From 42de6197a6b29ef1d922c82e5bab263f1348ec03 Mon Sep 17 00:00:00 2001
From: Jon Bergli Heier <snakebite@jvnv.net>
Date: Mon, 24 May 2010 03:38:50 +0200
Subject: Rewrote shader classes to throw exceptions when errors occur.

---
 engine/shader.cpp | 76 ++++++++++++++++++++++++++++---------------------------
 engine/shader.h   | 18 ++++++-------
 2 files changed, 47 insertions(+), 47 deletions(-)

diff --git a/engine/shader.cpp b/engine/shader.cpp
index 04aa031..a0509ff 100644
--- a/engine/shader.cpp
+++ b/engine/shader.cpp
@@ -1,11 +1,21 @@
 #include <fstream>
+#include <stdexcept>
+
+#include <boost/format.hpp>
+
 #include "shader.h"
 
-bool GLBaseShader::shader_source(const char *filename) {
+static void gl_check_error(const char *msg) {
+	GLenum error = glGetError();
+	if(error != GL_NO_ERROR) {
+		throw(std::runtime_error((boost::format("%s:\n%s") % msg % gluErrorString(error)).str()));
+	}
+}
+
+void GLBaseShader::shader_source(const char *filename) {
 	std::ifstream inf(filename, std::ios_base::in);
 	if(!inf.is_open()) {
-		std::cerr << "Failed to load shader " << filename << std::endl;
-		return false;
+		throw(std::runtime_error((boost::format("Failed to load shader from file %s") % filename).str()));
 	}
 	inf.seekg(0, std::ios_base::end);
 	int length = inf.tellg();
@@ -15,77 +25,69 @@ bool GLBaseShader::shader_source(const char *filename) {
 	inf.close();
 
 	glShaderSource(shader, 1, (const GLchar**)&buffer, &length);
-	print_check_ogl_error();
+	gl_check_error("Failed to set shader source");
 	delete[] buffer;
 	glCompileShader(shader);
-	print_check_ogl_error();
 	int p;
 	glGetShaderiv(shader, GL_COMPILE_STATUS, &p);
 	if(p == 0) {
-		std::cerr << "Failed to compile shader:" << std::endl;
 		char log[0xffff];
 		int size;
 		glGetShaderInfoLog(shader, 0xffff, &size, (GLchar*)&log);
-		std::cerr << log << std::endl;
+		throw(std::runtime_error((boost::format("Failed to compile shader:\n%s") % log).str()));
 	}
-	return shader;
 }
 
-bool GLBaseShader::shader_source(std::string& filename) {
-	return shader_source(filename.c_str());
+void GLBaseShader::shader_source(std::string& filename) {
+	shader_source(filename.c_str());
 }
 
 GLBaseShader::GLBaseShader(GLenum type) {
 	shader = glCreateShader(type);
 }
 
+GLBaseShader::~GLBaseShader() {
+	glDeleteShader(shader);
+}
+
+/**
+ * GLShaderProgram
+ */
 GLShaderProgram::GLShaderProgram() {
 	program = glCreateProgram();
 }
 
-bool GLShaderProgram::attach(GLBaseShader& shader) {
+GLShaderProgram::~GLShaderProgram() {
+	glDeleteProgram(program);
+}
+
+void GLShaderProgram::attach(GLBaseShader& shader) {
 	glAttachShader(program, shader.shader);
-	return !print_check_ogl_error();
+
+	gl_check_error("Failed to attach shader to program");
 }
 
-bool GLShaderProgram::detach(GLBaseShader& shader) {
+void GLShaderProgram::detach(GLBaseShader& shader) {
 	glDetachShader(program, shader.shader);
-	return !print_check_ogl_error();
+
+	gl_check_error("Failed to detach shader from program");
 }
 
-bool GLShaderProgram::link() {
+void GLShaderProgram::link() {
 	glLinkProgram(program);
-	bool error = print_check_ogl_error();
+
 	int p;
 	glGetProgramiv(program, GL_LINK_STATUS, &p);
 	if(p == 0) {
-		std::cerr << "Failed to link program:" << std::endl;
 		char log[0xffff];
 		int size;
 		glGetProgramInfoLog(program, 0xffff, &size, (GLchar*)&log);
-		printf(log);
+		throw(std::runtime_error((boost::format("Failed to link program:\n%s") % log).str()));
 	}
-	return !error && p;
 }
 
-bool GLShaderProgram::use() {
-	if(!glIsProgram(program)) program = glCreateProgram();
+void GLShaderProgram::use() {
 	glUseProgram(program);
-	return !print_check_ogl_error();
-}
-
-void GLShaderProgram::remove() {
-	glDeleteProgram(program);
-}
 
-void print_ogl_error(GLenum error) {
-	unsigned char *buf = (unsigned char*)gluErrorString(error);
-	std::cerr << "OpenGL: " << buf << std::endl;
-}
-
-bool print_check_ogl_error() {
-	GLenum error = glGetError();
-	if(error != GL_NO_ERROR)
-		print_ogl_error(error);
-	return error != GL_NO_ERROR;
+	gl_check_error("Failed to use program");
 }
diff --git a/engine/shader.h b/engine/shader.h
index 012165a..d4ad263 100644
--- a/engine/shader.h
+++ b/engine/shader.h
@@ -16,11 +16,12 @@ class GLBaseShader {
 	friend class GLShaderProgram;
 
 	protected:
-		bool shader_source(const char *filename);
-		bool shader_source(std::string& filename);
+		void shader_source(const char *filename);
+		void shader_source(std::string& filename);
 		unsigned int shader;
 	public:
 		GLBaseShader(GLenum);
+		~GLBaseShader();
 };
 
 class GLVertexShader : public GLBaseShader {
@@ -42,15 +43,12 @@ class GLShaderProgram {
 		unsigned int program;
 	public:
 		GLShaderProgram();
+		~GLShaderProgram();
 
-		bool attach(GLBaseShader&);
-		bool detach(GLBaseShader&);
-		bool link();
-		bool use();
-		void remove();
+		void attach(GLBaseShader&);
+		void detach(GLBaseShader&);
+		void link();
+		void use();
 };
 
-void print_ogl_error(GLenum);
-bool print_check_ogl_error();
-
 #endif
-- 
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