Shadaersrsersdfsdf

1 files changed, 171 insertions, 0 deletions

diff --git a/src/shader_utils.cpp b/src/shader_utils.cpp
new file mode 100644
index 0000000..13b2f74
--- /dev/null
+++ b/src/shader_utils.cpp
@@ -0,0 +1,171 @@
+/**
+ * From the OpenGL Programming wikibook: http://en.wikibooks.org/wiki/OpenGL_Programming
+ * This file is in the public domain.
+ * Contributors: Sylvain Beucler, Guus Sliepen
+ */
+
+#include <iostream>
+#include <vector>
+using namespace std;
+
+#include <shader_utils.hpp>
+//#include <SDL_opengles2.h>
+
+/**
+ * Store all the file's contents in memory, useful to pass shaders
+ * source code to OpenGL.  Using SDL_RWops for Android asset support.
+ */
+char* file_read(const char* filename) {
+	SDL_RWops *rw = SDL_RWFromFile(filename, "rb");
+	if (rw == NULL) return NULL;
+
+	Sint64 res_size = SDL_RWsize(rw);
+	char* res = new char[res_size + 1];
+
+	Sint64 nb_read_total = 0, nb_read = 1;
+	char* buf = res;
+	while (nb_read_total < res_size && nb_read != 0) {
+		nb_read = SDL_RWread(rw, buf, 1, (res_size - nb_read_total));
+		nb_read_total += nb_read;
+		buf += nb_read;
+	}
+	SDL_RWclose(rw);
+	if (nb_read_total != res_size) {
+		delete[] res;
+		return NULL;
+	}
+
+	res[nb_read_total] = '\0';
+	return res;
+}
+
+/**
+ * Display compilation errors from the OpenGL shader compiler
+ */
+void print_log(GLuint object) {
+	GLint log_length = 0;
+	if (glIsShader(object)) {
+		glGetShaderiv(object, GL_INFO_LOG_LENGTH, &log_length);
+	} else if (glIsProgram(object)) {
+		glGetProgramiv(object, GL_INFO_LOG_LENGTH, &log_length);
+	} else {
+		SDL_LogMessage(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_ERROR,
+					   "printlog: Not a shader or a program");
+		return;
+	}
+
+
+	char *log = new char[log_length];
+
+	if (glIsShader(object))
+		glGetShaderInfoLog(object, log_length, NULL, log);
+	else if (glIsProgram(object))
+		glGetProgramInfoLog(object, log_length, NULL, log);
+
+	SDL_LogMessage(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_ERROR, "%s\n", log);
+}
+
+/**
+ * Compile the shader from file 'filename', with error handling
+ */
+GLuint create_shader(const char* filename, GLenum type) {
+	const char* source = file_read(filename);
+	if (source == NULL) {
+		SDL_LogMessage(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_ERROR,
+					   "Error opening %s: %s", filename, SDL_GetError());
+		return 0;
+	}
+	GLuint res = glCreateShader(type);
+	const GLchar* sources[] = {
+		// Define GLSL version
+		"#version 130\n"  // OpenGL 2.0
+		,
+		// Define default float precision for fragment shaders:
+		(type == GL_FRAGMENT_SHADER) ?
+		"#ifdef GL_FRAGMENT_PRECISION_HIGH\n"
+		"precision highp float;           \n"
+		"#else                            \n"
+		"precision mediump float;         \n"
+		"#endif                           \n"
+		: ""
+		,
+		source };
+	glShaderSource(res, 3, sources, NULL);
+	delete[] source;
+
+	glCompileShader(res);
+	GLint compile_ok = GL_FALSE;
+	glGetShaderiv(res, GL_COMPILE_STATUS, &compile_ok);
+	if (compile_ok == GL_FALSE) {
+		SDL_LogMessage(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_ERROR, "%s:\n", filename);
+		print_log(res);
+		glDeleteShader(res);
+		return 0;
+	}
+
+	return res;
+}
+
+GLuint create_program(const char *vertexfile, const char *fragmentfile) {
+	GLuint program = glCreateProgram();
+	GLuint shader;
+
+	if(vertexfile) {
+		shader = create_shader(vertexfile, GL_VERTEX_SHADER);
+		if(!shader)
+			return 0;
+		glAttachShader(program, shader);
+	}
+
+	if(fragmentfile) {
+		shader = create_shader(fragmentfile, GL_FRAGMENT_SHADER);
+		if(!shader)
+			return 0;
+		glAttachShader(program, shader);
+	}
+
+	glLinkProgram(program);
+	GLint link_ok = GL_FALSE;
+	glGetProgramiv(program, GL_LINK_STATUS, &link_ok);
+	if (!link_ok) {
+		SDL_LogMessage(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO, "glLinkProgram:");
+		print_log(program);
+		glDeleteProgram(program);
+		return 0;
+	}
+
+	return program;
+}
+
+GLint get_attrib(GLuint program, const char *name) {
+	GLint attribute = glGetAttribLocation(program, name);
+	if(attribute == -1)
+		SDL_LogMessage(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_ERROR,
+					   "Could not bind attribute %s", name);
+	return attribute;
+}
+
+GLint get_uniform(GLuint program, const char *name) {
+	GLint uniform = glGetUniformLocation(program, name);
+	if(uniform == -1)
+		SDL_LogMessage(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_ERROR,
+					   "Could not bind uniform %s", name);
+	return uniform;
+}
+
+void print_opengl_info() {
+	int major, minor, profile;
+	SDL_GL_GetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, &major);
+	SDL_GL_GetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, &minor);
+	SDL_GL_GetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, &profile);
+	const char* profile_str = "";
+	if (profile & SDL_GL_CONTEXT_PROFILE_CORE)
+		profile_str = "CORE";
+	if (profile & SDL_GL_CONTEXT_PROFILE_COMPATIBILITY)
+		profile_str = "COMPATIBILITY";
+	if (profile & SDL_GL_CONTEXT_PROFILE_ES)
+		profile_str = "ES";
+
+	SDL_LogMessage(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO,
+				   "OpenGL %d.%d %s", major, minor, profile_str);
+}