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;
 }