filename | src/drivers/gl_common.c |
changeset | 352:f0df7a6d4703 |
next | 424:421d68e78c46 |
author | nkeynes |
date | Sun Feb 11 10:09:32 2007 +0000 (17 years ago) |
permissions | -rw-r--r-- |
last change | Bug 27: Implement opengl framebuffer objects Rewrite much of the final video output stage. Now uses generic "render buffers", implemented on GL using framebuffer objects + textures. |
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nkeynes@352 | 1 | /** |
nkeynes@352 | 2 | * $Id: gl_common.c,v 1.1 2007-02-11 10:09:32 nkeynes Exp $ |
nkeynes@352 | 3 | * |
nkeynes@352 | 4 | * Common GL code that doesn't depend on a specific implementation |
nkeynes@352 | 5 | * |
nkeynes@352 | 6 | * Copyright (c) 2005 Nathan Keynes. |
nkeynes@352 | 7 | * |
nkeynes@352 | 8 | * This program is free software; you can redistribute it and/or modify |
nkeynes@352 | 9 | * it under the terms of the GNU General Public License as published by |
nkeynes@352 | 10 | * the Free Software Foundation; either version 2 of the License, or |
nkeynes@352 | 11 | * (at your option) any later version. |
nkeynes@352 | 12 | * |
nkeynes@352 | 13 | * This program is distributed in the hope that it will be useful, |
nkeynes@352 | 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
nkeynes@352 | 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
nkeynes@352 | 16 | * GNU General Public License for more details. |
nkeynes@352 | 17 | */ |
nkeynes@352 | 18 | |
nkeynes@352 | 19 | #include <GL/gl.h> |
nkeynes@352 | 20 | #include "dream.h" |
nkeynes@352 | 21 | #include "drivers/gl_common.h" |
nkeynes@352 | 22 | |
nkeynes@352 | 23 | extern uint32_t video_width, video_height; |
nkeynes@352 | 24 | |
nkeynes@352 | 25 | char *required_extensions[] = { "GL_EXT_framebuffer_object", NULL }; |
nkeynes@352 | 26 | |
nkeynes@352 | 27 | /** |
nkeynes@352 | 28 | * Test if a specific extension is supported. From opengl.org |
nkeynes@352 | 29 | * @param extension extension name to check for |
nkeynes@352 | 30 | * @return TRUE if supported, otherwise FALSE. |
nkeynes@352 | 31 | */ |
nkeynes@352 | 32 | gboolean isGLExtensionSupported( const char *extension ) |
nkeynes@352 | 33 | { |
nkeynes@352 | 34 | const GLubyte *extensions = NULL; |
nkeynes@352 | 35 | const GLubyte *start; |
nkeynes@352 | 36 | GLubyte *where, *terminator; |
nkeynes@352 | 37 | |
nkeynes@352 | 38 | /* Extension names should not have spaces. */ |
nkeynes@352 | 39 | where = (GLubyte *) strchr(extension, ' '); |
nkeynes@352 | 40 | if (where || *extension == '\0') |
nkeynes@352 | 41 | return 0; |
nkeynes@352 | 42 | extensions = glGetString(GL_EXTENSIONS); |
nkeynes@352 | 43 | /* It takes a bit of care to be fool-proof about parsing the |
nkeynes@352 | 44 | OpenGL extensions string. Don't be fooled by sub-strings, |
nkeynes@352 | 45 | etc. */ |
nkeynes@352 | 46 | start = extensions; |
nkeynes@352 | 47 | for (;;) { |
nkeynes@352 | 48 | where = (GLubyte *) strstr((const char *) start, extension); |
nkeynes@352 | 49 | if (!where) |
nkeynes@352 | 50 | break; |
nkeynes@352 | 51 | terminator = where + strlen(extension); |
nkeynes@352 | 52 | if (where == start || *(where - 1) == ' ') |
nkeynes@352 | 53 | if (*terminator == ' ' || *terminator == '\0') |
nkeynes@352 | 54 | return TRUE; |
nkeynes@352 | 55 | start = terminator; |
nkeynes@352 | 56 | } |
nkeynes@352 | 57 | return FALSE; |
nkeynes@352 | 58 | } |
nkeynes@352 | 59 | |
nkeynes@352 | 60 | gboolean hasRequiredGLExtensions( ) |
nkeynes@352 | 61 | { |
nkeynes@352 | 62 | int i; |
nkeynes@352 | 63 | gboolean isOK = TRUE; |
nkeynes@352 | 64 | |
nkeynes@352 | 65 | for( i=0; required_extensions[i] != NULL; i++ ) { |
nkeynes@352 | 66 | if( !isGLExtensionSupported(required_extensions[i]) ) { |
nkeynes@352 | 67 | ERROR( "Required OpenGL extension not supported: %s", required_extensions[i] ); |
nkeynes@352 | 68 | isOK = FALSE; |
nkeynes@352 | 69 | } |
nkeynes@352 | 70 | } |
nkeynes@352 | 71 | return isOK; |
nkeynes@352 | 72 | } |
nkeynes@352 | 73 | |
nkeynes@352 | 74 | |
nkeynes@352 | 75 | gboolean gl_display_frame_buffer( frame_buffer_t frame ) |
nkeynes@352 | 76 | { |
nkeynes@352 | 77 | GLenum type = colour_formats[frame->colour_format].type; |
nkeynes@352 | 78 | GLenum format = colour_formats[frame->colour_format].format; |
nkeynes@352 | 79 | int bpp = colour_formats[frame->colour_format].bpp; |
nkeynes@352 | 80 | GLint texid; |
nkeynes@352 | 81 | |
nkeynes@352 | 82 | glViewport( 0, 0, video_width, video_height ); |
nkeynes@352 | 83 | glMatrixMode(GL_PROJECTION); |
nkeynes@352 | 84 | glLoadIdentity(); |
nkeynes@352 | 85 | glOrtho( 0, video_width, video_height, 0, 0, -65535 ); |
nkeynes@352 | 86 | glMatrixMode(GL_MODELVIEW); |
nkeynes@352 | 87 | glLoadIdentity(); |
nkeynes@352 | 88 | |
nkeynes@352 | 89 | /* Disable everything */ |
nkeynes@352 | 90 | glDisable( GL_TEXTURE_2D ); |
nkeynes@352 | 91 | glDisable( GL_ALPHA_TEST ); |
nkeynes@352 | 92 | glDisable( GL_DEPTH_TEST ); |
nkeynes@352 | 93 | glDisable( GL_SCISSOR_TEST ); |
nkeynes@352 | 94 | glDisable( GL_CULL_FACE ); |
nkeynes@352 | 95 | |
nkeynes@352 | 96 | float scale = ((float)video_height) / frame->height; |
nkeynes@352 | 97 | int rowstride = (frame->rowstride / bpp) - frame->width; |
nkeynes@352 | 98 | |
nkeynes@352 | 99 | |
nkeynes@352 | 100 | /* |
nkeynes@352 | 101 | glGenTextures( 1, &texid ); |
nkeynes@352 | 102 | glBindTexture( GL_TEXTURE_2D, texid ); |
nkeynes@352 | 103 | glTexImage2D( GL_TEXTURE_2D, 0, colour_formats[frame->colour_format].int_format, |
nkeynes@352 | 104 | frame->width, frame->height, 0, format, type, frame->data ); |
nkeynes@352 | 105 | glBegin( GL_QUADS ); |
nkeynes@352 | 106 | glTexCoord2i( 0, 1.0 ); |
nkeynes@352 | 107 | glVertex2f( 0.0, 0.0 ); |
nkeynes@352 | 108 | glTexCoord2i( 1.0, 1.0 ); |
nkeynes@352 | 109 | glVertex2f( frame->width, 0.0 ); |
nkeynes@352 | 110 | glTexCoord2i( 1.0, 0.0 ); |
nkeynes@352 | 111 | glVertex2f( frame->width, frame->height ); |
nkeynes@352 | 112 | glTexCoord2i( 0, 0.0 ); |
nkeynes@352 | 113 | glVertex2f( 0.0, frame->height ); |
nkeynes@352 | 114 | glEnd(); |
nkeynes@352 | 115 | glDeleteTextures( 1, &texid ); |
nkeynes@352 | 116 | */ |
nkeynes@352 | 117 | glRasterPos2i( 0, 0 ); |
nkeynes@352 | 118 | glPixelZoom( 1.0f, -scale ); |
nkeynes@352 | 119 | glPixelStorei( GL_UNPACK_ROW_LENGTH, rowstride ); |
nkeynes@352 | 120 | glDrawPixels( frame->width, frame->height, format, type, |
nkeynes@352 | 121 | frame->data ); |
nkeynes@352 | 122 | |
nkeynes@352 | 123 | glFlush(); |
nkeynes@352 | 124 | return TRUE; |
nkeynes@352 | 125 | } |
nkeynes@352 | 126 | |
nkeynes@352 | 127 | gboolean gl_display_blank( uint32_t colour ) |
nkeynes@352 | 128 | { |
nkeynes@352 | 129 | glViewport( 0, 0, video_width, video_height ); |
nkeynes@352 | 130 | glMatrixMode( GL_PROJECTION ); |
nkeynes@352 | 131 | glLoadIdentity(); |
nkeynes@352 | 132 | glOrtho( 0, video_width, video_height, 0, 0, -65535 ); |
nkeynes@352 | 133 | glMatrixMode(GL_MODELVIEW); |
nkeynes@352 | 134 | glLoadIdentity(); |
nkeynes@352 | 135 | glColor3b( (colour >> 16) & 0xFF, (colour >> 8) & 0xFF, colour & 0xFF ); |
nkeynes@352 | 136 | glRecti(0,0, video_width, video_height ); |
nkeynes@352 | 137 | glFlush(); |
nkeynes@352 | 138 | return TRUE; |
nkeynes@352 | 139 | } |
nkeynes@352 | 140 | |
nkeynes@352 | 141 | /** |
nkeynes@352 | 142 | * Generic GL read_render_buffer. This function assumes that the caller |
nkeynes@352 | 143 | * has already set the appropriate glReadBuffer(); in other words, unless |
nkeynes@352 | 144 | * there's only one buffer this needs to be wrapped. |
nkeynes@352 | 145 | */ |
nkeynes@352 | 146 | gboolean gl_read_render_buffer( render_buffer_t buffer, char *target ) |
nkeynes@352 | 147 | { |
nkeynes@352 | 148 | if( buffer->address == -1 ) |
nkeynes@352 | 149 | return FALSE; |
nkeynes@352 | 150 | glFinish(); |
nkeynes@352 | 151 | GLenum type = colour_formats[buffer->colour_format].type; |
nkeynes@352 | 152 | GLenum format = colour_formats[buffer->colour_format].format; |
nkeynes@352 | 153 | int line_size = buffer->width * colour_formats[buffer->colour_format].bpp; |
nkeynes@352 | 154 | int size = line_size * buffer->height; |
nkeynes@352 | 155 | int rowstride = (buffer->rowstride / colour_formats[buffer->colour_format].bpp) - buffer->width; |
nkeynes@352 | 156 | // glPixelStorei( GL_PACK_ROW_LENGTH, rowstride ); |
nkeynes@352 | 157 | |
nkeynes@352 | 158 | glReadPixels( 0, 0, buffer->width, buffer->height, format, type, target ); |
nkeynes@352 | 159 | return TRUE; |
nkeynes@352 | 160 | } |
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