lxdream 0.9.1| filename | src/drivers/gl_fbo.c |
| changeset | 443:1163eb5c0590 |
| prev | 438:f4d7774967d1 |
| next | 445:75c668cdfdc0 |
| author | nkeynes |
| date | Sat Oct 13 04:01:02 2007 +0000 (16 years ago) |
| permissions | -rw-r--r-- |
| last change | Add ability to track the last displayed buffer, and handle expose/resize events appropriately |
| view | annotate | diff | log | raw |
1 /**
2 * $Id: gl_fbo.c,v 1.5 2007-10-13 04:01:02 nkeynes Exp $
3 *
4 * GL framebuffer-based driver shell. This requires the EXT_framebuffer_object
5 * extension, but is much nicer/faster/etc than pbuffers when it's available.
6 * This is (optionally) used indirectly by the top-level GLX driver.
7 *
8 * Strategy-wise, we maintain 2 framebuffers with up to 4 target colour
9 * buffers a piece. Effectively this reserves one fb for display output,
10 * and the other for texture output (each fb has a single size).
11 *
12 * Copyright (c) 2005 Nathan Keynes.
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 */
25 #define GL_GLEXT_PROTOTYPES 1
27 #include <GL/gl.h>
28 #include <GL/glext.h>
29 #include "display.h"
30 #include "drivers/video_x11.h"
31 #include "drivers/gl_common.h"
33 #define MAX_FRAMEBUFFERS 2
34 #define MAX_TEXTURES_PER_FB 4
36 static render_buffer_t gl_fbo_create_render_buffer( uint32_t width, uint32_t height );
37 static void gl_fbo_destroy_render_buffer( render_buffer_t buffer );
38 static gboolean gl_fbo_set_render_target( render_buffer_t buffer );
39 static gboolean gl_fbo_display_render_buffer( render_buffer_t buffer );
40 static gboolean gl_fbo_display_frame_buffer( frame_buffer_t buffer );
41 static gboolean gl_fbo_display_blank( uint32_t colour );
42 static gboolean gl_fbo_read_render_buffer( render_buffer_t buffer, unsigned char *target );
44 extern uint32_t video_width, video_height;
46 /**
47 * Framebuffer info structure
48 */
49 struct gl_fbo_info {
50 GLuint fb_id;
51 GLuint depth_id;
52 GLuint stencil_id;
53 GLuint tex_ids[MAX_TEXTURES_PER_FB];
54 int width, height;
55 };
57 static struct gl_fbo_info fbo[MAX_FRAMEBUFFERS];
58 const static int ATTACHMENT_POINTS[MAX_TEXTURES_PER_FB] = {
59 GL_COLOR_ATTACHMENT0_EXT, GL_COLOR_ATTACHMENT1_EXT,
60 GL_COLOR_ATTACHMENT2_EXT, GL_COLOR_ATTACHMENT3_EXT };
61 static int last_used_fbo;
63 gboolean gl_fbo_is_supported()
64 {
65 return isGLExtensionSupported("GL_EXT_framebuffer_object");
66 }
68 /**
69 * Construct the initial frame buffers and allocate ids for everything.
70 * The render handling driver methods are set to the fbo versions.
71 */
72 void gl_fbo_init( display_driver_t driver )
73 {
74 int i,j;
75 GLuint fbids[MAX_FRAMEBUFFERS];
76 GLuint rbids[MAX_FRAMEBUFFERS*2]; /* depth buffer, stencil buffer per fb */
78 glGenFramebuffersEXT( MAX_FRAMEBUFFERS, &fbids[0] );
79 glGenRenderbuffersEXT( MAX_FRAMEBUFFERS*2, &rbids[0] );
80 for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
81 fbo[i].fb_id = fbids[i];
82 fbo[i].depth_id = rbids[i*2];
83 fbo[i].stencil_id = rbids[i*2+1];
84 fbo[i].width = -1;
85 fbo[i].height = -1;
86 for( j=0; j<MAX_TEXTURES_PER_FB; j++ ) {
87 fbo[i].tex_ids[j] = -1;
88 }
89 }
90 last_used_fbo = 0;
92 driver->create_render_buffer = gl_fbo_create_render_buffer;
93 driver->destroy_render_buffer = gl_fbo_destroy_render_buffer;
94 driver->set_render_target = gl_fbo_set_render_target;
95 driver->display_render_buffer = gl_fbo_display_render_buffer;
96 driver->display_frame_buffer = gl_fbo_display_frame_buffer;
97 driver->display_blank = gl_fbo_display_blank;
98 driver->read_render_buffer = gl_fbo_read_render_buffer;
99 }
101 void gl_fbo_shutdown()
102 {
103 int i;
104 glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, 0 );
105 for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
106 glDeleteFramebuffersEXT( 1, &fbo[i].fb_id );
107 glDeleteRenderbuffersEXT( 2, &fbo[i].depth_id );
108 }
109 }
111 void gl_fbo_setup_framebuffer( int bufno, int width, int height )
112 {
113 glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo[bufno].fb_id);
114 glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
115 glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT24, width, height);
116 glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
117 GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
118 /* Stencil doesn't work on ATI, and we're not using it at the moment anyway, so...
119 glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fbo[bufno].stencil_id);
120 glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_STENCIL_INDEX, width, height);
121 glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_STENCIL_ATTACHMENT_EXT,
122 GL_RENDERBUFFER_EXT, fbo[bufno].stencil_id);
123 */
124 fbo[bufno].width = width;
125 fbo[bufno].height = height;
126 }
128 int gl_fbo_get_framebuffer( int width, int height )
129 {
130 int bufno = -1, i;
131 /* find a compatible framebuffer context */
132 for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
133 if( fbo[i].width == -1 && bufno == -1 ) {
134 bufno = i;
135 } else if( fbo[i].width == width && fbo[i].height == height ) {
136 bufno = i;
137 break;
138 }
139 }
140 if( bufno == -1 ) {
141 bufno = last_used_fbo + 1;
142 if( bufno > MAX_FRAMEBUFFERS ) {
143 bufno = 0;
144 }
145 last_used_fbo = bufno;
146 }
147 if( fbo[bufno].width == width && fbo[bufno].height == height ) {
148 glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, fbo[bufno].fb_id );
149 } else {
150 gl_fbo_setup_framebuffer( bufno, width, height );
151 }
152 return bufno;
153 }
155 /**
156 * Attach a texture to the framebuffer. The texture must already be initialized
157 * to the correct dimensions etc.
158 */
159 static GLint gl_fbo_attach_texture( int fbo_no, GLint tex_id ) {
160 int attach = -1, i;
161 for( i=0; i<MAX_TEXTURES_PER_FB; i++ ) {
162 if( fbo[fbo_no].tex_ids[i] == tex_id ) {
163 glDrawBuffer(ATTACHMENT_POINTS[i]);
164 glReadBuffer(ATTACHMENT_POINTS[i]);
165 return ATTACHMENT_POINTS[i]; // already attached
166 } else if( fbo[fbo_no].tex_ids[i] == -1 && attach == -1 ) {
167 attach = i;
168 }
169 }
170 if( attach == -1 ) {
171 /* should never happen */
172 attach = 0;
173 }
174 fbo[fbo_no].tex_ids[attach] = tex_id;
175 glBindTexture( GL_TEXTURE_RECTANGLE_ARB, 0 ); // Ensure the output texture is unbound
176 glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, ATTACHMENT_POINTS[attach],
177 GL_TEXTURE_RECTANGLE_ARB, tex_id, 0 );
178 /* Set draw/read buffers by default */
179 glDrawBuffer(ATTACHMENT_POINTS[attach]);
180 glReadBuffer(ATTACHMENT_POINTS[attach]);
183 GLint status = glGetError();
184 if( status != GL_NO_ERROR ) {
185 ERROR( "GL error setting render target (%x)!", status );
186 }
187 status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
188 if( status != GL_FRAMEBUFFER_COMPLETE_EXT ) {
189 ERROR( "Framebuffer failure: %x", status );
190 exit(1);
191 }
193 return ATTACHMENT_POINTS[attach];
194 }
196 static render_buffer_t gl_fbo_create_render_buffer( uint32_t width, uint32_t height )
197 {
198 render_buffer_t buffer = calloc( sizeof(struct render_buffer), 1 );
199 buffer->width = width;
200 buffer->height = height;
201 glGenTextures( 1, &buffer->buf_id );
202 glBindTexture( GL_TEXTURE_RECTANGLE_ARB, buffer->buf_id );
203 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_WRAP_S, GL_CLAMP );
204 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_WRAP_T, GL_CLAMP );
205 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
206 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
207 glTexImage2D( GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL );
208 return buffer;
209 }
211 static void gl_fbo_destroy_render_buffer( render_buffer_t buffer )
212 {
213 int i,j;
214 for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
215 for( j=0; j < MAX_TEXTURES_PER_FB; j++ ) {
216 if( fbo[i].tex_ids[j] == buffer->buf_id ) {
217 glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, ATTACHMENT_POINTS[j],
218 GL_TEXTURE_RECTANGLE_ARB, GL_NONE, 0 );
219 fbo[i].tex_ids[j] = -1;
220 }
221 }
222 }
224 glDeleteTextures( 1, &buffer->buf_id );
225 buffer->buf_id = 0;
226 free( buffer );
227 }
229 static gboolean gl_fbo_set_render_target( render_buffer_t buffer )
230 {
231 glGetError();
232 int fb = gl_fbo_get_framebuffer( buffer->width, buffer->height );
233 gl_fbo_attach_texture( fb, buffer->buf_id );
234 /* setup the gl context */
235 glViewport( 0, 0, buffer->width, buffer->height );
237 return TRUE;
238 }
240 /**
241 * Render the texture holding the given buffer to the front window
242 * buffer.
243 */
244 static gboolean gl_fbo_display_render_buffer( render_buffer_t buffer )
245 {
246 glFinish();
247 glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, 0 ); // real window
248 glDrawBuffer( GL_FRONT );
249 glReadBuffer( GL_FRONT );
250 gl_display_tex_rectangle( buffer->buf_id, buffer->width, buffer->height, TRUE );
251 /*
252 glViewport( 0, 0, video_width, video_height );
253 glEnable( GL_TEXTURE_RECTANGLE_ARB );
254 glBindTexture( GL_TEXTURE_RECTANGLE_ARB, buffer->buf_id );
255 glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE );
256 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
257 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
258 glDisable( GL_ALPHA_TEST );
259 glDisable( GL_DEPTH_TEST );
260 glDisable( GL_SCISSOR_TEST );
261 glDisable( GL_CULL_FACE );
263 glMatrixMode(GL_PROJECTION);
264 glLoadIdentity();
265 glOrtho( 0, buffer->width, buffer->height, 0, 0, -65535 );
266 glMatrixMode(GL_MODELVIEW);
267 glLoadIdentity();
268 glEnable( GL_BLEND );
269 glBlendFunc( GL_ONE, GL_ZERO );
270 glDisable( GL_DEPTH_TEST );
271 glBegin( GL_QUADS );
272 glTexCoord2i( 0.5, buffer->height-0.5 );
273 glVertex2f( 0.0, 0.0 );
274 glTexCoord2i( buffer->width-0.5, buffer->height-0.5 );
275 glVertex2f( buffer->width, 0.0 );
276 glTexCoord2i( buffer->width-0.5, 0 );
277 glVertex2f( buffer->width, buffer->height );
278 glTexCoord2i( 0.5, 0.5 );
279 glVertex2f( 0.0, buffer->height );
280 glEnd();
281 glDisable( GL_TEXTURE_RECTANGLE_ARB );
282 glFlush();
283 */
284 return TRUE;
285 }
287 static gboolean gl_fbo_display_frame_buffer( frame_buffer_t buffer )
288 {
289 glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, 0 );
290 glDrawBuffer( GL_FRONT );
291 glReadBuffer( GL_FRONT );
292 return gl_display_frame_buffer( buffer );
293 }
295 static gboolean gl_fbo_display_blank( uint32_t colour )
296 {
297 glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, 0 );
298 glDrawBuffer( GL_FRONT );
299 glReadBuffer( GL_FRONT );
300 return gl_display_blank( colour );
301 }
303 static gboolean gl_fbo_read_render_buffer( render_buffer_t buffer, unsigned char *target )
304 {
305 int fb = gl_fbo_get_framebuffer( buffer->width, buffer->height );
306 gl_fbo_attach_texture( fb, buffer->buf_id );
307 return gl_read_render_buffer( buffer, target );
308 }
.