *
29  * Revision 1.4 1997/05/28 03:23:09 brianp
30  * added precompiled header (PCH) support
31  *
32  * Revision 1.3 1996/10/02 02:51:07 brianp
33  * in gl_clear_alpha_buffers() check for GL_FRONT_AND_BACK draw mode
34  *
35  * Revision 1.2 1996/09/15 14:15:54 brianp
36  * now use GLframebuffer and GLvisual
37  *
38  * Revision 1.1 1996/09/13 01:38:16 brianp
39  * Initial revision
40  *
41  */
42 
43 
44 
45 /*
46  * Software alpha planes. Many frame buffers don't have alpha bits so
47  * we simulate them in software.
48  */
49 
50 
51 #ifdef PC_HEADER
52 #include "all.h"
53 #else
54 #include <stdlib.h>
55 #include <string.h>
56 #include "alphabuf.h"
57 #include "context.h"
58 #include "macros.h"
59 #include "types.h"
60 #endif
61 
62 
63 
64 #define ALPHA_ADDR(X,Y) (ctx->Buffer->Alpha + (Y) * ctx->Buffer->Width + (X))
65 
66 
67 
68 /*
69  * Allocate a new front and back alpha buffer.
70  */
72 {
73  GLint bytes = ctx->Buffer->Width * ctx->Buffer->Height * sizeof(GLubyte);
74 
75  if (ctx->Visual->FrontAlphaEnabled) {
76  if (ctx->Buffer->FrontAlpha) {
77  free( ctx->Buffer->FrontAlpha );
78  }
79  ctx->Buffer->FrontAlpha = (GLubyte *) malloc( bytes );
80  if (!ctx->Buffer->FrontAlpha) {
81  /* out of memory */
82  gl_error( ctx, GL_OUT_OF_MEMORY, "Couldn't allocate front alpha buffer" );
83  }
84  }
85  if (ctx->Visual->BackAlphaEnabled) {
86  if (ctx->Buffer->BackAlpha) {
87  free( ctx->Buffer->BackAlpha );
88  }
89  ctx->Buffer->BackAlpha = (GLubyte *) malloc( bytes );
90  if (!ctx->Buffer->BackAlpha) {
91  /* out of memory */
92  gl_error( ctx, GL_OUT_OF_MEMORY, "Couldn't allocate back alpha buffer" );
93  }
94  }
95  if (ctx->Color.DrawBuffer==GL_FRONT) {
96  ctx->Buffer->Alpha = ctx->Buffer->FrontAlpha;
97  }
98  if (ctx->Color.DrawBuffer==GL_BACK) {
99  ctx->Buffer->Alpha = ctx->Buffer->BackAlpha;
100  }
101 }
102 
103 
104 
105 /*
106  * Clear the front and/or back alpha planes.
107  */
109 {
110  GLint buffer;
111 
112  /* Loop over front and back buffers */
113  for (buffer=0;buffer<2;buffer++) {
114 
115  /* Get pointer to front or back buffer */
116  GLubyte *abuffer = NULL;
117  if (buffer==0
118  && ( ctx->Color.DrawBuffer==GL_FRONT
119  || ctx->Color.DrawBuffer==GL_FRONT_AND_BACK)
120  && ctx->Visual->FrontAlphaEnabled && ctx->Buffer->FrontAlpha) {
121  abuffer = ctx->Buffer->FrontAlpha;
122  }
123  else if (buffer==1
124  && ( ctx->Color.DrawBuffer==GL_BACK
125  || ctx->Color.DrawBuffer==GL_FRONT_AND_BACK)
126  && ctx->Visual->BackAlphaEnabled && ctx->Buffer->BackAlpha) {
127  abuffer = ctx->Buffer->BackAlpha;
128  }
129 
130  /* Clear the alpha buffer */
131  if (abuffer) {
132  GLubyte aclear = (GLint) (ctx->Color.ClearColor[3]
133  * ctx->Visual->AlphaScale);
134  if (ctx->Scissor.Enabled) {
135  /* clear scissor region */
136  GLint i, j;
137  for (j=0;j<ctx->Scissor.Height;j++) {
138  GLubyte *aptr = ALPHA_ADDR(ctx->Buffer->Xmin,
139  ctx->Buffer->Ymin+j);
140  for (i=0;i<ctx->Scissor.Width;i++) {
141  *aptr++ = aclear;
142  }
143  }
144  }
145  else {
146  /* clear whole buffer */
147  MEMSET( abuffer, aclear, ctx->Buffer->Width*ctx->Buffer->Height );
148  }
149  }
150  }
151 }
152 
153 
154 
156  GLubyte alpha[], GLubyte mask[] )
157 {
158  GLubyte *aptr = ALPHA_ADDR( x, y );
159  GLuint i;
160 
161  if (mask) {
162  for (i=0;i<n;i++) {
163  if (mask[i]) {
164  *aptr = alpha[i];
165  }
166  aptr++;
167  }
168  }
169  else {
170  for (i=0;i<n;i++) {
171  *aptr++ = alpha[i];
172  }
173  }
174 }
175 
176 
179 {
180  GLubyte *aptr = ALPHA_ADDR( x, y );
181  GLuint i;
182 
183  if (mask) {
184  for (i=0;i<n;i++) {
185  if (mask[i]) {
186  *aptr = alpha;
187  }
188  aptr++;
189  }
190  }
191  else {
192  for (i=0;i<n;i++) {
193  *aptr++ = alpha;
194  }
195  }
196 }
197 
198 
200  GLuint n, const GLint x[], const GLint y[],
201  const GLubyte alpha[], const GLubyte mask[] )
202 {
203  GLuint i;
204 
205  if (mask) {
206  for (i=0;i<n;i++) {
207  if (mask[i]) {
208  GLubyte *aptr = ALPHA_ADDR( x[i], y[i] );
209  *aptr = alpha[i];
210  }
211  }
212  }
213  else {
214  for (i=0;i<n;i++) {
215  GLubyte *aptr = ALPHA_ADDR( x[i], y[i] );
216  *aptr = alpha[i];
217  }
218  }
219 }
220 
221 
223  GLuint n, const GLint x[], const GLint y[],
224  GLubyte alpha, const GLubyte mask[] )
225 {
226  GLuint i;
227 
228  if (mask) {
229  for (i=0;i<n;i++) {
230  if (mask[i]) {
231  GLubyte *aptr = ALPHA_ADDR( x[i], y[i] );
232  *aptr = alpha;
233  }
234  }
235  }
236  else {
237  for (i=0;i<n;i++) {
238  GLubyte *aptr = ALPHA_ADDR( x[i], y[i] );
239  *aptr = alpha;
240  }
241  }
242 }
243 
244 
245 
247  GLuint n, GLint x, GLint y, GLubyte alpha[] )
248 {
249  GLubyte *aptr = ALPHA_ADDR( x, y );
250  GLuint i;
251  for (i=0;i<n;i++) {
252  alpha[i] = *aptr++;
253  }
254 }
255 
256 
258  GLuint n, const GLint x[], const GLint y[],
259  GLubyte alpha[], const GLubyte mask[] )
260 {
261  GLuint i;
262  for (i=0;i<n;i++) {
263  if (mask[i]) {
264  GLubyte *aptr = ALPHA_ADDR( x[i], y[i] );
265  alpha[i] = *aptr;
266  }
267  }
268 }
269 
270 
271 
GLboolean BackAlphaEnabled
Definition: types.h:1166
#define GL_BACK
Definition: gl.h:271
GLboolean FrontAlphaEnabled
Definition: types.h:1165
#define MEMSET(DST, VAL, N)
Definition: macros.h:241
GLframebuffer * Buffer
Definition: types.h:1273
unsigned char GLubyte
Definition: gl.h:157
GLint Ymin
Definition: types.h:1195
#define free
Definition: debug_ros.c:5
GLdouble n
Definition: glext.h:7729
GLuint buffer
Definition: glext.h:5915
GLint GLint GLint GLint GLint x
Definition: gl.h:1548
GLvisual * Visual
Definition: types.h:1272
void gl_read_alpha_span(GLcontext *ctx, GLuint n, GLint x, GLint y, GLubyte alpha[])
Definition: alphabuf.c:246
GLint Height
Definition: types.h:1179
#define GL_FRONT_AND_BACK
Definition: gl.h:336
GLsizei GLenum const GLvoid GLsizei GLenum GLbyte GLbyte GLbyte GLdouble GLdouble GLdouble GLfloat GLfloat GLfloat GLint GLint GLint GLshort GLshort GLshort GLubyte GLubyte GLubyte GLuint GLuint GLuint GLushort GLushort GLushort GLbyte GLbyte GLbyte GLbyte GLdouble GLdouble GLdouble GLdouble GLfloat GLfloat GLfloat GLfloat GLint GLint GLint GLint GLshort GLshort GLshort GLshort GLubyte GLubyte GLubyte GLubyte GLuint GLuint GLuint GLuint GLushort GLushort GLushort GLushort GLboolean const GLdouble const GLfloat const GLint const GLshort const GLbyte const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLdouble const GLfloat const GLfloat const GLint const GLint const GLshort const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort GLenum GLenum GLenum GLfloat GLenum GLint GLenum GLenum GLenum GLfloat GLenum GLenum GLint GLenum GLfloat GLenum GLint GLint GLushort GLenum GLenum GLfloat GLenum GLenum GLint GLfloat const GLubyte GLenum GLenum GLenum const GLfloat GLenum GLenum const GLint GLenum GLint GLint GLsizei GLsizei GLint GLenum GLenum const GLvoid GLenum GLenum const GLfloat GLenum GLenum const GLint GLenum GLenum const GLdouble GLenum GLenum const GLfloat GLenum GLenum const GLint GLsizei GLuint GLfloat GLuint GLbitfield GLfloat GLint GLuint GLboolean GLenum GLfloat GLenum GLbitfield GLenum GLfloat GLfloat GLint GLint const GLfloat GLenum GLfloat GLfloat GLint GLint GLfloat GLfloat GLint GLint const GLfloat GLint GLfloat GLfloat GLint GLfloat GLfloat GLint GLfloat GLfloat const GLdouble const GLfloat const GLdouble const GLfloat GLint i
Definition: glfuncs.h:248
GLenum GLint GLuint mask
Definition: glext.h:6028
static unsigned char bytes[4]
Definition: adnsresfilter.c:74
void gl_clear_alpha_buffers(GLcontext *ctx)
Definition: alphabuf.c:108
#define GL_FRONT
Definition: gl.h:270
smooth NULL
Definition: ftsmooth.c:416
GLfloat AlphaScale
Definition: types.h:1143
GLint Xmin
Definition: types.h:1195
struct gl_colorbuffer_attrib Color
Definition: types.h:1319
GLsizei GLenum const GLvoid GLsizei GLenum GLbyte GLbyte GLbyte GLdouble GLdouble GLdouble GLfloat GLfloat GLfloat GLint GLint GLint GLshort GLshort GLshort GLubyte GLubyte GLubyte GLuint GLuint GLuint GLushort GLushort GLushort GLbyte GLbyte GLbyte GLbyte GLdouble GLdouble GLdouble GLdouble GLfloat GLfloat GLfloat GLfloat GLint GLint GLint GLint GLshort GLshort GLshort GLshort GLubyte GLubyte GLubyte GLubyte GLuint GLuint GLuint GLuint GLushort GLushort GLushort GLushort GLboolean const GLdouble const GLfloat const GLint const GLshort const GLbyte const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLdouble const GLfloat const GLfloat const GLint const GLint const GLshort const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort GLenum GLenum GLenum GLfloat GLenum GLint GLenum GLenum GLenum GLfloat GLenum GLenum GLint GLenum GLfloat GLenum GLint GLint GLushort GLenum GLenum GLfloat GLenum GLenum GLint GLfloat const GLubyte GLenum GLenum GLenum const GLfloat GLenum GLenum const GLint GLenum GLint GLint GLsizei GLsizei GLint GLenum GLenum const GLvoid GLenum GLenum const GLfloat GLenum GLenum const GLint GLenum GLenum const GLdouble GLenum GLenum const GLfloat GLenum GLenum const GLint GLsizei GLuint GLfloat GLuint GLbitfield GLfloat GLint GLuint GLboolean GLenum GLfloat GLenum GLbitfield GLenum GLfloat GLfloat GLint GLint const GLfloat GLenum GLfloat GLfloat GLint GLint GLfloat GLfloat GLint GLint const GLfloat GLint GLfloat GLfloat GLint GLfloat GLfloat GLint GLfloat GLfloat const GLdouble const GLfloat const GLdouble const GLfloat GLint GLint GLint j
Definition: glfuncs.h:250
struct gl_scissor_attrib Scissor
Definition: types.h:1332
#define ALPHA_ADDR(X, Y)
Definition: alphabuf.c:64
void gl_read_alpha_pixels(GLcontext *ctx, GLuint n, const GLint x[], const GLint y[], GLubyte alpha[], const GLubyte mask[])
Definition: alphabuf.c:257
void gl_write_alpha_span(GLcontext *ctx, GLuint n, GLint x, GLint y, GLubyte alpha[], GLubyte mask[])
Definition: alphabuf.c:155
GLubyte * Alpha
Definition: types.h:1192
void gl_error(GLcontext *ctx, GLenum error, const char *s)
Definition: context.c:1421
GLubyte * BackAlpha
Definition: types.h:1191
unsigned int GLuint
Definition: gl.h:159
void gl_write_mono_alpha_span(GLcontext *ctx, GLuint n, GLint x, GLint y, GLubyte alpha, GLubyte mask[])
Definition: alphabuf.c:177
GLint GLint GLint GLint GLint GLint y
Definition: gl.h:1548
GLint Width
Definition: types.h:1178
#define GL_OUT_OF_MEMORY
Definition: gl.h:699
GLclampf GLclampf GLclampf alpha
Definition: gl.h:1740
int GLint
Definition: gl.h:156
#define malloc
Definition: debug_ros.c:4
void gl_write_alpha_pixels(GLcontext *ctx, GLuint n, const GLint x[], const GLint y[], const GLubyte alpha[], const GLubyte mask[])
Definition: alphabuf.c:199
void gl_alloc_alpha_buffers(GLcontext *ctx)
Definition: alphabuf.c:71
GLubyte * FrontAlpha
Definition: types.h:1190
void gl_write_mono_alpha_pixels(GLcontext *ctx, GLuint n, const GLint x[], const GLint y[], GLubyte alpha, const GLubyte mask[])
Definition: alphabuf.c:222