1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/drivers/gl_common.c	Sun Feb 11 10:09:32 2007 +0000
     1.3 @@ -0,0 +1,160 @@
     1.4 +/**
     1.5 + * $Id: gl_common.c,v 1.1 2007-02-11 10:09:32 nkeynes Exp $
     1.6 + *
     1.7 + * Common GL code that doesn't depend on a specific implementation
     1.8 + *
     1.9 + * Copyright (c) 2005 Nathan Keynes.
    1.10 + *
    1.11 + * This program is free software; you can redistribute it and/or modify
    1.12 + * it under the terms of the GNU General Public License as published by
    1.13 + * the Free Software Foundation; either version 2 of the License, or
    1.14 + * (at your option) any later version.
    1.15 + *
    1.16 + * This program is distributed in the hope that it will be useful,
    1.17 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
    1.18 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    1.19 + * GNU General Public License for more details.
    1.20 + */
    1.21 +
    1.22 +#include <GL/gl.h>
    1.23 +#include "dream.h"
    1.24 +#include "drivers/gl_common.h"
    1.25 +
    1.26 +extern uint32_t video_width, video_height;
    1.27 +
    1.28 +char *required_extensions[] = { "GL_EXT_framebuffer_object", NULL };
    1.29 +
    1.30 +/**
    1.31 + * Test if a specific extension is supported. From opengl.org
    1.32 + * @param extension extension name to check for
    1.33 + * @return TRUE if supported, otherwise FALSE.
    1.34 + */
    1.35 +gboolean isGLExtensionSupported( const char *extension )
    1.36 +{
    1.37 +    const GLubyte *extensions = NULL;
    1.38 +    const GLubyte *start;
    1.39 +    GLubyte *where, *terminator;
    1.40 +
    1.41 +    /* Extension names should not have spaces. */
    1.42 +    where = (GLubyte *) strchr(extension, ' ');
    1.43 +    if (where || *extension == '\0')
    1.44 +	return 0;
    1.45 +    extensions = glGetString(GL_EXTENSIONS);
    1.46 +    /* It takes a bit of care to be fool-proof about parsing the
    1.47 +       OpenGL extensions string. Don't be fooled by sub-strings,
    1.48 +       etc. */
    1.49 +    start = extensions;
    1.50 +    for (;;) {
    1.51 +	where = (GLubyte *) strstr((const char *) start, extension);
    1.52 +	if (!where)
    1.53 +	    break;
    1.54 +	terminator = where + strlen(extension);
    1.55 +	if (where == start || *(where - 1) == ' ')
    1.56 +	    if (*terminator == ' ' || *terminator == '\0')
    1.57 +		return TRUE;
    1.58 +	start = terminator;
    1.59 +    }
    1.60 +    return FALSE;
    1.61 +}
    1.62 +
    1.63 +gboolean hasRequiredGLExtensions( ) 
    1.64 +{
    1.65 +    int i;
    1.66 +    gboolean isOK = TRUE;
    1.67 +
    1.68 +    for( i=0; required_extensions[i] != NULL; i++ ) {
    1.69 +	if( !isGLExtensionSupported(required_extensions[i]) ) {
    1.70 +	    ERROR( "Required OpenGL extension not supported: %s", required_extensions[i] );
    1.71 +	    isOK = FALSE;
    1.72 +	}
    1.73 +    }
    1.74 +    return isOK;
    1.75 +}
    1.76 +
    1.77 +
    1.78 +gboolean gl_display_frame_buffer( frame_buffer_t frame )
    1.79 +{
    1.80 +    GLenum type = colour_formats[frame->colour_format].type;
    1.81 +    GLenum format = colour_formats[frame->colour_format].format;
    1.82 +    int bpp = colour_formats[frame->colour_format].bpp;
    1.83 +    GLint texid;
    1.84 +
    1.85 +    glViewport( 0, 0, video_width, video_height );
    1.86 +    glMatrixMode(GL_PROJECTION);
    1.87 +    glLoadIdentity();
    1.88 +    glOrtho( 0, video_width, video_height, 0, 0, -65535 );
    1.89 +    glMatrixMode(GL_MODELVIEW);
    1.90 +    glLoadIdentity();
    1.91 +    
    1.92 +    /* Disable everything */
    1.93 +    glDisable( GL_TEXTURE_2D );
    1.94 +    glDisable( GL_ALPHA_TEST );
    1.95 +    glDisable( GL_DEPTH_TEST );
    1.96 +    glDisable( GL_SCISSOR_TEST );
    1.97 +    glDisable( GL_CULL_FACE );
    1.98 +
    1.99 +    float scale = ((float)video_height) / frame->height;
   1.100 +    int rowstride = (frame->rowstride / bpp) - frame->width;
   1.101 +    
   1.102 +    
   1.103 +    /*
   1.104 +    glGenTextures( 1, &texid );
   1.105 +    glBindTexture( GL_TEXTURE_2D, texid );
   1.106 +    glTexImage2D( GL_TEXTURE_2D, 0, colour_formats[frame->colour_format].int_format,
   1.107 +		  frame->width, frame->height, 0, format, type, frame->data );
   1.108 +    glBegin( GL_QUADS );
   1.109 +    glTexCoord2i( 0, 1.0 );
   1.110 +    glVertex2f( 0.0, 0.0 );
   1.111 +    glTexCoord2i( 1.0, 1.0 );
   1.112 +    glVertex2f( frame->width, 0.0 );
   1.113 +    glTexCoord2i( 1.0, 0.0 );
   1.114 +    glVertex2f( frame->width, frame->height );
   1.115 +    glTexCoord2i( 0, 0.0 );
   1.116 +    glVertex2f( 0.0, frame->height );
   1.117 +    glEnd();
   1.118 +    glDeleteTextures( 1, &texid );
   1.119 +    */
   1.120 +    glRasterPos2i( 0, 0 );
   1.121 +    glPixelZoom( 1.0f, -scale );
   1.122 +    glPixelStorei( GL_UNPACK_ROW_LENGTH, rowstride );
   1.123 +    glDrawPixels( frame->width, frame->height, format, type,
   1.124 +		  frame->data );
   1.125 +    
   1.126 +    glFlush();
   1.127 +    return TRUE;
   1.128 +}
   1.129 +
   1.130 +gboolean gl_display_blank( uint32_t colour )
   1.131 +{
   1.132 +    glViewport( 0, 0, video_width, video_height );
   1.133 +    glMatrixMode( GL_PROJECTION );
   1.134 +    glLoadIdentity();
   1.135 +    glOrtho( 0, video_width, video_height, 0, 0, -65535 );
   1.136 +    glMatrixMode(GL_MODELVIEW);
   1.137 +    glLoadIdentity();
   1.138 +    glColor3b( (colour >> 16) & 0xFF, (colour >> 8) & 0xFF, colour & 0xFF );
   1.139 +    glRecti(0,0, video_width, video_height );
   1.140 +    glFlush();
   1.141 +    return TRUE;
   1.142 +}
   1.143 +
   1.144 +/**
   1.145 + * Generic GL read_render_buffer. This function assumes that the caller
   1.146 + * has already set the appropriate glReadBuffer(); in other words, unless
   1.147 + * there's only one buffer this needs to be wrapped.
   1.148 + */
   1.149 +gboolean gl_read_render_buffer( render_buffer_t buffer, char *target ) 
   1.150 +{
   1.151 +    if( buffer->address == -1 )
   1.152 +	return FALSE;
   1.153 +    glFinish();
   1.154 +    GLenum type = colour_formats[buffer->colour_format].type;
   1.155 +    GLenum format = colour_formats[buffer->colour_format].format;
   1.156 +    int line_size = buffer->width * colour_formats[buffer->colour_format].bpp;
   1.157 +    int size = line_size * buffer->height;
   1.158 +    int rowstride = (buffer->rowstride / colour_formats[buffer->colour_format].bpp) - buffer->width;
   1.159 +    // glPixelStorei( GL_PACK_ROW_LENGTH, rowstride );
   1.160 +    
   1.161 +    glReadPixels( 0, 0, buffer->width, buffer->height, format, type, target );
   1.162 +    return TRUE;
   1.163 +}