4 * Common GL code that doesn't depend on a specific implementation
6 * Copyright (c) 2005 Nathan Keynes.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
22 #include "pvr2/pvr2.h"
23 #include "drivers/gl_common.h"
25 extern uint32_t video_width, video_height;
27 char *required_extensions[] = { "GL_EXT_framebuffer_object", NULL };
30 * Test if a specific extension is supported. From opengl.org
31 * @param extension extension name to check for
32 * @return TRUE if supported, otherwise FALSE.
34 gboolean isGLExtensionSupported( const char *extension )
36 const GLubyte *extensions = NULL;
38 GLubyte *where, *terminator;
40 /* Extension names should not have spaces. */
41 where = (GLubyte *) strchr(extension, ' ');
42 if (where || *extension == '\0')
44 extensions = glGetString(GL_EXTENSIONS);
45 /* It takes a bit of care to be fool-proof about parsing the
46 OpenGL extensions string. Don't be fooled by sub-strings,
50 where = (GLubyte *) strstr((const char *) start, extension);
53 terminator = where + strlen(extension);
54 if (where == start || *(where - 1) == ' ')
55 if (*terminator == ' ' || *terminator == '\0')
62 gboolean hasRequiredGLExtensions( )
67 for( i=0; required_extensions[i] != NULL; i++ ) {
68 if( !isGLExtensionSupported(required_extensions[i]) ) {
69 ERROR( "Required OpenGL extension not supported: %s", required_extensions[i] );
77 * Reset the gl state to simple orthographic projection with
78 * texturing, alpha/depth/scissor/cull tests disabled.
82 glViewport( 0, 0, video_width, video_height );
83 glMatrixMode(GL_PROJECTION);
85 glOrtho( 0, video_width, video_height, 0, 0, -65535 );
86 glMatrixMode(GL_MODELVIEW);
88 glDisable( GL_TEXTURE_2D );
89 glDisable( GL_ALPHA_TEST );
90 glDisable( GL_DEPTH_TEST );
91 glDisable( GL_SCISSOR_TEST );
92 glDisable( GL_CULL_FACE );
93 glDrawBuffer( GL_FRONT );
96 void gl_display_render_buffer( render_buffer_t buffer )
98 gl_texture_window( buffer->width, buffer->height, buffer->buf_id, buffer->inverted );
101 void gl_texture_window( int width, int height, int tex_id, gboolean inverted )
105 top = ((float)height);
109 bottom = ((float)height);
112 /* Reset display parameters */
116 int x1=0,y1=0,x2=video_width,y2=video_height;
118 int ah = video_width * 0.75;
120 if( ah > video_height ) {
121 int w = (video_height/0.75);
122 x1 = (video_width - w)/2;
128 glVertex2f( x1, video_height );
129 glVertex2f( 0, video_height);
131 glVertex2f( video_width, 0 );
132 glVertex2f( video_width, video_height );
133 glVertex2f( x2, video_height);
135 } else if( ah < video_height ) {
136 y1 = (video_height - ah)/2;
140 glVertex2f( video_width, 0 );
141 glVertex2f( video_width, y1 );
144 glVertex2f( video_width, y2 );
145 glVertex2f( video_width, video_height );
146 glVertex2f( 0, video_height );
150 /* Render the textured rectangle */
151 glEnable( GL_TEXTURE_RECTANGLE_ARB );
152 glBindTexture( GL_TEXTURE_RECTANGLE_ARB, tex_id );
153 glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE );
154 glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
155 glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
156 glEnable( GL_BLEND );
157 glBlendFunc( GL_ONE, GL_ZERO );
159 glTexCoord2f( 0, top );
160 glVertex2f( x1, y1 );
161 glTexCoord2f( ((float)width), top );
162 glVertex2f( x2, y1 );
163 glTexCoord2f( ((float)width), bottom );
164 glVertex2f( x2, y2 );
165 glTexCoord2f( 0, bottom );
166 glVertex2f( x1, y2 );
168 glDisable( GL_TEXTURE_RECTANGLE_ARB );
172 gboolean gl_load_frame_buffer( frame_buffer_t frame, int tex_id )
174 GLenum type = colour_formats[frame->colour_format].type;
175 GLenum format = colour_formats[frame->colour_format].format;
176 int bpp = colour_formats[frame->colour_format].bpp;
177 int rowstride = (frame->rowstride / bpp) - frame->width;
179 glPixelStorei( GL_UNPACK_ROW_LENGTH, rowstride );
180 glBindTexture( GL_TEXTURE_RECTANGLE_ARB, tex_id );
181 glTexSubImage2D( GL_TEXTURE_RECTANGLE_ARB, 0, 0,0,
182 frame->width, frame->height, format, type, frame->data );
186 gboolean gl_display_blank( uint32_t colour )
189 glColor3ub( (colour >> 16) & 0xFF, (colour >> 8) & 0xFF, colour & 0xFF );
190 glRecti(0,0, video_width, video_height );
196 * Generic GL read_render_buffer. This function assumes that the caller
197 * has already set the appropriate glReadBuffer(); in other words, unless
198 * there's only one buffer this needs to be wrapped.
200 gboolean gl_read_render_buffer( unsigned char *target, render_buffer_t buffer,
201 int rowstride, int colour_format )
204 GLenum type = colour_formats[colour_format].type;
205 GLenum format = colour_formats[colour_format].format;
206 // int line_size = buffer->width * colour_formats[colour_format].bpp;
207 // int size = line_size * buffer->height;
208 int glrowstride = (rowstride / colour_formats[colour_format].bpp) - buffer->width;
209 glPixelStorei( GL_PACK_ROW_LENGTH, glrowstride );
211 glReadPixels( 0, 0, buffer->width, buffer->height, format, type, target );
.