Shader stuff.

Escape-the-Dawn/ShaderProgram.h

@@ -0,0 +1,189 @@
+#ifndef ShaderProgram_h__
+#define ShaderProgram_h__
+
+#include <memory>
+#include <string>
+#include <fstream>
+#include <vector>
+
+#define _CRT_SECURE_NO_WARNINGS
+#include <GL/glew.h>
+#define GLFW_INCLUDE_GLU
+#include <GLFW/glfw3.h>
+#include <glext.h>
+
+#include "glerror.h"
+
+class Shader
+{
+public:
+	static GLuint CompileShader(GLenum shaderType, std::string fileName)
+	{
+		LOG_INFO("Compiling shader \"%s\"", fileName.c_str());
+
+		std::string shaderFile;
+		std::ifstream in(fileName, std::ios::in);
+		if(!in)
+		{
+			LOG_ERROR("Error: Failed to open shader file \"%s\"", fileName.c_str());
+			return 0;
+		}
+		in.seekg(0, std::ios::end);
+		shaderFile.resize((int)in.tellg());
+		in.seekg(0, std::ios::beg);
+		in.read(&shaderFile[0], shaderFile.size());
+		in.close();
+
+		GLuint shader = glCreateShader(shaderType);
+		if(GLERROR("glCreateShader"))
+			return 0;
+
+		const GLchar* shaderFiles = shaderFile.c_str();
+		const GLint length = shaderFile.length();
+		glShaderSource(shader, 1, &shaderFiles, &length);
+		if(GLERROR("glShaderSource"))
+			return 0;
+
+		glCompileShader(shader);
+
+		GLint compileStatus;
+		glGetShaderiv(shader, GL_COMPILE_STATUS, &compileStatus);
+		if(compileStatus != GL_TRUE)
+		{
+			LOG_ERROR("Shader compilation failed");
+			GLsizei infoLogLength;
+			glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &infoLogLength);
+			GLchar* infolog = new GLchar[infoLogLength];
+			glGetShaderInfoLog(shader, infoLogLength, &infoLogLength, infolog);
+			LOG_ERROR(infolog);
+			delete[] infolog;
+		}
+
+		if(GLERROR("glCompileShader"))
+			return 0;
+
+		return shader;
+	}
+
+	Shader(GLenum shaderType, std::string fileName)
+		: m_ShaderType(shaderType), m_FileName(fileName)
+	{
+		m_ShaderHandle = 0;
+	}
+
+	virtual ~Shader()
+	{
+		glDeleteShader(m_ShaderHandle);
+	}
+
+	GLuint Compile()
+	{
+		m_ShaderHandle = CompileShader(m_ShaderType, m_FileName);
+		return m_ShaderHandle;
+	}
+
+	GLenum GetType() const { return m_ShaderType; }
+	std::string GetFileName() const { return m_FileName; }
+	GLuint GetHandle() const { return m_ShaderHandle; }
+	bool IsCompiled() const { return m_ShaderHandle != 0; }
+
+protected:
+	GLenum m_ShaderType;
+	std::string m_FileName;
+	GLint m_ShaderHandle;
+};
+
+template <int SHADERTYPE>
+class ShaderType : public Shader
+{
+public:
+	ShaderType(std::string fileName) 
+		: Shader(SHADERTYPE, fileName) { }
+};
+
+class VertexShader : public ShaderType<GL_VERTEX_SHADER>
+{
+public:
+	VertexShader(std::string fileName)
+		: ShaderType(fileName) { }
+};
+
+class FragmentShader : public ShaderType<GL_FRAGMENT_SHADER>
+{
+public:
+	FragmentShader(std::string fileName)
+		: ShaderType(fileName) { }
+};
+
+class GeometryShader : public ShaderType<GL_GEOMETRY_SHADER>
+{
+public:
+	GeometryShader(std::string fileName)
+		: ShaderType(fileName) { }
+};
+
+class ShaderProgram
+{
+public:
+	ShaderProgram()
+	{
+		Initialize();
+	}
+	
+	ShaderProgram(std::string vertexShaderFile, std::string fragmentShaderFile)
+	{
+		AddShader(std::unique_ptr<Shader>(new VertexShader(vertexShaderFile)));
+		AddShader(std::unique_ptr<Shader>(new VertexShader(fragmentShaderFile)));
+		Initialize();
+	}
+
+	void AddShader(std::unique_ptr<Shader> shader)
+	{
+		if (!shader->IsCompiled()) {
+			shader->Compile();
+		}
+
+		m_Shaders.push_back(std::move(shader));
+	}
+
+	GLuint Link()
+	{
+		LOG_INFO("Linking shader program");
+		m_ShaderProgramHandle = glCreateProgram();
+		for (auto &shader : m_Shaders) {
+			glAttachShader(m_ShaderProgramHandle, shader->GetHandle());
+		}
+		glLinkProgram(m_ShaderProgramHandle);
+		if (GLERROR("glLinkProgram"))
+			return 0;
+
+		for (auto &shader : m_Shaders) {
+			shader.release();
+		}
+		m_Shaders.clear();
+	}
+
+	void Bind()
+	{
+		if (m_ShaderProgramHandle == 0)
+			return;
+
+		glActiveShaderProgram(0, m_ShaderProgramHandle);
+	}
+
+	void Unbind()
+	{
+		glActiveShaderProgram(0, 0);
+	}
+
+private:
+	GLuint m_ShaderProgramHandle;
+	std::vector<std::unique_ptr<Shader>> m_Shaders;
+	
+	void Initialize()
+	{
+		m_ShaderProgramHandle = 0;
+	}
+};
+
+#endif // ShaderProgram_h__