nkeynes@635: /**
nkeynes@635:  * $Id$
nkeynes@635:  *
nkeynes@635:  * GLSL shader loader/unloader. Current version assumes there's exactly
nkeynes@635:  * 1 shader program that's used globally. This may turn out not to be the
nkeynes@635:  * most efficient approach.
nkeynes@635:  *
nkeynes@635:  * Copyright (c) 2007 Nathan Keynes.
nkeynes@635:  *
nkeynes@635:  * This program is free software; you can redistribute it and/or modify
nkeynes@635:  * it under the terms of the GNU General Public License as published by
nkeynes@635:  * the Free Software Foundation; either version 2 of the License, or
nkeynes@635:  * (at your option) any later version.
nkeynes@635:  *
nkeynes@635:  * This program is distributed in the hope that it will be useful,
nkeynes@635:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
nkeynes@635:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nkeynes@635:  * GNU General Public License for more details.
nkeynes@635:  */
nkeynes@635: 
nkeynes@635: #include "lxdream.h"
nkeynes@635: #include "display.h"
nkeynes@635: #include "pvr2/glutil.h"
nkeynes@635: 
nkeynes@635: #define MAX_ERROR_BUF 4096
nkeynes@635: 
nkeynes@635: gboolean glsl_is_supported()
nkeynes@635: {
nkeynes@635:     return isGLExtensionSupported("GL_ARB_fragment_shader") &&
nkeynes@635: 	isGLExtensionSupported("GL_ARB_vertex_shader") &&
nkeynes@635: 	isGLExtensionSupported("GL_ARB_shading_language_100");
nkeynes@635: }
nkeynes@635: 
nkeynes@635: #ifdef GL_ARB_shader_objects
nkeynes@635: static GLhandleARB glsl_program = 0, glsl_vert_shader = 0, glsl_frag_shader = 0;
nkeynes@635: 
nkeynes@635: void glsl_print_error( char *msg, GLhandleARB obj )
nkeynes@635: {
nkeynes@635:     char buf[MAX_ERROR_BUF];
nkeynes@635:     GLsizei length;
nkeynes@635:     glGetInfoLogARB( obj, sizeof(buf), &length, buf );
nkeynes@635:     ERROR( "%s: %s", msg, buf );
nkeynes@635: }
nkeynes@635: 
nkeynes@635: gboolean glsl_check_shader_error( char *msg, GLhandleARB obj )
nkeynes@635: {
nkeynes@635:     GLint value;
nkeynes@635: 
nkeynes@635:     glGetObjectParameterivARB(obj, GL_OBJECT_COMPILE_STATUS_ARB, &value);
nkeynes@635:     if( value == 0 ) {
nkeynes@635: 	glsl_print_error(msg, obj);
nkeynes@635: 	return FALSE;
nkeynes@635:     }
nkeynes@635:     return TRUE;
nkeynes@635: }
nkeynes@635: 
nkeynes@635: gboolean glsl_check_program_error( char *msg, GLhandleARB obj )
nkeynes@635: {
nkeynes@635:     if( glGetError() != GL_NO_ERROR ) {
nkeynes@635: 	glsl_print_error(msg, obj);
nkeynes@635:     }
nkeynes@635:     return TRUE;
nkeynes@635: }
nkeynes@635: 
nkeynes@635: 
nkeynes@635: gboolean glsl_load_shaders( const char *vertex_src, const char *fragment_src )
nkeynes@635: {
nkeynes@635:     gboolean vsok = TRUE, fsok = TRUE, pok = FALSE;
nkeynes@635: 
nkeynes@635:     if( vertex_src == NULL && fragment_src == NULL ) {
nkeynes@635: 	return TRUE; // nothing to do
nkeynes@635:     }
nkeynes@635: 
nkeynes@635:     glsl_program = glCreateProgramObjectARB();
nkeynes@635: 
nkeynes@635:     if( vertex_src != NULL ) {
nkeynes@635: 	glsl_vert_shader = glCreateShaderObjectARB(GL_VERTEX_SHADER_ARB);
nkeynes@635: 	glShaderSourceARB( glsl_vert_shader, 1, &vertex_src, NULL );
nkeynes@635: 	glCompileShaderARB(glsl_vert_shader);
nkeynes@635: 	vsok = glsl_check_shader_error("Failed to compile vertex shader", glsl_vert_shader);
nkeynes@635:     }
nkeynes@635:     if( fragment_src != NULL ) {
nkeynes@635: 	glsl_frag_shader = glCreateShaderObjectARB(GL_FRAGMENT_SHADER_ARB);
nkeynes@635: 	glShaderSourceARB( glsl_frag_shader, 1, &fragment_src, NULL );
nkeynes@635: 	glCompileShaderARB(glsl_frag_shader);
nkeynes@635: 	fsok = glsl_check_shader_error("Failed to compile fragment shader", glsl_frag_shader);
nkeynes@635:     }
nkeynes@635: 
nkeynes@635:     if( vsok && fsok ) {
nkeynes@635: 	if( vertex_src != NULL ) {
nkeynes@635: 	    glAttachObjectARB(glsl_program, glsl_vert_shader);
nkeynes@635: 	}
nkeynes@635: 	if( fragment_src != NULL ) {
nkeynes@635: 	    glAttachObjectARB(glsl_program, glsl_frag_shader);
nkeynes@635: 	}
nkeynes@635: 	glLinkProgramARB(glsl_program);
nkeynes@635: 	pok = glsl_check_program_error( "Failed to link shader program", glsl_program );
nkeynes@635:     }
nkeynes@635:     if( pok ) {
nkeynes@635: 	glUseProgramObjectARB(glsl_program);
nkeynes@635: 	pok = glsl_check_program_error( "Failed to apply shader program", glsl_program );
nkeynes@635:     } else {
nkeynes@635: 	glsl_unload_shaders();
nkeynes@635:     }
nkeynes@635:     return pok;
nkeynes@635: }
nkeynes@635: 
nkeynes@669: void glsl_enable_shaders(gboolean en)
nkeynes@635: {
nkeynes@635:     if( glsl_program != 0 ) {
nkeynes@635: 	if( en ) {
nkeynes@635: 	    glUseProgramObjectARB(glsl_program);
nkeynes@635: 	} else {
nkeynes@635: 	    glUseProgramObjectARB(0);
nkeynes@635: 	}
nkeynes@635:     }
nkeynes@635: }
nkeynes@635: 
nkeynes@635: void glsl_unload_shaders(void)
nkeynes@635: {
nkeynes@635:     glUseProgramObjectARB(0);
nkeynes@635:     glDetachObjectARB(glsl_program, glsl_vert_shader);
nkeynes@635:     glDetachObjectARB(glsl_program, glsl_frag_shader);
nkeynes@635:     glDeleteObjectARB(glsl_program);
nkeynes@635:     glDeleteObjectARB(glsl_vert_shader);
nkeynes@635:     glDeleteObjectARB(glsl_frag_shader);
nkeynes@635: }
nkeynes@635: 
nkeynes@656: #elif HAVE_OPENGL_SHADER
nkeynes@635: static GLuint glsl_program = 0, glsl_vert_shader = 0, glsl_frag_shader = 0;
nkeynes@635: 
nkeynes@635: gboolean glsl_check_shader_error( char *msg, GLuint shader )
nkeynes@635: {
nkeynes@635:     GLint value;
nkeynes@635: 
nkeynes@635:     glGetShaderiv( shader, GL_COMPILE_STATUS, &value );
nkeynes@635:     if( value == 0 ) {
nkeynes@635: 	char buf[MAX_ERROR_BUF];
nkeynes@635: 	GLsizei length;
nkeynes@635: 	glGetShaderInfoLog( shader, sizeof(buf), &length, buf );
nkeynes@635: 	ERROR( "%s: %s", msg, buf );
nkeynes@635: 	return FALSE;
nkeynes@635:     }
nkeynes@635:     return TRUE;
nkeynes@635: }
nkeynes@635: gboolean glsl_check_program_error( char *msg, GLuint program )
nkeynes@635: {
nkeynes@635:     if( glGetError() != GL_NO_ERROR ) {
nkeynes@635: 	char buf[MAX_ERROR_BUF];
nkeynes@635: 	GLsizei length;
nkeynes@635: 	glGetProgramInfoLog( program, sizeof(buf), &length, buf );
nkeynes@635: 	ERROR( "%s: %s", msg, buf );
nkeynes@635: 	return FALSE;
nkeynes@635:     }
nkeynes@635:     return TRUE;
nkeynes@635: }
nkeynes@635: 
nkeynes@635: gboolean glsl_load_shaders( const char *vertex_src, const char *fragment_src )
nkeynes@635: {
nkeynes@635:     gboolean vsok = TRUE, fsok = TRUE, pok = FALSE;
nkeynes@635: 
nkeynes@635:     if( vertex_src == NULL && fragment_src == NULL ) {
nkeynes@635: 	return TRUE;
nkeynes@635:     }
nkeynes@635: 
nkeynes@635:     glsl_program = glCreateProgram();
nkeynes@635: 
nkeynes@635:     if( vertex_src != NULL ) {
nkeynes@635: 	glsl_vert_shader = glCreateShader(GL_VERTEX_SHADER);
nkeynes@635: 	glShaderSource( glsl_vert_shader, 1, &vertex_src, NULL );
nkeynes@635: 	glCompileShader(glsl_vert_shader);
nkeynes@635: 	vsok = glsl_check_shader_error( "Failed to compile vertex shader", glsl_vert_shader );
nkeynes@635:     }
nkeynes@635:     if( fragment_src != NULL ) {
nkeynes@635: 	glsl_frag_shader = glCreateShader(GL_FRAGMENT_SHADER);
nkeynes@635: 	glShaderSource( glsl_frag_shader, 1, &fragment_src, NULL );
nkeynes@635: 	glCompileShader(glsl_frag_shader);
nkeynes@635: 	fsok = glsl_check_shader_error( "Failed to compile fragment shader", glsl_frag_shader );
nkeynes@635:     }
nkeynes@635: 
nkeynes@635:     if( vsok && fsok ) {
nkeynes@635: 	if( vertex_src != NULL ) {
nkeynes@635: 	    glAttachShader(glsl_program, glsl_vert_shader);
nkeynes@635: 	}
nkeynes@635: 	if( fragment_src != NULL ) {
nkeynes@635: 	    glAttachShader(glsl_program, glsl_frag_shader);
nkeynes@635: 	}
nkeynes@635: 	glLinkProgram(glsl_program);
nkeynes@635: 	pok = glsl_check_program_error( "Failed to link shader program", glsl_program );
nkeynes@635:     }
nkeynes@635: 
nkeynes@635:     if( pok ) {
nkeynes@635: 	glUseProgram(glsl_program);
nkeynes@635:     } else {
nkeynes@635: 	glsl_unload_shaders();
nkeynes@635:     }
nkeynes@635:     return pok;
nkeynes@635: }
nkeynes@635: 
nkeynes@635: 
nkeynes@669: void glsl_enable_shaders(gboolean en)
nkeynes@635: {
nkeynes@635:     if( glsl_program != 0 ) {
nkeynes@635: 	if( en ) {
nkeynes@635: 	    glUseProgram(glsl_program);
nkeynes@635: 	} else {
nkeynes@635: 	    glUseProgram(0);
nkeynes@635: 	}
nkeynes@635:     }
nkeynes@635: }
nkeynes@635: 
nkeynes@635: void glsl_unload_shaders(void)
nkeynes@635: {
nkeynes@635:     glUseProgram(0);
nkeynes@635:     glDetachShader(glsl_program, glsl_vert_shader);
nkeynes@635:     glDetachShader(glsl_program, glsl_frag_shader);
nkeynes@635:     glDeleteProgram(glsl_program);
nkeynes@635:     glDeleteShader(glsl_vert_shader);
nkeynes@635:     glDeleteShader(glsl_frag_shader);
nkeynes@635: }
nkeynes@656: 
nkeynes@656: #else
nkeynes@656: gboolean glsl_load_shaders( const char *vertex_src, const char *fragment_src )
nkeynes@656: {
nkeynes@656:     return FALSE;
nkeynes@656: }
nkeynes@656: 
nkeynes@656: void glsl_unload_shaders()
nkeynes@656: {
nkeynes@656: }
nkeynes@656: 
nkeynes@669: void glsl_enable_shaders( gboolean enable )
nkeynes@669: {
nkeynes@669: }
nkeynes@635: #endif