rewrite for practice.

mybox.cpp

@@ -1,29 +1,55 @@
 
 
+
 #include <glad/glad.h>
 #include <GLFW/glfw3.h>
 #include <iostream>
 #include <cassert>
+#include <string.h>
 
 #include "src/standard_ints.h"
 #include "src/lgl_callbacks.h"
 #include "src/lgl_shader_tools.h"
 
+#define SHADER_CNT 3
+
+char *shader_list[SHADER_CNT] = {
+	"vertex.vert",
+	"fragment.frag",
+	"fragment2.frag"
+};
+
+struct shader_storage {
+	u32 type;
+	bool compiled;
+	bool freed;
+	u32 h;
+};
+
+struct shader_storage shader_set[SHADER_CNT] = {
+	{GL_VERTEX_SHADER},
+	{GL_FRAGMENT_SHADER},
+	{GL_FRAGMENT_SHADER}
+};
+
+void helper_capabilitiesCheck() {
+	i32 numAttrs;
+	glGetIntegerv(GL_MAX_VERTEX_ATTRIBS, &numAttrs);
+	std::cout << "Maximum number of vertex attributes for this hardware: " 
+		<< numAttrs << std::endl;
+}
+
 int main(void) {
+	std::cout << "Hello Shaders." << std::endl;
 
-	std::cout << "Hello World." << std::endl;
-
-	// Setup GLFW context
 	glfwInit();
 
-	// Establish 4.2 GL requirement
 	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
 	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
 	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
 
-	// Build the winodw
+	GLFWwindow *window = glfwCreateWindow(960, 400,
-	GLFWwindow *window = glfwCreateWindow(960, 400, 
+		"Hello Shader", NULL, NULL);
-		"Hello MyBox", NULL, NULL);
 	glfwSetWindowPos(window, 140, 1000);
 
 	if (window == NULL) {
@@ -33,99 +59,69 @@ int main(void) {
 	}
 
 	glfwMakeContextCurrent(window);
-	// Set the resize callback;
 	glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
-	// Setup the glad loader
 	if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
 		std::cout << "Failed to initalize GLAD." << std::endl;
+		glfwTerminate();
 		return -1;
 	}
 
+	helper_capabilitiesCheck();
+
 	/* ====================================================================== */
 	/* ====================================================================== */
 	/* ====================================================================== */
 	i32 success;
-	char infoLog[512];
+	char debug_msg[512];
+	GLchar *shdr_source;
 
-	// Create the vertex shader
+	for (u32 i = 0; i < SHADER_CNT; i++) {
-	GLchar *shdr_src_vertex;
+		shader_set[i].h = glCreateShader(shader_set[i].type);
-	readshader("vertex.vert", &shdr_src_vertex);
+		readshader(shader_list[i], &shdr_source);
-	u32 vertexShader = glCreateShader(GL_VERTEX_SHADER);
+		glShaderSource(shader_set[i].h, 1, &shdr_source, NULL);
-	glShaderSource(vertexShader, 1, &shdr_src_vertex, NULL);
+		glCompileShader(shader_set[i].h);
-	glCompileShader(vertexShader);
+		glGetShaderiv(shader_set[i].h, GL_COMPILE_STATUS, &success);
-	glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
+		freeshader(shdr_source);
-	freeshader(shdr_src_vertex);
+		if (!success) {
-
+			glGetShaderInfoLog(shader_set[i].h, 512, NULL, debug_msg);
-	if (!success) {
+			std::cerr << "ERROR SHADER::Compilation Failed for shader: \n\t" <<
-		glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
+				shader_list[i] << std::endl;
-		std::cout << "ERROR SHADER::VERTEX::Compilation Failed\n" << 
+			return -1;
-			infoLog << std::endl;
+		} else {
-		return -1;
+			shader_set[i].compiled = true;
+		}
 	}
 
-	// Create the fragment shader
+	// Next, generate the shader programs
-	GLchar *shdr_src_fragment;
+	u32 shaderProgram[2];
-	readshader("fragment.frag", &shdr_src_fragment);
+	for (u32 i = 0; i < 2; i++) {
-	u32 fragmentShader[2] = {
+		shaderProgram[i] = glCreateProgram();
-		glCreateShader(GL_FRAGMENT_SHADER),
+		glAttachShader(shaderProgram[i], shader_set[0].h);
-		glCreateShader(GL_FRAGMENT_SHADER)
+	}
-	};
+	glAttachShader(shaderProgram[0], shader_set[1].h);
-	glShaderSource(fragmentShader[0], 1, &shdr_src_fragment, NULL);
+	glAttachShader(shaderProgram[1], shader_set[2].h);
-	glCompileShader(fragmentShader[0]);
+	for (u32 i = 0; i < 2; i++) {
-	glGetShaderiv(fragmentShader[0], GL_COMPILE_STATUS, &success);
+		glLinkProgram(shaderProgram[i]);
-	freeshader(shdr_src_fragment);
+		glGetProgramiv(shaderProgram[i], GL_LINK_STATUS, &success);
-	if (!success) {
+		if (!success) {
-		glGetShaderInfoLog(fragmentShader[0], 512, NULL, infoLog);
+			glGetProgramInfoLog(shaderProgram[i], 512, NULL, debug_msg);
-		std::cout << "ERROR SHADER::FRAGMENT::Compilation Failed\n" << 
+			std::cout << "ERROR SHADER::Linking Failed\n" << 
-			infoLog << std::endl;
+				debug_msg << std::endl;
-		return -1;
+			return -1;
+		}
 	}
 
-	readshader("fragment2.frag", &shdr_src_fragment);
+	for (u32 i = 0; i < SHADER_CNT; i++) {
-	glShaderSource(fragmentShader[1], 1, &shdr_src_fragment, NULL);
+		if (shader_set[i].compiled && !shader_set[i].freed) {
-	glCompileShader(fragmentShader[1]);
+			glDeleteShader(shader_set[i].h);
-	glGetShaderiv(fragmentShader[1], GL_COMPILE_STATUS, &success);
+			shader_set[i].freed = true;
-	freeshader(shdr_src_fragment);
+		}
-	if (!success) {
-		glGetShaderInfoLog(fragmentShader[1], 512, NULL, infoLog);
-		std::cout << "ERROR SHADER::FRAGMENT::Compilation Failed\n" << 
-			infoLog << std::endl;
-		return -1;
 	}
 
-	// Create the shader program
-	u32 shaderProgram[2] = {glCreateProgram(), glCreateProgram()};
-	glAttachShader(shaderProgram[0], vertexShader);
-	glAttachShader(shaderProgram[1], vertexShader);
-	glAttachShader(shaderProgram[0], fragmentShader[0]);
-	glAttachShader(shaderProgram[1], fragmentShader[1]);
-
-	glLinkProgram(shaderProgram[0]);
-	glGetProgramiv(shaderProgram[0], GL_LINK_STATUS, &success);
-	if (!success) {
-		glGetProgramInfoLog(shaderProgram[0], 512, NULL, infoLog);
-		std::cout << "ERROR SHADER::PROGRAM::Linking Failed\n" << 
-			infoLog << std::endl;
-		return -1;
-	}
-	glLinkProgram(shaderProgram[1]);
-	glGetProgramiv(shaderProgram[1], GL_LINK_STATUS, &success);
-	if (!success) {
-		glGetProgramInfoLog(shaderProgram[1], 512, NULL, infoLog);
-		std::cout << "ERROR SHADER::PROGRAM::Linking Failed\n" << 
-			infoLog << std::endl;
-		return -1;
-	}
-
-	// Free the old shader bits
-	glDeleteShader(vertexShader);
-	glDeleteShader(fragmentShader[0]);
-	glDeleteShader(fragmentShader[1]);
-
 	/* ====================================================================== */
 	/* ====================================================================== */
-
+	/* ====================================================================== */
 	// Define the vertex shader dat.
 	f32 vertices_1[] = {
 		-0.9f, -0.66f, 0.0f,
@@ -133,82 +129,61 @@ int main(void) {
 		-0.50f, +0.66f, 0.0f
 	};
 	f32 vertices_2[sizeof(vertices_1)/sizeof(f32)];
-	for (u32 i = 0; i < sizeof(vertices_1)/sizeof(f32); i++) {
+	memcpy(vertices_2, vertices_1, sizeof(vertices_1));
-		if (i % 3 == 0) {
+	for (u32 i = 0; i < sizeof(vertices_1)/sizeof(f32); i+=3) {
-			vertices_2[i] = -1*vertices_1[i];
+		vertices_2[i] *= -1;
-		} else {
-			vertices_2[i] = vertices_1[i];
-		}
 	}
+
+	f32 *vert_ptr[2];
+	vert_ptr[0] = vertices_1;
+	vert_ptr[1] = vertices_2;
+
 	u32 indicies[] {
 		0, 1, 2,	// t1
 	};
-	u32 VAO[2]; // Vertex Array Object refernce number
-	glGenVertexArrays(2, VAO); // ask the GPU for a reference for one buffer
-	u32 VBO[2]; // Vertex Buffer Object refernce number
-	glGenBuffers(2, VBO); // ask the GPU for a reference for one buffer
-	u32 EBO; // 
-	glGenBuffers(1, &EBO); // ask the gpu for a reference for one buffer
-	
-	// Bind VAO, meaning we 
-	glBindVertexArray(VAO[0]); 
-	// Tell the GPU subsequent calls to modify buffers apply to this buffer, 
-	// namely, the VBO buffer.
-	glBindBuffer(GL_ARRAY_BUFFER, VBO[0]);
-	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices_1), vertices_1, GL_STATIC_DRAW);
-	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3*sizeof(f32), (void *)0);
-	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
-	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indicies), indicies, GL_STATIC_DRAW);
-	// For the current Generic Vertex Attirbute Array object (VAO), indicate
-	// what index we should be starting in for subsequent draw calls.
-	glEnableVertexAttribArray(0);
 
-	glBindVertexArray(VAO[1]); 
+	u32 VAOs[2];
-	glBindBuffer(GL_ARRAY_BUFFER, VBO[1]);
+	glGenVertexArrays(2, VAOs);
-	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices_2), vertices_2, GL_STATIC_DRAW);
+	u32 VBOs[2];
-	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3*sizeof(f32), (void *)0);
+	glGenBuffers(2, VBOs);
-	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
+	u32 EBO;
-	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indicies), indicies, GL_STATIC_DRAW);
+	glGenBuffers(1, &EBO);
 
-	// For the VAO array (theoretically, but we have an array of 1), start
+	for (u32 i = 0; i < 2; i++) {
-	// at the 0th element of the VAO array.
+		glBindVertexArray(VAOs[i]);
-	glEnableVertexAttribArray(0);
+		glBindBuffer(GL_ARRAY_BUFFER, VBOs[i]);
+		glBufferData(GL_ARRAY_BUFFER, sizeof(vertices_1), vert_ptr[i], GL_STATIC_DRAW);
+		glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3*sizeof(f32), (void *)0);
+		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
+		glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indicies), indicies, GL_STATIC_DRAW);
 
-	// Setup the indexing into the VBO data. The EBO is the indirection buffer
+		glEnableVertexAttribArray(0);
-	// that tells the GPU where to look into it's known GL_ARRAY_BUFFER object
+	}
-	// for data.
 
 	glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
-	// ??
 
-	glBindVertexArray(0); // i.e., UNBIND the vertex array.
-
-	
 	while(!glfwWindowShouldClose(window)) {
 		processInput(window);
-		
+
-		// Do some rendering
 		glClearColor(0.0f, 0.1f, 0.3f, 1.0f);
 		glClear(GL_COLOR_BUFFER_BIT);
+		
+		for (u32 i = 0; i < 2; i++) {
+			glUseProgram(shaderProgram[i]);
+			glBindVertexArray(VAOs[i]);
+			glDrawArrays(GL_TRIANGLES, 0, 3);
+		}
 
-		glUseProgram(shaderProgram[0]);
-		glBindVertexArray(VAO[0]);
-		glDrawArrays(GL_TRIANGLES, 0, 3);
-		glUseProgram(shaderProgram[1]);
-		glBindVertexArray(VAO[1]);
-		glDrawArrays(GL_TRIANGLES, 0, 3);
-		//glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_INT, 0);
-
-		// Finish up
 		glfwSwapBuffers(window);
 		glfwPollEvents();
 	}
 
-	glDeleteVertexArrays(2, VAO);
+	glDeleteVertexArrays(2, VAOs);
-	glDeleteBuffers(2, VBO);
+	glDeleteBuffers(2, VBOs);
-	glDeleteBuffers(1, &EBO);
+	glDeleteTextures(1, &EBO);
-	glDeleteProgram(shaderProgram[0]);
+	for (u32 i = 0; i < 2; i++) {
-	glDeleteProgram(shaderProgram[1]);
+		glDeleteProgram(shaderProgram[i]);
+	}
 
 	i32 xpos, ypos;
 	glfwGetWindowPos(window, &xpos, &ypos);
@@ -217,4 +192,5 @@ int main(void) {
 
 	glfwTerminate();
 	return 0;
+
 }

mybox_1.cpp

@@ -0,0 +1,220 @@
+
+
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include <iostream>
+#include <cassert>
+
+#include "src/standard_ints.h"
+#include "src/lgl_callbacks.h"
+#include "src/lgl_shader_tools.h"
+
+int main(void) {
+
+	std::cout << "Hello World." << std::endl;
+
+	// Setup GLFW context
+	glfwInit();
+
+	// Establish 4.2 GL requirement
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+
+	// Build the winodw
+	GLFWwindow *window = glfwCreateWindow(960, 400, 
+		"Hello MyBox", NULL, NULL);
+	glfwSetWindowPos(window, 140, 1000);
+
+	if (window == NULL) {
+		std::cout << "Failed to create GLFW window." << std::endl;
+		glfwTerminate();
+		return -1;
+	}
+
+	glfwMakeContextCurrent(window);
+	// Set the resize callback;
+	glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
+
+	// Setup the glad loader
+	if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
+		std::cout << "Failed to initalize GLAD." << std::endl;
+		return -1;
+	}
+
+	/* ====================================================================== */
+	/* ====================================================================== */
+	/* ====================================================================== */
+	i32 success;
+	char infoLog[512];
+
+	// Create the vertex shader
+	GLchar *shdr_src_vertex;
+	readshader("vertex.vert", &shdr_src_vertex);
+	u32 vertexShader = glCreateShader(GL_VERTEX_SHADER);
+	glShaderSource(vertexShader, 1, &shdr_src_vertex, NULL);
+	glCompileShader(vertexShader);
+	glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
+	freeshader(shdr_src_vertex);
+
+	if (!success) {
+		glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
+		std::cout << "ERROR SHADER::VERTEX::Compilation Failed\n" << 
+			infoLog << std::endl;
+		return -1;
+	}
+
+	// Create the fragment shader
+	GLchar *shdr_src_fragment;
+	readshader("fragment.frag", &shdr_src_fragment);
+	u32 fragmentShader[2] = {
+		glCreateShader(GL_FRAGMENT_SHADER),
+		glCreateShader(GL_FRAGMENT_SHADER)
+	};
+	glShaderSource(fragmentShader[0], 1, &shdr_src_fragment, NULL);
+	glCompileShader(fragmentShader[0]);
+	glGetShaderiv(fragmentShader[0], GL_COMPILE_STATUS, &success);
+	freeshader(shdr_src_fragment);
+	if (!success) {
+		glGetShaderInfoLog(fragmentShader[0], 512, NULL, infoLog);
+		std::cout << "ERROR SHADER::FRAGMENT::Compilation Failed\n" << 
+			infoLog << std::endl;
+		return -1;
+	}
+
+	readshader("fragment2.frag", &shdr_src_fragment);
+	glShaderSource(fragmentShader[1], 1, &shdr_src_fragment, NULL);
+	glCompileShader(fragmentShader[1]);
+	glGetShaderiv(fragmentShader[1], GL_COMPILE_STATUS, &success);
+	freeshader(shdr_src_fragment);
+	if (!success) {
+		glGetShaderInfoLog(fragmentShader[1], 512, NULL, infoLog);
+		std::cout << "ERROR SHADER::FRAGMENT::Compilation Failed\n" << 
+			infoLog << std::endl;
+		return -1;
+	}
+
+	// Create the shader program
+	u32 shaderProgram[2] = {glCreateProgram(), glCreateProgram()};
+	glAttachShader(shaderProgram[0], vertexShader);
+	glAttachShader(shaderProgram[1], vertexShader);
+	glAttachShader(shaderProgram[0], fragmentShader[0]);
+	glAttachShader(shaderProgram[1], fragmentShader[1]);
+
+	glLinkProgram(shaderProgram[0]);
+	glGetProgramiv(shaderProgram[0], GL_LINK_STATUS, &success);
+	if (!success) {
+		glGetProgramInfoLog(shaderProgram[0], 512, NULL, infoLog);
+		std::cout << "ERROR SHADER::PROGRAM::Linking Failed\n" << 
+			infoLog << std::endl;
+		return -1;
+	}
+	glLinkProgram(shaderProgram[1]);
+	glGetProgramiv(shaderProgram[1], GL_LINK_STATUS, &success);
+	if (!success) {
+		glGetProgramInfoLog(shaderProgram[1], 512, NULL, infoLog);
+		std::cout << "ERROR SHADER::PROGRAM::Linking Failed\n" << 
+			infoLog << std::endl;
+		return -1;
+	}
+
+	// Free the old shader bits
+	glDeleteShader(vertexShader);
+	glDeleteShader(fragmentShader[0]);
+	glDeleteShader(fragmentShader[1]);
+
+	/* ====================================================================== */
+	/* ====================================================================== */
+
+	// Define the vertex shader dat.
+	f32 vertices_1[] = {
+		-0.9f, -0.66f, 0.0f,
+		-0.1f, -0.66f, 0.0f,
+		-0.50f, +0.66f, 0.0f
+	};
+	f32 vertices_2[sizeof(vertices_1)/sizeof(f32)];
+	for (u32 i = 0; i < sizeof(vertices_1)/sizeof(f32); i++) {
+		if (i % 3 == 0) {
+			vertices_2[i] = -1*vertices_1[i];
+		} else {
+			vertices_2[i] = vertices_1[i];
+		}
+	}
+	u32 indicies[] {
+		0, 1, 2,	// t1
+	};
+	u32 VAO[2]; // Vertex Array Object refernce number
+	glGenVertexArrays(2, VAO); // ask the GPU for a reference for one buffer
+	u32 VBO[2]; // Vertex Buffer Object refernce number
+	glGenBuffers(2, VBO); // ask the GPU for a reference for one buffer
+	u32 EBO; // 
+	glGenBuffers(1, &EBO); // ask the gpu for a reference for one buffer
+	
+	// Bind VAO, meaning we 
+	glBindVertexArray(VAO[0]); 
+	// Tell the GPU subsequent calls to modify buffers apply to this buffer, 
+	// namely, the VBO buffer.
+	glBindBuffer(GL_ARRAY_BUFFER, VBO[0]);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices_1), vertices_1, GL_STATIC_DRAW);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3*sizeof(f32), (void *)0);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indicies), indicies, GL_STATIC_DRAW);
+	// For the current Generic Vertex Attirbute Array object (VAO), indicate
+	// what index we should be starting in for subsequent draw calls.
+	glEnableVertexAttribArray(0);
+
+	glBindVertexArray(VAO[1]); 
+	glBindBuffer(GL_ARRAY_BUFFER, VBO[1]);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices_2), vertices_2, GL_STATIC_DRAW);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3*sizeof(f32), (void *)0);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indicies), indicies, GL_STATIC_DRAW);
+
+	// For the VAO array (theoretically, but we have an array of 1), start
+	// at the 0th element of the VAO array.
+	glEnableVertexAttribArray(0);
+
+	// Setup the indexing into the VBO data. The EBO is the indirection buffer
+	// that tells the GPU where to look into it's known GL_ARRAY_BUFFER object
+	// for data.
+
+	glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+	// ??
+
+	glBindVertexArray(0); // i.e., UNBIND the vertex array.
+
+	
+	while(!glfwWindowShouldClose(window)) {
+		processInput(window);
+		
+		// Do some rendering
+		glClearColor(0.0f, 0.1f, 0.3f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT);
+
+		glUseProgram(shaderProgram[0]);
+		glBindVertexArray(VAO[0]);
+		glDrawArrays(GL_TRIANGLES, 0, 3);
+		glUseProgram(shaderProgram[1]);
+		glBindVertexArray(VAO[1]);
+		glDrawArrays(GL_TRIANGLES, 0, 3);
+		//glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_INT, 0);
+
+		// Finish up
+		glfwSwapBuffers(window);
+		glfwPollEvents();
+	}
+
+	glDeleteVertexArrays(2, VAO);
+	glDeleteBuffers(2, VBO);
+	glDeleteBuffers(1, &EBO);
+	glDeleteProgram(shaderProgram[0]);
+	glDeleteProgram(shaderProgram[1]);
+
+	i32 xpos, ypos;
+	glfwGetWindowPos(window, &xpos, &ypos);
+	std::cout << "Closed window at pos`ition\n  (X,Y) = "
+		<< xpos << ", " << ypos << "\n" << std::endl;
+
+	glfwTerminate();
+	return 0;
+}