lxdream 0.9.1| filename | src/drivers/gl_fbo.c |
| changeset | 1166:f405d42a9786 |
| prev | 1141:dc60a0987db9 |
| next | 1210:79bbd30363f4 |
| author | nkeynes |
| date | Fri Jan 28 16:14:57 2011 +1000 (13 years ago) |
| permissions | -rw-r--r-- |
| last change | Perform the sanity checks for FBOs and shaders up front rather than on every use, and remove surplus glGetError() calls |
| view | annotate | diff | log | raw |
1 /**
2 * $Id$
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 <stdlib.h>
28 #include "lxdream.h"
29 #include "display.h"
30 #include "drivers/video_gl.h"
31 #include "pvr2/glutil.h"
33 #ifdef HAVE_OPENGL_FBO
35 #define MAX_FRAMEBUFFERS 2
36 #define MAX_TEXTURES_PER_FB 16
38 static render_buffer_t gl_fbo_create_render_buffer( uint32_t width, uint32_t height, GLuint tex_id );
39 static void gl_fbo_destroy_render_buffer( render_buffer_t buffer );
40 static gboolean gl_fbo_set_render_target( render_buffer_t buffer );
41 static void gl_fbo_finish_render( render_buffer_t buffer );
42 static void gl_fbo_display_render_buffer( render_buffer_t buffer );
43 static void gl_fbo_load_frame_buffer( frame_buffer_t frame, render_buffer_t buffer );
44 static void gl_fbo_display_blank( uint32_t colour );
45 static gboolean gl_fbo_test_framebuffer( );
46 static gboolean gl_fbo_read_render_buffer( unsigned char *target, render_buffer_t buffer, int rowstride, int format );
48 extern uint32_t video_width, video_height;
50 /**
51 * Framebuffer info structure
52 */
53 struct gl_fbo_info {
54 GLuint fb_id;
55 GLuint depth_id;
56 GLuint stencil_id;
57 GLuint tex_ids[MAX_TEXTURES_PER_FB];
58 int width, height;
59 };
61 static GLint gl_fbo_max_attachments = 0;
62 static gboolean gl_fbo_have_packed_stencil = FALSE;
63 static struct gl_fbo_info fbo[MAX_FRAMEBUFFERS];
65 #define ATTACHMENT_POINT(n) (GL_COLOR_ATTACHMENT0_EXT+(n))
66 static int last_used_fbo;
68 gboolean gl_fbo_is_supported()
69 {
70 return isGLExtensionSupported("GL_EXT_framebuffer_object");
71 }
73 /**
74 * Construct the initial frame buffers and allocate ids for everything.
75 * The render handling driver methods are set to the fbo versions.
76 */
77 void gl_fbo_init( display_driver_t driver )
78 {
79 int i,j;
80 GLuint fbids[MAX_FRAMEBUFFERS];
81 GLuint rbids[MAX_FRAMEBUFFERS*2]; /* depth buffer, stencil buffer per fb */
83 glGetIntegerv(GL_MAX_COLOR_ATTACHMENTS_EXT, &gl_fbo_max_attachments);
84 glGenFramebuffersEXT( MAX_FRAMEBUFFERS, &fbids[0] );
85 glGenRenderbuffersEXT( MAX_FRAMEBUFFERS*2, &rbids[0] );
86 for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
87 fbo[i].fb_id = fbids[i];
88 fbo[i].depth_id = rbids[i*2];
89 fbo[i].stencil_id = rbids[i*2+1];
90 fbo[i].width = -1;
91 fbo[i].height = -1;
92 for( j=0; j<MAX_TEXTURES_PER_FB; j++ ) {
93 fbo[i].tex_ids[j] = -1;
94 }
95 }
96 last_used_fbo = 0;
98 if( isGLExtensionSupported("GL_EXT_packed_depth_stencil" ) ) {
99 driver->capabilities.stencil_bits = 8;
100 gl_fbo_have_packed_stencil = TRUE;
101 } else {
102 driver->capabilities.stencil_bits = 0;
103 gl_fbo_have_packed_stencil = FALSE;
104 WARN( "Packed depth stencil not available - disabling shadow volumes" );
105 }
107 driver->create_render_buffer = gl_fbo_create_render_buffer;
108 driver->destroy_render_buffer = gl_fbo_destroy_render_buffer;
109 driver->set_render_target = gl_fbo_set_render_target;
110 driver->finish_render = gl_fbo_finish_render;
111 driver->display_render_buffer = gl_fbo_display_render_buffer;
112 driver->load_frame_buffer = gl_fbo_load_frame_buffer;
113 driver->display_blank = gl_fbo_display_blank;
114 driver->read_render_buffer = gl_fbo_read_render_buffer;
116 gl_fbo_test_framebuffer();
117 glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
118 }
120 void gl_fbo_shutdown()
121 {
122 int i;
123 glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, 0 );
124 for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
125 glDeleteFramebuffersEXT( 1, &fbo[i].fb_id );
126 glDeleteRenderbuffersEXT( 2, &fbo[i].depth_id );
127 }
128 }
130 static void gl_fbo_setup_framebuffer( int bufno, int width, int height )
131 {
132 int i;
133 glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo[bufno].fb_id);
135 /* Clear out any existing texture attachments */
136 for( i=0; i<gl_fbo_max_attachments; i++ ) {
137 if( fbo[bufno].tex_ids[i] != -1 ) {
138 glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, ATTACHMENT_POINT(i),
139 GL_TEXTURE_RECTANGLE_ARB, 0, 0);
140 fbo[bufno].tex_ids[i] = -1;
141 }
142 }
144 /* Setup the renderbuffers */
145 if( gl_fbo_have_packed_stencil ) {
146 glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
147 glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH24_STENCIL8_EXT, width, height);
148 glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
149 GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
150 glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_STENCIL_ATTACHMENT_EXT,
151 GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
152 } else {
153 glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
154 glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT24, width, height);
155 glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
156 GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
157 /* In theory you could attach a separate stencil buffer. In practice this
158 * isn't actually supported by any hardware I've had access to, so we're
159 * stencil-less.
160 */
161 }
162 fbo[bufno].width = width;
163 fbo[bufno].height = height;
164 }
166 static int gl_fbo_get_framebuffer( int width, int height )
167 {
168 int bufno = -1, i;
169 /* find a compatible framebuffer context */
170 for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
171 if( fbo[i].width == -1 && bufno == -1 ) {
172 bufno = i;
173 } else if( fbo[i].width == width && fbo[i].height == height ) {
174 bufno = i;
175 break;
176 }
177 }
178 if( bufno == -1 ) {
179 bufno = last_used_fbo + 1;
180 if( bufno >= MAX_FRAMEBUFFERS ) {
181 bufno = 0;
182 }
183 last_used_fbo = bufno;
184 }
185 if( fbo[bufno].width == width && fbo[bufno].height == height ) {
186 glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, fbo[bufno].fb_id );
187 } else {
188 gl_fbo_setup_framebuffer( bufno, width, height );
189 }
190 return bufno;
191 }
193 /**
194 * Attach a texture to the framebuffer. The texture must already be initialized
195 * to the correct dimensions etc.
196 */
197 static GLint gl_fbo_attach_texture( int fbo_no, GLint tex_id ) {
198 int attach = -1, i;
199 for( i=0; i<gl_fbo_max_attachments; i++ ) {
200 if( fbo[fbo_no].tex_ids[i] == tex_id ) {
201 glDrawBuffer(ATTACHMENT_POINT(i));
202 glReadBuffer(ATTACHMENT_POINT(i));
203 return ATTACHMENT_POINT(i); // already attached
204 } else if( fbo[fbo_no].tex_ids[i] == -1 && attach == -1 ) {
205 attach = i;
206 }
207 }
208 if( attach == -1 ) {
209 attach = 0;
210 }
211 fbo[fbo_no].tex_ids[attach] = tex_id;
212 glBindTexture( GL_TEXTURE_RECTANGLE_ARB, 0 ); // Ensure the output texture is unbound
213 glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, ATTACHMENT_POINT(attach),
214 GL_TEXTURE_RECTANGLE_ARB, tex_id, 0 );
215 /* Set draw/read buffers by default */
216 glDrawBuffer(ATTACHMENT_POINT(attach));
217 glReadBuffer(ATTACHMENT_POINT(attach));
219 return ATTACHMENT_POINT(attach);
220 }
222 static gboolean gl_fbo_test_framebuffer( )
223 {
224 gboolean result = TRUE;
225 glGetError(); /* Clear error state just in case */
226 render_buffer_t buffer = gl_fbo_create_render_buffer( 640, 480, 0 );
227 gl_fbo_set_render_target(buffer);
229 GLint status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
230 if( status != GL_FRAMEBUFFER_COMPLETE_EXT ) {
231 ERROR( "Framebuffer failure: %x", status );
232 result = FALSE;
233 }
234 if( result ) {
235 result = gl_check_error( "Setting up framebuffer" );
236 }
238 gl_fbo_destroy_render_buffer( buffer );
239 return result;
240 }
242 static render_buffer_t gl_fbo_create_render_buffer( uint32_t width, uint32_t height, GLuint tex_id )
243 {
244 render_buffer_t buffer = calloc( sizeof(struct render_buffer), 1 );
245 buffer->width = width;
246 buffer->height = height;
247 buffer->tex_id = tex_id;
248 if( tex_id == 0 ) {
249 GLuint tex;
250 glGenTextures( 1, &tex );
251 buffer->buf_id = tex;
252 } else {
253 buffer->buf_id = tex_id;
254 glBindTexture( GL_TEXTURE_RECTANGLE_ARB, tex_id );
255 }
256 glBindTexture( GL_TEXTURE_RECTANGLE_ARB, buffer->buf_id );
257 glTexImage2D( GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL );
258 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_WRAP_S, GL_CLAMP );
259 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_WRAP_T, GL_CLAMP );
260 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
261 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
262 return buffer;
263 }
265 /**
266 * Ensure the texture in the given render buffer is not attached to a
267 * framebuffer (ie, so we can safely use it as a texture during the rendering
268 * cycle, or before deletion).
269 */
270 static void gl_fbo_detach_render_buffer( render_buffer_t buffer )
271 {
272 int i,j;
273 for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
274 if( fbo[i].width == buffer->width && fbo[i].height == buffer->height ) {
275 for( j=0; j<gl_fbo_max_attachments; j++ ) {
276 if( fbo[i].tex_ids[j] == buffer->buf_id ) {
277 glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo[i].fb_id);
278 glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, ATTACHMENT_POINT(j),
279 GL_TEXTURE_RECTANGLE_ARB, GL_NONE, 0 );
280 fbo[i].tex_ids[j] = -1;
281 return;
282 }
283 }
284 break;
285 }
286 }
287 }
289 static void gl_fbo_destroy_render_buffer( render_buffer_t buffer )
290 {
291 int i,j;
293 gl_fbo_detach_render_buffer( buffer );
295 if( buffer->buf_id != buffer->tex_id ) {
296 // If tex_id was set at buffer creation, we don't own the texture.
297 // Otherwise, delete it now.
298 GLuint tex = buffer->buf_id;
299 glDeleteTextures( 1, &tex );
300 }
301 buffer->buf_id = 0;
302 buffer->tex_id = 0;
303 free( buffer );
304 }
306 static gboolean gl_fbo_set_render_target( render_buffer_t buffer )
307 {
308 int fb = gl_fbo_get_framebuffer( buffer->width, buffer->height );
309 gl_fbo_attach_texture( fb, buffer->buf_id );
310 /* setup the gl context */
311 glViewport( 0, 0, buffer->width, buffer->height );
313 return TRUE;
314 }
316 static void gl_fbo_finish_render( render_buffer_t buffer )
317 {
318 glFinish();
319 gl_fbo_detach_render_buffer(buffer);
320 }
322 /**
323 * Render the texture holding the given buffer to the front window
324 * buffer.
325 */
326 static void gl_fbo_display_render_buffer( render_buffer_t buffer )
327 {
328 gl_fbo_detach();
329 gl_display_render_buffer( buffer );
330 }
332 static void gl_fbo_load_frame_buffer( frame_buffer_t frame, render_buffer_t buffer )
333 {
334 gl_fbo_detach();
335 gl_load_frame_buffer( frame, buffer->buf_id );
336 }
338 static void gl_fbo_display_blank( uint32_t colour )
339 {
340 gl_fbo_detach();
341 gl_display_blank( colour );
342 }
344 void gl_fbo_detach()
345 {
346 glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, 0 );
347 /* Make sure texture attachment is not a current draw/read buffer */
348 glDrawBuffer( GL_FRONT );
349 glReadBuffer( GL_FRONT );
350 display_driver->swap_buffers();
351 }
353 static gboolean gl_fbo_read_render_buffer( unsigned char *target, render_buffer_t buffer,
354 int rowstride, int format )
355 {
356 int fb = gl_fbo_get_framebuffer( buffer->width, buffer->height );
357 gl_fbo_attach_texture( fb, buffer->buf_id );
358 return gl_read_render_buffer( target, buffer, rowstride, format );
359 }
361 #else
362 gboolean gl_fbo_is_supported()
363 {
364 return FALSE;
365 }
367 void gl_fbo_init( display_driver_t driver )
368 {
369 }
371 #endif
.