saved window position on startup.

tidy up moar.

exercises.

mybox.cpp

@@ -24,6 +24,8 @@ int main(void) {
 	// 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();
@@ -40,12 +42,15 @@ int main(void) {
 		return -1;
 	}
 
+	/* ====================================================================== */
+	/* ====================================================================== */
+	/* ====================================================================== */
 	i32 success;
 	char infoLog[512];
 
 	// Create the vertex shader
 	GLchar *shdr_src_vertex;
-	readshader("vertex.glsl", &shdr_src_vertex);
+	readshader("vertex.vert", &shdr_src_vertex);
 	u32 vertexShader = glCreateShader(GL_VERTEX_SHADER);
 	glShaderSource(vertexShader, 1, &shdr_src_vertex, NULL);
 	glCompileShader(vertexShader);
@@ -61,7 +66,7 @@ int main(void) {
 
 	// Create the fragment shader
 	GLchar *shdr_src_fragment;
-	readshader("fragment.glsl", &shdr_src_fragment);
+	readshader("fragment.frag", &shdr_src_fragment);
 	u32 fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
 	glShaderSource(fragmentShader, 1, &shdr_src_fragment, NULL);
 	glCompileShader(fragmentShader);
@@ -92,6 +97,9 @@ int main(void) {
 	glDeleteShader(vertexShader);
 	glDeleteShader(fragmentShader);
 
+	/* ====================================================================== */
+	/* ====================================================================== */
+
 	// Define the vertex shader dat.
 	f32 vertices[] = {
 		 0.5f,  0.5f, 0.0f,	// tr
@@ -101,32 +109,47 @@ int main(void) {
 	};
 	u32 indicies[] {
 		0, 1, 3,	// t1
-		1, 2, 3		// t2
+		2, 1, 3		// t2
 	};
-
-	u32 EBO;
-	u32 VBO;
-	u32 VAO;
-	glGenBuffers(1, &EBO);
-	glGenBuffers(1, &VBO);
-	glGenVertexArrays(1, &VAO);
+	u32 VBO; // Vertex Buffer Object refernce number
+	glGenBuffers(1, &VBO); // ask the GPU for a reference for one buffer
+	u32 VAO; // Vertex Array Object refernce number
+	glGenVertexArrays(1, &VAO); // 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
-	glBindVertexArray(VAO);
-	// copy in data to the VBO
+	// Bind VAO, meaning we 
+	glBindVertexArray(VAO); 
+	// Tell the GPU subsequent calls to modify buffers apply to this buffer, 
+	// namely, the VBO buffer.
 	glBindBuffer(GL_ARRAY_BUFFER, VBO);
+	// copy in data to the VBO. I.e. give it a pointer to some data, tell it
+	// how the entire buffer will be. sizeof(*[]) evaluates the full allocated
+	// size of the data object.
 	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-	// Setup the indexing into the VBO data
-	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
-	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indicies), indicies, GL_STATIC_DRAW);
+	// Next, tell the GPU how to use the GL_ELEMENT_ARRAY_BUfFER.
+	// In this case, read from the 0th index, 3 elements at a time as 
+	// off of the indirected GL_ARRAY_BUFFER as floating point numbers. Do not
+	// re-normalize the values (i.e., they're already normalized), and use a
+	// stride of 3xf32 as we walk through the data in the original GL_ARRAY_BUFFER
 	// Target the Atrib pointer in the VAO to the VBO inside it.
 	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3*sizeof(f32), (void *)0);
-	// STart at Zero
+	// For the VAO array (theoretically, but we have an array of 1), start
+	// at the 0th element of the VAO array.
 	glEnableVertexAttribArray(0);
 
-	glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+	// 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.
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indicies), indicies, GL_STATIC_DRAW);
+
+	glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
 	// ??
 
+	glBindVertexArray(0); // i.e., UNBIND the vertex array.
+
+	
 	while(!glfwWindowShouldClose(window)) {
 		processInput(window);
 		
@@ -136,7 +159,6 @@ int main(void) {
 
 		glUseProgram(shaderProgram);
 		glBindVertexArray(VAO);
-		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
 		glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
 
 		// Finish up
@@ -144,6 +166,16 @@ int main(void) {
 		glfwPollEvents();
 	}
 
+	glDeleteVertexArrays(1, &VAO);
+	glDeleteBuffers(1, &VBO);
+	glDeleteBuffers(1, &EBO);
+	glDeleteProgram(shaderProgram);
+
+	i32 xpos, ypos;
+	glfwGetWindowPos(window, &xpos, &ypos);
+	std::cout << "Closed window at position\n  (X,Y) = "
+		<< xpos << ", " << ypos << "\n" << std::endl;
+
 	glfwTerminate();
 	return 0;
 }

res/shaders/vertex.glsl

@@ -1,6 +0,0 @@
-#version 420 core
-layout (location = 0) in vec3 aPos;
-
-void main() {
-    gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);
-}

res/shaders/vertex.vert

@@ -0,0 +1,10 @@
+#version 420 core
+layout (location = 0) in vec3 aPos;
+//layout (location = 0) in vec2 aPos;
+//layout (location = 0) in float aPosx;
+//layout (location = 1) in float aPosy;
+//layout (location = 2) in float aPosz;
+
+void main() {
+    gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);
+}

src/lgl_callbacks.cpp

@@ -3,7 +3,7 @@
 #include "lgl_callbacks.h"
 
 void framebuffer_size_callback(
-	GLFWwindow* window, GLint width, GLint height) {
+	GLFWwindow* window, GLsizei width, GLsizei height) {
 	
 	/*
 	GLint nwidth = width - 60;

src/lgl_shader_tools.cpp

@@ -9,6 +9,9 @@
 
 #define CONST_READSHADER_MAX_FN_LEN 256
 #define CONST_READSHADER_MAX_FN_SIZE 32*1024
+
+//#define LPR__VERBOSE_SHADER
+
 int readshader(const char *fn, GLchar** pshdr_source) {
 	char shader_fn[CONST_READSHADER_MAX_FN_LEN];
 	assert(strlen(fn) + 9 < CONST_READSHADER_MAX_FN_LEN);
@@ -18,12 +21,15 @@ int readshader(const char *fn, GLchar** pshdr_source) {
 
 	snprintf(shader_fn, CONST_READSHADER_MAX_FN_LEN, "res/shaders/%s", fn);
 
-	printf("%s\n", shader_fn);
+	#ifdef LPR__VERBOSE_SHADER
+	printf("Load: '%s'\n", shader_fn);
+	#endif
 
-	if (stat(shader_fn, &status_buffer) == -1) {
+	if (stat(shader_fn, &status_buffer) != 0) {
 		printf("Failed to stat file '%s'\n", shader_fn);
-		return 0;
+		return -1;
 	}
+
 	assert(status_buffer.st_size < CONST_READSHADER_MAX_FN_SIZE-1);
 
 	FILE *fh = fopen(shader_fn, "r");
@@ -37,12 +43,13 @@ int readshader(const char *fn, GLchar** pshdr_source) {
 	assert(read_bytes < CONST_READSHADER_MAX_FN_SIZE-1);
 	shdr_source[read_bytes] = '\0';
 
+	#ifdef LPR__VERBOSE_SHADER
 	puts(shdr_source);
+	#endif
 
 	fclose(fh);
 	assert(shdr_source != NULL);
-	
-	
+		
 	*pshdr_source = shdr_source;
 	
 	return 0;