Shader abstractions

This commit is contained in:
Ben
2019-01-13 16:27:45 +00:00
parent 459f897ef7
commit 34cb0fb1c6
4 changed files with 170 additions and 74 deletions

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@@ -7,6 +7,8 @@
#include <string>
#include <map>
#include "shader.hpp"
void GLAPIENTRY MessageCallback(GLenum source,
GLenum type,
GLuint id,
@@ -27,71 +29,6 @@ public:
bool isWindowClosed = true;
};
std::map<std::string, GLuint> VertexShaders;
std::map<std::string, GLuint> FragmentShaders;
std::map<std::string, GLuint> ShaderPrograms;
std::string readShader(std::string source) {
std::ifstream t(source);
std::string shaderCode((std::istreambuf_iterator<char>(t)),
std::istreambuf_iterator<char>());
// std::cout << shaderCode << std::endl;
return shaderCode;
}
bool loadShader(std::string shaderSource, GLenum type, std::string shader) {
const char* source = shaderSource.c_str();
if (type == GL_VERTEX_SHADER) {
GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &source, NULL);
glCompileShader(vertexShader);
GLint status;
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &status);
if (status == GL_FALSE) {
char buf[512];
glGetShaderInfoLog(vertexShader, 512, NULL, buf);
std::cerr << buf << std::endl;
return false;
}
VertexShaders[shader] = vertexShader;
std::cout << "Vertex shader at '" << shader << "' compiled..." << std::endl;
} else if (type == GL_FRAGMENT_SHADER) {
GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &source, NULL);
glCompileShader(fragmentShader);
GLint status;
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &status);
if (status == GL_FALSE) {
char buf[512];
glGetShaderInfoLog(fragmentShader, 512, NULL, buf);
std::cerr << buf << std::endl;
return false;
}
FragmentShaders[shader] = fragmentShader;
std::cout << "Fragment shader at '" << shader << "' compiled..." << std::endl;
}
return true;
}
void makeShaderProgram(std::string vert, std::string frag, std::string program) {
GLuint shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, VertexShaders[vert]);
glAttachShader(shaderProgram, FragmentShaders[frag]);
ShaderPrograms[program] = shaderProgram;
std::cout << "Shader program '" << program << "' created" << std::endl;
}
void applyShader(std::string shader) {
glLinkProgram(ShaderPrograms[shader]);
glUseProgram(ShaderPrograms[shader]);
std::cout << "Shader program '" << shader << "' applied" << std::endl;
}
int main(int argc, char** argv) {
Game* game = new Game();
SDL_Init(SDL_INIT_EVERYTHING);
@@ -152,24 +89,20 @@ int main(int argc, char** argv) {
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices[0]) * numOfVerticies, vertices, GL_STATIC_DRAW);
// Load, compile, apply and link shader programs
if (!loadShader(readShader("shaders/simple.vert"), GL_VERTEX_SHADER , "simpleVert") ||
!loadShader(readShader("shaders/simple.frag"), GL_FRAGMENT_SHADER, "simpleFrag")) {
return 0;
}
makeShaderProgram("simpleVert", "simpleFrag", "simpleProc");
applyShader("simpleProc");
Shader simpleShader;
simpleShader.load("./shaders/simple").attatch().link().use();
GLint posAttrib = glGetAttribLocation(ShaderPrograms["simpleProc"], "position");
GLint posAttrib = glGetAttribLocation(simpleShader.getProgram(), "position");
glEnableVertexAttribArray(posAttrib);
glVertexAttribPointer(posAttrib, 2, GL_FLOAT, GL_FALSE,
5*sizeof(float), 0);
GLint colAttrib = glGetAttribLocation(ShaderPrograms["simpleProc"], "colour");
GLint colAttrib = glGetAttribLocation(simpleShader.getProgram(), "colour");
glEnableVertexAttribArray(colAttrib);
glVertexAttribPointer(colAttrib, 3, GL_FLOAT, GL_FALSE,
5*sizeof(float), (void*)(2*sizeof(float)));
GLint triangleUniColour = glGetUniformLocation(ShaderPrograms["simpleProc"], "triangleColour");
GLint triangleUniColour = glGetUniformLocation(simpleShader.getProgram(), "triangleColour");
glUniform3f(triangleUniColour, 0.2f, 0.8f, 0.3f);
SDL_Event event;

125
OpenGL/cube/src/shader.cpp Normal file
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@@ -0,0 +1,125 @@
#include "shader.hpp"
#include <iostream>
#include <fstream>
Shader::Shader() {
m_program = glCreateProgram();
}
Shader& Shader::use() {
glUseProgram(m_program);
return *this;
}
Shader& Shader::link() {
glLinkProgram(m_program);
return *this;
}
Shader& Shader::attatch() {
glAttachShader(m_program, m_vert);
glAttachShader(m_program, m_frag);
return *this;
}
std::string readShader(std::string source) {
std::ifstream t(source);
std::string shaderCode((std::istreambuf_iterator<char>(t)),
std::istreambuf_iterator<char>());
return shaderCode;
}
Shader& Shader::load(GLenum type, std::string sourceLoc) {
const char* source = readShader(sourceLoc).c_str();
if (type == GL_VERTEX_SHADER) {
GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &source, NULL);
glCompileShader(vertexShader);
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &m_status);
if (m_status == GL_FALSE) {
char buf[512];
glGetShaderInfoLog(vertexShader, 512, NULL, buf);
std::cerr << buf << std::endl;
}
m_vert = vertexShader;
m_vertLoc = sourceLoc;
m_vertSource = (std::string)source;
std::cout << "Vertex shader at '" << sourceLoc << "' compiled..." << std::endl;
} else if (type == GL_FRAGMENT_SHADER) {
GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &source, NULL);
glCompileShader(fragmentShader);
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &m_status);
if (m_status == GL_FALSE) {
char buf[512];
glGetShaderInfoLog(fragmentShader, 512, NULL, buf);
std::cerr << buf << std::endl;
}
m_frag = fragmentShader;
m_fragLoc = sourceLoc;
m_fragSource = (std::string)source;
std::cout << "Fragment shader at '" << sourceLoc << "' compiled..." << std::endl;
}
return *this;
}
Shader& Shader::load(std::string sourceLoc) {
m_vertLoc = sourceLoc + ".vert";
m_fragLoc = sourceLoc + ".frag";
m_vertSource = readShader(m_vertLoc);
m_fragSource = readShader(m_fragLoc);
m_vert = glCreateShader(GL_VERTEX_SHADER);
m_frag = glCreateShader(GL_FRAGMENT_SHADER);
const char* vertSource = m_vertSource.c_str();
glShaderSource(m_vert, 1, &vertSource, NULL);
glCompileShader(m_vert);
const char* fragSource = m_fragSource.c_str();
glShaderSource(m_frag, 1, &fragSource, NULL);
glCompileShader(m_frag);
glGetShaderiv(m_vert, GL_COMPILE_STATUS, &m_status);
if (m_status == GL_FALSE) {
char buf[512];
glGetShaderInfoLog(m_vert, 512, NULL, buf);
std::cerr << buf << std::endl;
}
glGetShaderiv(m_frag, GL_COMPILE_STATUS, &m_status);
if (m_status == GL_FALSE) {
char buf[512];
glGetShaderInfoLog(m_frag, 512, NULL, buf);
std::cerr << buf << std::endl;
}
std::cout << "Vertex shader at '" << m_vertLoc << "' compiled..." << std::endl;
std::cout << "Fragment shader at '" << m_fragLoc << "' compiled..." << std::endl;
return *this;
}
GLuint Shader::getProgram() {
return m_program;
}
GLuint Shader::getVertex() {
return m_vert;
}
GLuint Shader::getFragment() {
return m_frag;
}
Shader::~Shader() {
glDeleteProgram(m_program);
glDeleteShader(m_vert);
glDeleteShader(m_frag);
}

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@@ -0,0 +1,38 @@
#ifndef _SHADER_H_
#define _SHADER_H_
#include <GL/glew.h>
#include <string>
class Shader {
public:
Shader();
Shader& use();
Shader& link();
Shader& attatch();
Shader& load(GLenum type, std::string sourceLoc);
Shader& load(std::string sourceLoc);
GLuint getProgram();
GLuint getVertex();
GLuint getFragment();
virtual ~Shader();
private:
Shader(Shader const &) = delete;
Shader & operator=(Shader const &) = delete;
GLuint m_program;
GLuint m_vert;
GLuint m_frag;
std::string m_vertSource;
std::string m_fragSource;
std::string m_vertLoc;
std::string m_fragLoc;
GLint m_status;
};
#endif