nkeynes@352 | 1 | /**
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nkeynes@424 | 2 | * $Id: gl_fbo.c,v 1.2 2007-10-07 05:42:25 nkeynes Exp $
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nkeynes@352 | 3 | *
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nkeynes@352 | 4 | * GL framebuffer-based driver shell. This requires the EXT_framebuffer_object
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nkeynes@352 | 5 | * extension, but is much nicer/faster/etc than pbuffers when it's available.
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nkeynes@352 | 6 | * This is (optionally) used indirectly by the top-level GLX driver.
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nkeynes@352 | 7 | *
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nkeynes@352 | 8 | * Strategy-wise, we maintain 2 framebuffers with up to 4 target colour
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nkeynes@352 | 9 | * buffers a piece. Effectively this reserves one fb for display output,
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nkeynes@352 | 10 | * and the other for texture output (each fb has a single size).
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nkeynes@352 | 11 | *
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nkeynes@352 | 12 | * Copyright (c) 2005 Nathan Keynes.
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nkeynes@352 | 13 | *
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nkeynes@352 | 14 | * This program is free software; you can redistribute it and/or modify
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nkeynes@352 | 15 | * it under the terms of the GNU General Public License as published by
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nkeynes@352 | 16 | * the Free Software Foundation; either version 2 of the License, or
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nkeynes@352 | 17 | * (at your option) any later version.
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nkeynes@352 | 18 | *
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nkeynes@352 | 19 | * This program is distributed in the hope that it will be useful,
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nkeynes@352 | 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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nkeynes@352 | 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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nkeynes@352 | 22 | * GNU General Public License for more details.
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nkeynes@352 | 23 | */
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nkeynes@352 | 24 |
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nkeynes@424 | 25 | #define GL_GLEXT_PROTOTYPES 1
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nkeynes@424 | 26 |
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nkeynes@352 | 27 | #include <GL/gl.h>
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nkeynes@424 | 28 | #include <GL/glext.h>
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nkeynes@352 | 29 | #include "display.h"
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nkeynes@424 | 30 | #include "drivers/video_x11.h"
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nkeynes@424 | 31 | #include "drivers/gl_common.h"
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nkeynes@352 | 32 |
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nkeynes@352 | 33 | #define MAX_FRAMEBUFFERS 2
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nkeynes@352 | 34 | #define MAX_TEXTURES_PER_FB 4
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nkeynes@352 | 35 |
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nkeynes@352 | 36 | static render_buffer_t gl_fbo_create_render_buffer( uint32_t width, uint32_t height );
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nkeynes@352 | 37 | static void gl_fbo_destroy_render_buffer( render_buffer_t buffer );
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nkeynes@352 | 38 | static gboolean gl_fbo_set_render_target( render_buffer_t buffer );
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nkeynes@352 | 39 | static gboolean gl_fbo_display_render_buffer( render_buffer_t buffer );
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nkeynes@352 | 40 | static gboolean gl_fbo_display_frame_buffer( frame_buffer_t buffer );
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nkeynes@352 | 41 | static gboolean gl_fbo_display_blank( uint32_t colour );
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nkeynes@352 | 42 | static gboolean gl_fbo_read_render_buffer( render_buffer_t buffer, char *target );
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nkeynes@352 | 43 |
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nkeynes@352 | 44 | extern uint32_t video_width, video_height;
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nkeynes@352 | 45 |
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nkeynes@352 | 46 | /**
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nkeynes@352 | 47 | * Framebuffer info structure
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nkeynes@352 | 48 | */
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nkeynes@352 | 49 | struct gl_fbo_info {
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nkeynes@352 | 50 | GLuint fb_id;
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nkeynes@352 | 51 | GLuint depth_id;
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nkeynes@352 | 52 | GLuint stencil_id;
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nkeynes@352 | 53 | GLuint tex_ids[MAX_TEXTURES_PER_FB];
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nkeynes@352 | 54 | int width, height;
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nkeynes@352 | 55 | };
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nkeynes@352 | 56 |
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nkeynes@352 | 57 | static struct gl_fbo_info fbo[MAX_FRAMEBUFFERS];
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nkeynes@352 | 58 | const static int ATTACHMENT_POINTS[MAX_TEXTURES_PER_FB] = {
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nkeynes@352 | 59 | GL_COLOR_ATTACHMENT0_EXT, GL_COLOR_ATTACHMENT1_EXT,
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nkeynes@352 | 60 | GL_COLOR_ATTACHMENT2_EXT, GL_COLOR_ATTACHMENT3_EXT };
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nkeynes@352 | 61 | static int last_used_fbo;
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nkeynes@352 | 62 |
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nkeynes@352 | 63 | gboolean gl_fbo_is_supported()
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nkeynes@352 | 64 | {
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nkeynes@352 | 65 | return isGLExtensionSupported("GL_EXT_framebuffer_object");
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nkeynes@352 | 66 | }
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nkeynes@352 | 67 |
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nkeynes@352 | 68 | /**
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nkeynes@352 | 69 | * Construct the initial frame buffers and allocate ids for everything.
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nkeynes@352 | 70 | * The render handling driver methods are set to the fbo versions.
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nkeynes@352 | 71 | */
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nkeynes@352 | 72 | void gl_fbo_init( display_driver_t driver )
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nkeynes@352 | 73 | {
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nkeynes@352 | 74 | int i,j;
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nkeynes@424 | 75 | GLuint fbids[MAX_FRAMEBUFFERS];
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nkeynes@424 | 76 | GLuint rbids[MAX_FRAMEBUFFERS*2]; /* depth buffer, stencil buffer per fb */
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nkeynes@352 | 77 |
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nkeynes@424 | 78 | glGenFramebuffersEXT( MAX_FRAMEBUFFERS, &fbids[0] );
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nkeynes@424 | 79 | glGenRenderbuffersEXT( MAX_FRAMEBUFFERS*2, &rbids[0] );
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nkeynes@352 | 80 | for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
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nkeynes@352 | 81 | fbo[i].fb_id = fbids[i];
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nkeynes@352 | 82 | fbo[i].depth_id = rbids[i*2];
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nkeynes@352 | 83 | fbo[i].stencil_id = rbids[i*2+1];
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nkeynes@352 | 84 | fbo[i].width = -1;
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nkeynes@352 | 85 | fbo[i].height = -1;
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nkeynes@352 | 86 | for( j=0; j<MAX_TEXTURES_PER_FB; j++ ) {
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nkeynes@352 | 87 | fbo[i].tex_ids[j] = -1;
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nkeynes@352 | 88 | }
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nkeynes@352 | 89 | }
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nkeynes@352 | 90 | last_used_fbo = 0;
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nkeynes@352 | 91 |
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nkeynes@352 | 92 | driver->create_render_buffer = gl_fbo_create_render_buffer;
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nkeynes@352 | 93 | driver->destroy_render_buffer = gl_fbo_destroy_render_buffer;
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nkeynes@352 | 94 | driver->set_render_target = gl_fbo_set_render_target;
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nkeynes@352 | 95 | driver->display_render_buffer = gl_fbo_display_render_buffer;
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nkeynes@352 | 96 | driver->display_frame_buffer = gl_fbo_display_frame_buffer;
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nkeynes@352 | 97 | driver->display_blank = gl_fbo_display_blank;
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nkeynes@352 | 98 | driver->read_render_buffer = gl_fbo_read_render_buffer;
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nkeynes@352 | 99 | }
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nkeynes@352 | 100 |
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nkeynes@352 | 101 | void gl_fbo_shutdown()
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nkeynes@352 | 102 | {
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nkeynes@352 | 103 | int i;
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nkeynes@352 | 104 | glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, 0 );
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nkeynes@352 | 105 | for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
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nkeynes@352 | 106 | glDeleteFramebuffersEXT( 1, &fbo[i].fb_id );
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nkeynes@352 | 107 | glDeleteRenderbuffersEXT( 2, &fbo[i].depth_id );
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nkeynes@352 | 108 | }
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nkeynes@352 | 109 | }
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nkeynes@352 | 110 |
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nkeynes@352 | 111 | void gl_fbo_setup_framebuffer( int bufno, int width, int height )
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nkeynes@352 | 112 | {
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nkeynes@352 | 113 | glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo[bufno].fb_id);
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nkeynes@352 | 114 | glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
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nkeynes@352 | 115 | glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT24, width, height);
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nkeynes@352 | 116 | glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
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nkeynes@352 | 117 | GL_RENDERBUFFER_EXT, fbo[bufno].depth_id);
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nkeynes@352 | 118 | /* Stencil doesn't work on ATI, and we're not using it at the moment anyway, so...
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nkeynes@352 | 119 | glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fbo[bufno].stencil_id);
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nkeynes@352 | 120 | glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_STENCIL_INDEX, width, height);
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nkeynes@352 | 121 | glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_STENCIL_ATTACHMENT_EXT,
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nkeynes@352 | 122 | GL_RENDERBUFFER_EXT, fbo[bufno].stencil_id);
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nkeynes@352 | 123 | */
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nkeynes@352 | 124 | fbo[bufno].width = width;
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nkeynes@352 | 125 | fbo[bufno].height = height;
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nkeynes@352 | 126 | }
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nkeynes@352 | 127 |
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nkeynes@352 | 128 | int gl_fbo_get_framebuffer( int width, int height )
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nkeynes@352 | 129 | {
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nkeynes@352 | 130 | int bufno = -1, i;
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nkeynes@352 | 131 | /* find a compatible framebuffer context */
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nkeynes@352 | 132 | for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
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nkeynes@352 | 133 | if( fbo[i].width == -1 && bufno == -1 ) {
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nkeynes@352 | 134 | bufno = i;
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nkeynes@352 | 135 | } else if( fbo[i].width == width && fbo[i].height == height ) {
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nkeynes@352 | 136 | bufno = i;
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nkeynes@352 | 137 | break;
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nkeynes@352 | 138 | }
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nkeynes@352 | 139 | }
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nkeynes@352 | 140 | if( bufno == -1 ) {
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nkeynes@352 | 141 | bufno = last_used_fbo + 1;
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nkeynes@352 | 142 | if( bufno > MAX_FRAMEBUFFERS ) {
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nkeynes@352 | 143 | bufno = 0;
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nkeynes@352 | 144 | }
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nkeynes@352 | 145 | last_used_fbo = bufno;
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nkeynes@352 | 146 | }
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nkeynes@352 | 147 | if( fbo[bufno].width == width && fbo[bufno].height == height ) {
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nkeynes@352 | 148 | glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, fbo[bufno].fb_id );
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nkeynes@352 | 149 | } else {
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nkeynes@352 | 150 | gl_fbo_setup_framebuffer( bufno, width, height );
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nkeynes@352 | 151 | }
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nkeynes@352 | 152 | return bufno;
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nkeynes@352 | 153 | }
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nkeynes@352 | 154 |
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nkeynes@352 | 155 | /**
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nkeynes@352 | 156 | * Attach a texture to the framebuffer. The texture must already be initialized
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nkeynes@352 | 157 | * to the correct dimensions etc.
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nkeynes@352 | 158 | */
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nkeynes@352 | 159 | static GLint gl_fbo_attach_texture( int fbo_no, GLint tex_id ) {
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nkeynes@352 | 160 | int attach = -1, i;
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nkeynes@352 | 161 | for( i=0; i<MAX_TEXTURES_PER_FB; i++ ) {
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nkeynes@352 | 162 | if( fbo[fbo_no].tex_ids[i] == tex_id ) {
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nkeynes@352 | 163 | glDrawBuffer(ATTACHMENT_POINTS[i]);
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nkeynes@352 | 164 | glReadBuffer(ATTACHMENT_POINTS[i]);
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nkeynes@352 | 165 | return ATTACHMENT_POINTS[i]; // already attached
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nkeynes@352 | 166 | } else if( fbo[fbo_no].tex_ids[i] == -1 && attach == -1 ) {
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nkeynes@352 | 167 | attach = i;
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nkeynes@352 | 168 | }
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nkeynes@352 | 169 | }
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nkeynes@352 | 170 | if( attach == -1 ) {
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nkeynes@352 | 171 | /* should never happen */
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nkeynes@352 | 172 | attach = 0;
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nkeynes@352 | 173 | }
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nkeynes@352 | 174 | fbo[fbo_no].tex_ids[attach] = tex_id;
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nkeynes@352 | 175 | glBindTexture( GL_TEXTURE_RECTANGLE_ARB, 0 ); // Ensure the output texture is unbound
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nkeynes@352 | 176 | glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, ATTACHMENT_POINTS[attach],
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nkeynes@352 | 177 | GL_TEXTURE_RECTANGLE_ARB, tex_id, 0 );
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nkeynes@352 | 178 | /* Set draw/read buffers by default */
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nkeynes@352 | 179 | glDrawBuffer(ATTACHMENT_POINTS[attach]);
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nkeynes@352 | 180 | glReadBuffer(ATTACHMENT_POINTS[attach]);
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nkeynes@352 | 181 |
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nkeynes@352 | 182 |
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nkeynes@352 | 183 | GLint status = glGetError();
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nkeynes@352 | 184 | if( status != GL_NO_ERROR ) {
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nkeynes@352 | 185 | ERROR( "GL error setting render target (%x)!", status );
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nkeynes@352 | 186 | }
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nkeynes@352 | 187 | status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
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nkeynes@352 | 188 | if( status != GL_FRAMEBUFFER_COMPLETE_EXT ) {
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nkeynes@352 | 189 | ERROR( "Framebuffer failure: %x", status );
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nkeynes@352 | 190 | exit(1);
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nkeynes@352 | 191 | }
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nkeynes@352 | 192 |
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nkeynes@352 | 193 | return ATTACHMENT_POINTS[attach];
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nkeynes@352 | 194 | }
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nkeynes@352 | 195 |
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nkeynes@352 | 196 | static render_buffer_t gl_fbo_create_render_buffer( uint32_t width, uint32_t height )
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nkeynes@352 | 197 | {
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nkeynes@352 | 198 | render_buffer_t buffer = calloc( sizeof(struct render_buffer), 1 );
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nkeynes@352 | 199 | buffer->width = width;
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nkeynes@352 | 200 | buffer->height = height;
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nkeynes@352 | 201 | glGenTextures( 1, &buffer->buf_id );
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nkeynes@352 | 202 | glBindTexture( GL_TEXTURE_RECTANGLE_ARB, buffer->buf_id );
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nkeynes@352 | 203 | glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_WRAP_S, GL_CLAMP );
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nkeynes@352 | 204 | glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_WRAP_T, GL_CLAMP );
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nkeynes@352 | 205 | glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
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nkeynes@352 | 206 | glTexParameteri( GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
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nkeynes@352 | 207 | glTexImage2D( GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL );
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nkeynes@352 | 208 | return buffer;
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nkeynes@352 | 209 | }
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nkeynes@352 | 210 |
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nkeynes@352 | 211 | static void gl_fbo_destroy_render_buffer( render_buffer_t buffer )
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nkeynes@352 | 212 | {
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nkeynes@352 | 213 | int i,j;
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nkeynes@352 | 214 | for( i=0; i<MAX_FRAMEBUFFERS; i++ ) {
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nkeynes@352 | 215 | for( j=0; j < MAX_TEXTURES_PER_FB; j++ ) {
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nkeynes@352 | 216 | if( fbo[i].tex_ids[j] == buffer->buf_id ) {
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nkeynes@352 | 217 | glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, ATTACHMENT_POINTS[j],
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nkeynes@352 | 218 | GL_TEXTURE_RECTANGLE_ARB, GL_NONE, 0 );
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nkeynes@352 | 219 | fbo[i].tex_ids[j] = -1;
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nkeynes@352 | 220 | }
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nkeynes@352 | 221 | }
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nkeynes@352 | 222 | }
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nkeynes@352 | 223 |
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nkeynes@352 | 224 | glDeleteTextures( 1, &buffer->buf_id );
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nkeynes@352 | 225 | buffer->buf_id = 0;
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nkeynes@352 | 226 | free( buffer );
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nkeynes@352 | 227 | }
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nkeynes@352 | 228 |
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nkeynes@352 | 229 | static gboolean gl_fbo_set_render_target( render_buffer_t buffer )
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nkeynes@352 | 230 | {
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nkeynes@352 | 231 | glGetError();
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nkeynes@352 | 232 | int fb = gl_fbo_get_framebuffer( buffer->width, buffer->height );
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nkeynes@424 | 233 | gl_fbo_attach_texture( fb, buffer->buf_id );
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nkeynes@352 | 234 | /* setup the gl context */
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nkeynes@352 | 235 | glViewport( 0, 0, buffer->width, buffer->height );
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nkeynes@352 | 236 |
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nkeynes@352 | 237 | return TRUE;
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nkeynes@352 | 238 | }
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nkeynes@352 | 239 |
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nkeynes@352 | 240 | /**
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nkeynes@352 | 241 | * Render the texture holding the given buffer to the front window
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nkeynes@352 | 242 | * buffer.
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nkeynes@352 | 243 | */
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nkeynes@352 | 244 | static gboolean gl_fbo_display_render_buffer( render_buffer_t buffer )
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nkeynes@352 | 245 | {
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nkeynes@352 | 246 | glFinish();
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nkeynes@352 | 247 | glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, 0 ); // real window
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nkeynes@352 | 248 | glViewport( 0, 0, video_width, video_height );
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nkeynes@352 | 249 | glEnable( GL_TEXTURE_RECTANGLE_ARB );
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nkeynes@352 | 250 | glBindTexture( GL_TEXTURE_RECTANGLE_ARB, buffer->buf_id );
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nkeynes@352 | 251 | glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE );
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nkeynes@352 | 252 | glDrawBuffer( GL_FRONT );
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nkeynes@352 | 253 | glReadBuffer( GL_FRONT );
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nkeynes@352 | 254 | glDisable( GL_ALPHA_TEST );
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nkeynes@352 | 255 | glDisable( GL_DEPTH_TEST );
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nkeynes@352 | 256 | glDisable( GL_SCISSOR_TEST );
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nkeynes@352 | 257 | glDisable( GL_CULL_FACE );
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nkeynes@352 | 258 |
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nkeynes@352 | 259 | glMatrixMode(GL_PROJECTION);
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nkeynes@352 | 260 | glLoadIdentity();
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nkeynes@352 | 261 | glOrtho( 0, buffer->width, buffer->height, 0, 0, -65535 );
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nkeynes@352 | 262 | glMatrixMode(GL_MODELVIEW);
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nkeynes@352 | 263 | glLoadIdentity();
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nkeynes@352 | 264 | glEnable( GL_BLEND );
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nkeynes@352 | 265 | glBlendFunc( GL_ONE, GL_ZERO );
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nkeynes@352 | 266 | glDisable( GL_DEPTH_TEST );
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nkeynes@352 | 267 | glBegin( GL_QUADS );
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nkeynes@352 | 268 | glTexCoord2i( 0, buffer->height );
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nkeynes@352 | 269 | glVertex2f( 0.0, 0.0 );
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nkeynes@352 | 270 | glTexCoord2i( buffer->width, buffer->height );
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nkeynes@352 | 271 | glVertex2f( buffer->width, 0.0 );
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nkeynes@352 | 272 | glTexCoord2i( buffer->width, 0 );
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nkeynes@352 | 273 | glVertex2f( buffer->width, buffer->height );
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nkeynes@352 | 274 | glTexCoord2i( 0, 0 );
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nkeynes@352 | 275 | glVertex2f( 0.0, buffer->height );
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nkeynes@352 | 276 | glEnd();
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nkeynes@352 | 277 | glDisable( GL_TEXTURE_RECTANGLE_ARB );
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nkeynes@352 | 278 | glFlush();
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nkeynes@352 | 279 | return TRUE;
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nkeynes@352 | 280 | }
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nkeynes@352 | 281 |
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nkeynes@352 | 282 | static gboolean gl_fbo_display_frame_buffer( frame_buffer_t buffer )
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nkeynes@352 | 283 | {
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nkeynes@352 | 284 | glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, 0 );
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nkeynes@352 | 285 | glDrawBuffer( GL_FRONT );
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nkeynes@352 | 286 | glReadBuffer( GL_FRONT );
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nkeynes@352 | 287 | return gl_display_frame_buffer( buffer );
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nkeynes@352 | 288 | }
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nkeynes@352 | 289 |
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nkeynes@352 | 290 | static gboolean gl_fbo_display_blank( uint32_t colour )
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nkeynes@352 | 291 | {
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nkeynes@352 | 292 | glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, 0 );
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nkeynes@352 | 293 | glDrawBuffer( GL_FRONT );
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nkeynes@352 | 294 | glReadBuffer( GL_FRONT );
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nkeynes@352 | 295 | return gl_display_blank( colour );
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nkeynes@352 | 296 | }
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nkeynes@352 | 297 |
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nkeynes@352 | 298 | static gboolean gl_fbo_read_render_buffer( render_buffer_t buffer, char *target )
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nkeynes@352 | 299 | {
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nkeynes@352 | 300 | int fb = gl_fbo_get_framebuffer( buffer->width, buffer->height );
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nkeynes@424 | 301 | gl_fbo_attach_texture( fb, buffer->buf_id );
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nkeynes@352 | 302 | return gl_read_render_buffer( buffer, target );
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nkeynes@352 | 303 | }
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nkeynes@352 | 304 |
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