ebb721c7
 David Mayerich
new repository fo...
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#ifndef RTS_GLSHADERPROGRAM_H
#define RTS_GLSHADERPROGRAM_H
/*********************************************************
//create a shader program
rts_glShaderProgram myProgram;
//initialize
myProgram.Init();
//Attach shaders
myProgram.AttachShader(GL_FRAGMENT_SHADER, "filename.glsl");
//Compile and link
myProgram.Compile();
myProgram.Link();
myProgram.PrintLog();
//attach uniform variables
myProgram.AttachTextureMap("texture", texture);
myProgram.AttachGlobalUniform("light_intensity", &intensity);
//use the program
myProgram.BeginProgram();
//render
myProgram.EndProgram();
**********************************************************/
#include "rts_glShaderObject.h"
#include "rts_glShaderUniform.h"
#include "rts_glTextureMap.h"
#include <algorithm>
using namespace std;
class rts_glShaderProgram
{
private:
void get_uniforms()
{
GLint num_uniforms;
glGetProgramiv(id, GL_ACTIVE_UNIFORMS, &num_uniforms); //get the number of uniform variables
GLint max_name_length;
glGetProgramiv(id, GL_ACTIVE_UNIFORM_MAX_LENGTH, &max_name_length); //get the maximum uniform name length
GLchar* name_buffer = new GLchar[max_name_length]; //create a buffer to store the name
GLsizei length; //I'm not using these yet
GLint size;
GLenum type; //variable's data type
GLint location; //GPU location of the variable
for(int i=0; i<num_uniforms; i++) //create an rts_glShaderUniform structure for each variable
{
glGetActiveUniform(id, i, max_name_length, &length, &size, &type, name_buffer); //get the uniform information
location = glGetUniformLocation(id, name_buffer); //get the GPU location of the variable
//create the rts_glShaderUniform structure
rts_glShaderUniform current;
current.location = location;
current.name = name_buffer;
current.type = type;
current.p_value = NULL;
uniform_list.push_back(current);
}
}
int get_index(const char* name)
{
unsigned int size = uniform_list.size();
for(unsigned int i=0; i<size; i++)
{
if(uniform_list[i].name == name)
return i;
}
return -1;
}
string log;
public:
GLuint id;
bool linked;
vector<rts_glShaderObject> shader_list; //list of opengl shaders
vector<rts_glShaderUniform> uniform_list; //list of active uniform variables
vector<rts_glTextureMap> texture_list; //list of texture maps
rts_glShaderProgram()
{
linked = false;
id = 0;
}
void AttachShader(rts_glShaderObject shader)
{
if(id == 0)
{
Init();
}
if(shader.id == 0) //if the shader is invalid
{
log = "Shader is invalid";
return;
}
//attach the shader to the program
glAttachShader(id, shader.id); //attach the shader to the program in OpenGL
CHECK_OPENGL_ERROR
shader_list.push_back(shader); //push the shader onto our list for later access
}
//type = GL_FRAGMENT_SHADER or GL_VERTEX_SHADER
void AttachShader(GLenum type, const char* filename)
{
rts_glShaderObject shader(type, filename);
AttachShader(shader);
}
void AttachShader(GLenum type, rtsSourceCode source)
{
rts_glShaderObject shader(type, source);
AttachShader(shader);
}
void PrintLog()
{
cout<<log;
if(log.size() != 0) cout<<endl;
}
void Compile()
{
if(shader_list.size() == 0)
{
log = "No shaders to compile";
return;
}
vector<rts_glShaderObject>::iterator iter;
for(iter = shader_list.begin(); iter != shader_list.end(); iter++)
{
(*iter).Compile();
//(*iter).PrintLog();
}
}
void Link()
{
glLinkProgram(id); //link the current shader program
GLint link_status; //test to see if the link went alright
glGetProgramiv(id, GL_LINK_STATUS, &link_status);
if(link_status != GL_TRUE)
{
linked = false;
}
else
linked = true;
GLsizei length;
GLchar buffer[1000];
glGetProgramInfoLog(id, 1000, &length, buffer);
log = buffer;
get_uniforms(); //create the list of active uniform variables
}
void BeginProgram()
{
CHECK_OPENGL_ERROR
if(id == 0) //if the program is invalid, return
{
log = "Invalid program, cannot use.";
return;
}
if(!linked)
{
cout<<"Shader Program used without being linked."<<endl;
//exit(1);
}
//set up all of the texture maps
int num_textures = texture_list.size();
for(int t=0; t<num_textures; t++)
{
glActiveTexture(GL_TEXTURE0 + t);
CHECK_OPENGL_ERROR
//glEnable(texture_list[t].texture_type);
//CHECK_OPENGL_ERROR
glBindTexture(texture_list[t].texture_type, texture_list[t].name);
CHECK_OPENGL_ERROR
}
glUseProgram(id);
CHECK_OPENGL_ERROR
}
void EndProgram()
{
CHECK_OPENGL_ERROR
//return standard functionality
int num_textures = texture_list.size();
//disable all texture units
for(int t=0; t<num_textures; t++)
{
glActiveTexture(GL_TEXTURE0 + t);
glDisable(texture_list[t].texture_type);
CHECK_OPENGL_ERROR
}
//make sure that the single default texture unit is active
if(num_textures > 0)
glActiveTexture(GL_TEXTURE0);
CHECK_OPENGL_ERROR
//return to OpenGL default shading
glUseProgram(0);
CHECK_OPENGL_ERROR
}
void PrintUniforms()
{
cout<<"Shader Uniforms: "<<endl;
unsigned int i;
for(i=0; i<uniform_list.size(); i++)
{
cout<<i<<": "<<uniform_list[i].name<<" "<<uniform_list[i].location<<endl;
}
}
void AttachGlobalUniform(unsigned int index, void* param) //attaches a global variable to the indexed uniform parameter
{
uniform_list[index].p_value = param;
}
void AttachGlobalUniform(const char* name, void* param)
{
//find the index of the shader
int index = get_index(name);
if(index != -1)
AttachGlobalUniform(index, param);
else
{
string strError = "Error finding uniform variable: ";
strError += name;
cout<<strError<<endl;
}
}
void AttachTextureMap(unsigned int index, rts_glTextureMap texture) //attaches a texture map to the program
{
//if there is not a texture map assigned to the variable
if(uniform_list[index].p_value == NULL)
{
uniform_list[index].p_value = new unsigned int[1];
((unsigned int*)uniform_list[index].p_value)[0] = texture_list.size(); //set the parameter value to the index of the texture
texture_list.push_back(texture); //add the texture to the texture list
}
//if there is a texture map assigned, replace it
else
{
texture_list[((unsigned int*)(uniform_list[index].p_value))[0]] = texture;
}
}
void AttachTextureMap(const char* name, rts_glTextureMap texture)
{
int index = get_index(name);
if(index != -1) //make sure that the uniform index is valid
AttachTextureMap(index, texture);
else
cout<<"Error finding texture index. Try linking."<<endl;
}
void UpdateGlobalUniforms() //sends updated uniform information to the GPU
{
CHECK_OPENGL_ERROR
BeginProgram();
CHECK_OPENGL_ERROR
unsigned int num = uniform_list.size();
for(unsigned int i=0; i<num; i++)
uniform_list[i].submit_to_gpu();
EndProgram();
}
void Init() //Initialize the shader program
{
CHECK_OPENGL_ERROR
if(id != 0)
Clean();
id = glCreateProgram();
if(id == 0)
log = "Error getting program ID from OpenGL";
CHECK_OPENGL_ERROR
}
void Clean()
{
if(id != 0)
glDeleteProgram(id);
id = 0;
//these are allocated outside the object and can just be cleared
uniform_list.clear();
texture_list.clear();
//delete each shader from OpenGL
int num_shad = shader_list.size();
for(int i=0; i<num_shad; i++)
shader_list[i].Clean();
//clear the list
shader_list.clear();
}
};
#endif
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