filename | src/drivers/gl_fbo.c |
changeset | 540:a3767018a96d |
prev | 477:9a373f2ff009 |
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author | nkeynes |
date | Thu Nov 22 11:10:15 2007 +0000 (16 years ago) |
permissions | -rw-r--r-- |
last change | Re-add "Load Binary" menu item (misplaced in GUI rewrite) Prevent running with no code loaded |
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1 /**
2 * $Id: gl_fbo.c,v 1.7 2007-10-31 09:10:23 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 <stdlib.h>
28 #include "lxdream.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 void gl_fbo_load_frame_buffer( frame_buffer_t frame, render_buffer_t buffer );
41 static gboolean gl_fbo_display_blank( uint32_t colour );
42 static gboolean gl_fbo_read_render_buffer( unsigned char *target, render_buffer_t buffer, int rowstride, int format );
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->load_frame_buffer = gl_fbo_load_frame_buffer;
97 driver->display_blank = gl_fbo_display_blank;
98 driver->read_render_buffer = gl_fbo_read_render_buffer;
100 glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
101 glDrawBuffer(GL_FRONT);
102 glReadBuffer(GL_FRONT);
103 }
105 void gl_fbo_shutdown()
106 {
107 int i;
108 glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, 0 );
109 for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
110 glDeleteFramebuffersEXT( 1, &fbo[i].fb_id );
111 glDeleteRenderbuffersEXT( 2, &fbo[i].depth_id );
112 }
113 }
115 void gl_fbo_setup_framebuffer( int bufno, int width, int height )
116 {
117 glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo[bufno].fb_id);
118 glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
119 glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT24, width, height);
120 glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
121 GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
122 /* Stencil doesn't work on ATI, and we're not using it at the moment anyway, so...
123 glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fbo[bufno].stencil_id);
124 glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_STENCIL_INDEX, width, height);
125 glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_STENCIL_ATTACHMENT_EXT,
126 GL_RENDERBUFFER_EXT, fbo[bufno].stencil_id);
127 */
128 fbo[bufno].width = width;
129 fbo[bufno].height = height;
130 }
132 int gl_fbo_get_framebuffer( int width, int height )
133 {
134 int bufno = -1, i;
135 /* find a compatible framebuffer context */
136 for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
137 if( fbo[i].width == -1 && bufno == -1 ) {
138 bufno = i;
139 } else if( fbo[i].width == width && fbo[i].height == height ) {
140 bufno = i;
141 break;
142 }
143 }
144 if( bufno == -1 ) {
145 bufno = last_used_fbo + 1;
146 if( bufno > MAX_FRAMEBUFFERS ) {
147 bufno = 0;
148 }
149 last_used_fbo = bufno;
150 }
151 if( fbo[bufno].width == width && fbo[bufno].height == height ) {
152 glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, fbo[bufno].fb_id );
153 } else {
154 gl_fbo_setup_framebuffer( bufno, width, height );
155 }
156 return bufno;
157 }
159 /**
160 * Attach a texture to the framebuffer. The texture must already be initialized
161 * to the correct dimensions etc.
162 */
163 static GLint gl_fbo_attach_texture( int fbo_no, GLint tex_id ) {
164 int attach = -1, i;
165 for( i=0; i<MAX_TEXTURES_PER_FB; i++ ) {
166 if( fbo[fbo_no].tex_ids[i] == tex_id ) {
167 glDrawBuffer(ATTACHMENT_POINTS[i]);
168 glReadBuffer(ATTACHMENT_POINTS[i]);
169 return ATTACHMENT_POINTS[i]; // already attached
170 } else if( fbo[fbo_no].tex_ids[i] == -1 && attach == -1 ) {
171 attach = i;
172 }
173 }
174 if( attach == -1 ) {
175 /* should never happen */
176 attach = 0;
177 }
178 fbo[fbo_no].tex_ids[attach] = tex_id;
179 glBindTexture( GL_TEXTURE_RECTANGLE_ARB, 0 ); // Ensure the output texture is unbound
180 glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, ATTACHMENT_POINTS[attach],
181 GL_TEXTURE_RECTANGLE_ARB, tex_id, 0 );
182 /* Set draw/read buffers by default */
183 glDrawBuffer(ATTACHMENT_POINTS[attach]);
184 glReadBuffer(ATTACHMENT_POINTS[attach]);
187 GLint status = glGetError();
188 if( status != GL_NO_ERROR ) {
189 ERROR( "GL error setting render target (%x)!", status );
190 }
191 status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
192 if( status != GL_FRAMEBUFFER_COMPLETE_EXT ) {
193 ERROR( "Framebuffer failure: %x", status );
194 exit(1);
195 }
197 return ATTACHMENT_POINTS[attach];
198 }
200 static render_buffer_t gl_fbo_create_render_buffer( uint32_t width, uint32_t height )
201 {
202 render_buffer_t buffer = calloc( sizeof(struct render_buffer), 1 );
203 buffer->width = width;
204 buffer->height = height;
205 glGenTextures( 1, &buffer->buf_id );
206 glBindTexture( GL_TEXTURE_RECTANGLE_ARB, buffer->buf_id );
207 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_WRAP_S, GL_CLAMP );
208 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_WRAP_T, GL_CLAMP );
209 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
210 glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
211 glTexImage2D( GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL );
212 return buffer;
213 }
215 static void gl_fbo_destroy_render_buffer( render_buffer_t buffer )
216 {
217 int i,j;
218 for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
219 for( j=0; j < MAX_TEXTURES_PER_FB; j++ ) {
220 if( fbo[i].tex_ids[j] == buffer->buf_id ) {
221 glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo[i].fb_id);
222 glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, ATTACHMENT_POINTS[j],
223 GL_TEXTURE_RECTANGLE_ARB, GL_NONE, 0 );
224 fbo[i].tex_ids[j] = -1;
225 }
226 }
227 }
229 glDeleteTextures( 1, &buffer->buf_id );
230 buffer->buf_id = 0;
231 free( buffer );
232 }
234 static gboolean gl_fbo_set_render_target( render_buffer_t buffer )
235 {
236 glFinish();
237 glGetError();
238 int fb = gl_fbo_get_framebuffer( buffer->width, buffer->height );
239 gl_fbo_attach_texture( fb, buffer->buf_id );
240 /* setup the gl context */
241 glViewport( 0, 0, buffer->width, buffer->height );
243 return TRUE;
244 }
246 /**
247 * Render the texture holding the given buffer to the front window
248 * buffer.
249 */
250 static gboolean gl_fbo_display_render_buffer( render_buffer_t buffer )
251 {
252 glFinish();
253 gl_fbo_detach();
254 gl_display_render_buffer( buffer );
255 return TRUE;
256 }
258 static void gl_fbo_load_frame_buffer( frame_buffer_t frame, render_buffer_t buffer )
259 {
260 glFinish();
261 gl_fbo_detach();
262 gl_load_frame_buffer( frame, buffer );
263 }
265 static gboolean gl_fbo_display_blank( uint32_t colour )
266 {
267 glFinish();
268 gl_fbo_detach();
269 return gl_display_blank( colour );
270 }
272 void gl_fbo_detach()
273 {
274 glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, 0 );
275 glDrawBuffer( GL_FRONT );
276 glReadBuffer( GL_FRONT );
277 }
279 static gboolean gl_fbo_read_render_buffer( unsigned char *target, render_buffer_t buffer,
280 int rowstride, int format )
281 {
282 int fb = gl_fbo_get_framebuffer( buffer->width, buffer->height );
283 gl_fbo_attach_texture( fb, buffer->buf_id );
284 return gl_read_render_buffer( target, buffer, rowstride, format );
285 }
.