filename | src/drivers/gl_fbo.c |
changeset | 1076:18c164e8aec4 |
prev | 877:8331f4aa3616 |
next | 1141:dc60a0987db9 |
author | nkeynes |
date | Mon Aug 03 08:41:11 2009 +1000 (14 years ago) |
permissions | -rw-r--r-- |
last change | Rearrange frame output slightly. pvr2_display_frame renamed to pvr2_next_frame and changed to update the frame data without displaying it. pvr2_redraw_display renamed to pvr2_draw_frame, called internally after pvr2_next_frame Add swap_buffers() method to the display driver Remove explicit glDrawBuffer() calls where they're referencing the window. pvr2_draw_frame now gets to decide where to draw. Add force_vsync flag to force double-buffering (not configurable yet) |
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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_read_render_buffer( unsigned char *target, render_buffer_t buffer, int rowstride, int format );
47 extern uint32_t video_width, video_height;
49 /**
50 * Framebuffer info structure
51 */
52 struct gl_fbo_info {
53 GLuint fb_id;
54 GLuint depth_id;
55 GLuint stencil_id;
56 GLuint tex_ids[MAX_TEXTURES_PER_FB];
57 int width, height;
58 };
60 static GLint gl_fbo_max_attachments = 0;
61 static gboolean gl_fbo_have_packed_stencil = FALSE;
62 static struct gl_fbo_info fbo[MAX_FRAMEBUFFERS];
64 #define ATTACHMENT_POINT(n) (GL_COLOR_ATTACHMENT0_EXT+(n))
65 static int last_used_fbo;
67 gboolean gl_fbo_is_supported()
68 {
69 return isGLExtensionSupported("GL_EXT_framebuffer_object");
70 }
72 /**
73 * Construct the initial frame buffers and allocate ids for everything.
74 * The render handling driver methods are set to the fbo versions.
75 */
76 void gl_fbo_init( display_driver_t driver )
77 {
78 int i,j;
79 GLuint fbids[MAX_FRAMEBUFFERS];
80 GLuint rbids[MAX_FRAMEBUFFERS*2]; /* depth buffer, stencil buffer per fb */
82 glGetIntegerv(GL_MAX_COLOR_ATTACHMENTS_EXT, &gl_fbo_max_attachments);
83 glGenFramebuffersEXT( MAX_FRAMEBUFFERS, &fbids[0] );
84 glGenRenderbuffersEXT( MAX_FRAMEBUFFERS*2, &rbids[0] );
85 for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
86 fbo[i].fb_id = fbids[i];
87 fbo[i].depth_id = rbids[i*2];
88 fbo[i].stencil_id = rbids[i*2+1];
89 fbo[i].width = -1;
90 fbo[i].height = -1;
91 for( j=0; j<MAX_TEXTURES_PER_FB; j++ ) {
92 fbo[i].tex_ids[j] = -1;
93 }
94 }
95 last_used_fbo = 0;
97 if( isGLExtensionSupported("GL_EXT_packed_depth_stencil" ) ) {
98 driver->capabilities.stencil_bits = 8;
99 gl_fbo_have_packed_stencil = TRUE;
100 } else {
101 driver->capabilities.stencil_bits = 0;
102 gl_fbo_have_packed_stencil = FALSE;
103 WARN( "Packed depth stencil not available - disabling shadow volumes" );
104 }
106 driver->create_render_buffer = gl_fbo_create_render_buffer;
107 driver->destroy_render_buffer = gl_fbo_destroy_render_buffer;
108 driver->set_render_target = gl_fbo_set_render_target;
109 driver->finish_render = gl_fbo_finish_render;
110 driver->display_render_buffer = gl_fbo_display_render_buffer;
111 driver->load_frame_buffer = gl_fbo_load_frame_buffer;
112 driver->display_blank = gl_fbo_display_blank;
113 driver->read_render_buffer = gl_fbo_read_render_buffer;
115 glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
116 }
118 void gl_fbo_shutdown()
119 {
120 int i;
121 glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, 0 );
122 for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
123 glDeleteFramebuffersEXT( 1, &fbo[i].fb_id );
124 glDeleteRenderbuffersEXT( 2, &fbo[i].depth_id );
125 }
126 }
128 static void gl_fbo_setup_framebuffer( int bufno, int width, int height )
129 {
130 int i;
131 glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo[bufno].fb_id);
133 /* Clear out any existing texture attachments */
134 for( i=0; i<gl_fbo_max_attachments; i++ ) {
135 if( fbo[bufno].tex_ids[i] != -1 ) {
136 glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, ATTACHMENT_POINT(i),
137 GL_TEXTURE_RECTANGLE_ARB, 0, 0);
138 fbo[bufno].tex_ids[i] = -1;
139 }
140 }
142 /* Setup the renderbuffers */
143 if( gl_fbo_have_packed_stencil ) {
144 glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
145 glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH24_STENCIL8_EXT, width, height);
146 glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
147 GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
148 glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_STENCIL_ATTACHMENT_EXT,
149 GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
150 } else {
151 glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
152 glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT24, width, height);
153 glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
154 GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
155 /* In theory you could attach a separate stencil buffer. In practice this
156 * isn't actually supported by any hardware I've had access to, so we're
157 * stencil-less.
158 */
159 }
160 fbo[bufno].width = width;
161 fbo[bufno].height = height;
162 }
164 static int gl_fbo_get_framebuffer( int width, int height )
165 {
166 int bufno = -1, i;
167 /* find a compatible framebuffer context */
168 for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
169 if( fbo[i].width == -1 && bufno == -1 ) {
170 bufno = i;
171 } else if( fbo[i].width == width && fbo[i].height == height ) {
172 bufno = i;
173 break;
174 }
175 }
176 if( bufno == -1 ) {
177 bufno = last_used_fbo + 1;
178 if( bufno >= MAX_FRAMEBUFFERS ) {
179 bufno = 0;
180 }
181 last_used_fbo = bufno;
182 }
183 if( fbo[bufno].width == width && fbo[bufno].height == height ) {
184 glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, fbo[bufno].fb_id );
185 } else {
186 gl_fbo_setup_framebuffer( bufno, width, height );
187 }
188 return bufno;
189 }
191 /**
192 * Attach a texture to the framebuffer. The texture must already be initialized
193 * to the correct dimensions etc.
194 */
195 static GLint gl_fbo_attach_texture( int fbo_no, GLint tex_id ) {
196 int attach = -1, i;
197 for( i=0; i<gl_fbo_max_attachments; i++ ) {
198 if( fbo[fbo_no].tex_ids[i] == tex_id ) {
199 glDrawBuffer(ATTACHMENT_POINT(i));
200 glReadBuffer(ATTACHMENT_POINT(i));
201 return ATTACHMENT_POINT(i); // already attached
202 } else if( fbo[fbo_no].tex_ids[i] == -1 && attach == -1 ) {
203 attach = i;
204 }
205 }
206 if( attach == -1 ) {
207 attach = 0;
208 }
209 fbo[fbo_no].tex_ids[attach] = tex_id;
210 glBindTexture( GL_TEXTURE_RECTANGLE_ARB, 0 ); // Ensure the output texture is unbound
211 glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, ATTACHMENT_POINT(attach),
212 GL_TEXTURE_RECTANGLE_ARB, tex_id, 0 );
213 /* Set draw/read buffers by default */
214 glDrawBuffer(ATTACHMENT_POINT(attach));
215 glReadBuffer(ATTACHMENT_POINT(attach));
218 GLint status = glGetError();
219 if( status != GL_NO_ERROR ) {
220 ERROR( "GL error setting render target (%x)!", status );
221 }
222 status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
223 if( status != GL_FRAMEBUFFER_COMPLETE_EXT ) {
224 ERROR( "Framebuffer failure: %x", status );
225 exit(1);
226 }
228 return ATTACHMENT_POINT(attach);
229 }
231 static render_buffer_t gl_fbo_create_render_buffer( uint32_t width, uint32_t height, GLuint tex_id )
232 {
233 render_buffer_t buffer = calloc( sizeof(struct render_buffer), 1 );
234 buffer->width = width;
235 buffer->height = height;
236 buffer->tex_id = tex_id;
237 if( tex_id == 0 ) {
238 GLuint tex;
239 glGenTextures( 1, &tex );
240 buffer->buf_id = tex;
241 } else {
242 buffer->buf_id = tex_id;
243 glBindTexture( GL_TEXTURE_RECTANGLE_ARB, tex_id );
244 }
245 glBindTexture( GL_TEXTURE_RECTANGLE_ARB, buffer->buf_id );
246 glTexImage2D( GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL );
247 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_WRAP_S, GL_CLAMP );
248 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_WRAP_T, GL_CLAMP );
249 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
250 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
251 return buffer;
252 }
254 /**
255 * Ensure the texture in the given render buffer is not attached to a
256 * framebuffer (ie, so we can safely use it as a texture during the rendering
257 * cycle, or before deletion).
258 */
259 static void gl_fbo_detach_render_buffer( render_buffer_t buffer )
260 {
261 int i,j;
262 for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
263 if( fbo[i].width == buffer->width && fbo[i].height == buffer->height ) {
264 for( j=0; j<gl_fbo_max_attachments; j++ ) {
265 if( fbo[i].tex_ids[j] == buffer->buf_id ) {
266 glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo[i].fb_id);
267 glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, ATTACHMENT_POINT(j),
268 GL_TEXTURE_RECTANGLE_ARB, GL_NONE, 0 );
269 fbo[i].tex_ids[j] = -1;
270 return;
271 }
272 }
273 break;
274 }
275 }
276 }
278 static void gl_fbo_destroy_render_buffer( render_buffer_t buffer )
279 {
280 int i,j;
282 gl_fbo_detach_render_buffer( buffer );
284 if( buffer->buf_id != buffer->tex_id ) {
285 // If tex_id was set at buffer creation, we don't own the texture.
286 // Otherwise, delete it now.
287 GLuint tex = buffer->buf_id;
288 glDeleteTextures( 1, &tex );
289 }
290 buffer->buf_id = 0;
291 buffer->tex_id = 0;
292 free( buffer );
293 }
295 static gboolean gl_fbo_set_render_target( render_buffer_t buffer )
296 {
297 glFinish();
298 glGetError();
299 int fb = gl_fbo_get_framebuffer( buffer->width, buffer->height );
300 gl_fbo_attach_texture( fb, buffer->buf_id );
301 /* setup the gl context */
302 glViewport( 0, 0, buffer->width, buffer->height );
304 return TRUE;
305 }
307 static void gl_fbo_finish_render( render_buffer_t buffer )
308 {
309 glFinish();
310 glGetError();
311 gl_fbo_detach_render_buffer(buffer);
312 }
314 /**
315 * Render the texture holding the given buffer to the front window
316 * buffer.
317 */
318 static void gl_fbo_display_render_buffer( render_buffer_t buffer )
319 {
320 glFinish();
321 gl_fbo_detach();
322 gl_display_render_buffer( buffer );
323 }
325 static void gl_fbo_load_frame_buffer( frame_buffer_t frame, render_buffer_t buffer )
326 {
327 glFinish();
328 gl_fbo_detach();
329 gl_load_frame_buffer( frame, buffer->buf_id );
330 }
332 static void gl_fbo_display_blank( uint32_t colour )
333 {
334 glFinish();
335 gl_fbo_detach();
336 gl_display_blank( colour );
337 }
339 void gl_fbo_detach()
340 {
341 glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, 0 );
342 /* Make sure texture attachment is not a current draw/read buffer */
343 glDrawBuffer( GL_FRONT );
344 glReadBuffer( GL_FRONT );
345 }
347 static gboolean gl_fbo_read_render_buffer( unsigned char *target, render_buffer_t buffer,
348 int rowstride, int format )
349 {
350 glGetError();
351 int fb = gl_fbo_get_framebuffer( buffer->width, buffer->height );
352 gl_fbo_attach_texture( fb, buffer->buf_id );
353 return gl_read_render_buffer( target, buffer, rowstride, format );
354 }
356 #else
357 gboolean gl_fbo_is_supported()
358 {
359 return FALSE;
360 }
362 void gl_fbo_init( display_driver_t driver )
363 {
364 }
366 #endif
.