Terrain shader lighting - work in progress.

1 files changed, 94 insertions, 0 deletions

diff --git a/shader.cpp b/shader.cpp
new file mode 100644
index 0000000..8d3493e
--- /dev/null
+++ b/shader.cpp
@@ -0,0 +1,94 @@
+#include <fstream>
+#include <stdexcept>
+
+#include <boost/format.hpp>
+
+#include "shader.h"
+
+inline 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()) {
+		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();
+	inf.seekg(0, std::ios_base::beg);
+	char *buffer = new char[length];
+	inf.read(buffer, length);
+	inf.close();
+
+	glShaderSource(shader, 1, (const GLchar**)&buffer, &length);
+	gl_check_error("Failed to set shader source");
+	delete[] buffer;
+	glCompileShader(shader);
+	int p;
+	glGetShaderiv(shader, GL_COMPILE_STATUS, &p);
+	if(p == 0) {
+		char log[0xffff];
+		int size;
+		glGetShaderInfoLog(shader, 0xffff, &size, (GLchar*)&log);
+		throw(std::runtime_error((boost::format("Failed to compile shader:\n%s") % log).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();
+}
+
+GLShaderProgram::~GLShaderProgram() {
+	glDeleteProgram(program);
+}
+
+void GLShaderProgram::attach(GLBaseShader& shader) {
+	glAttachShader(program, shader.shader);
+
+	gl_check_error("Failed to attach shader to program");
+}
+
+void GLShaderProgram::detach(GLBaseShader& shader) {
+	glDetachShader(program, shader.shader);
+
+	gl_check_error("Failed to detach shader from program");
+}
+
+void GLShaderProgram::link() {
+	glLinkProgram(program);
+	gl_check_error("linkage");
+
+	int p;
+	glGetProgramiv(program, GL_LINK_STATUS, &p);
+	if(p == 0) {
+		char log[0xffff];
+		int size;
+		glGetProgramInfoLog(program, 0xffff, &size, (GLchar*)&log);
+		throw(std::runtime_error((boost::format("Failed to link program:\n%s") % log).str()));
+	}
+}
+
+void GLShaderProgram::use() {
+	glUseProgram(program);
+
+	gl_check_error("Failed to use program");
+}