X-Git-Url: https://git.lukelau.me/?p=opengl.git;a=blobdiff_plain;f=assignment1.cpp;h=887ffb0d9a2444a8dacce433606dca42b2aeed75;hp=fd55f4e5bca90c65027b3cf4cbb0107493e5b05e;hb=refs%2Ftags%2Fassignment-1;hpb=5c9edba75c934dae9d11ae0998b92c789db3a920

diff --git a/assignment1.cpp b/assignment1.cpp
index fd55f4e..887ffb0 100644
--- a/assignment1.cpp
+++ b/assignment1.cpp
@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <fstream>
 #include <sstream>
+#include <vector>
 #ifdef __APPLE__
 #include <GL/glew.h>
 #else
@@ -14,14 +15,22 @@
 using namespace std;
 
 GLuint* vaos;
+GLuint* progIds;
+
+bool hasDrawn = false;
 
 void display() {
 	glClear(GL_COLOR_BUFFER_BIT);
 	for (int i = 0; i < 2; i++) {
+		glUseProgram(progIds[i]);
 		glBindVertexArray(vaos[i]);
 		glDrawArrays(GL_TRIANGLES, 0, 3);
 	}
 	glutSwapBuffers();
+	if (!hasDrawn) {
+		glutPostRedisplay();
+		hasDrawn = true;
+	}
 }
 
 void attachShader(GLuint progId, const char* filePath, GLenum type) {
@@ -35,7 +44,8 @@ void attachShader(GLuint progId, const char* filePath, GLenum type) {
 	ifstream file(filePath);
 	stringstream buffer;
 	buffer << file.rdbuf();
-	const char* contents = buffer.str().c_str();
+	string str = buffer.str();
+	const char* contents = str.c_str();
 
 	glShaderSource(shader, 1, (const GLchar**)&contents, NULL);
 	glCompileShader(shader);
@@ -50,11 +60,11 @@ void attachShader(GLuint progId, const char* filePath, GLenum type) {
 	glAttachShader(progId, shader);
 }
 
-GLuint compileShaders() {
+GLuint compileShaders(char* vertexShader, char* fragmentShader) {
 	GLuint progId = glCreateProgram();
 
-	attachShader(progId, "vertex.glsl", GL_VERTEX_SHADER);
-	attachShader(progId, "fragment.glsl", GL_FRAGMENT_SHADER);
+	attachShader(progId, vertexShader, GL_VERTEX_SHADER);
+	attachShader(progId, fragmentShader, GL_FRAGMENT_SHADER);
 
 	glLinkProgram(progId);
 	GLint success = 0;
@@ -66,26 +76,12 @@ GLuint compileShaders() {
 		exit(1);
 	}
 
-	glUseProgram(progId);
 	return progId;
 }
 
 #define BUFFER_OFFSET(i) ((char *)NULL + (i))
 
-GLuint* setupBuffers(GLuint progId) {
-	GLfloat vertices[2][9] = {
-		{
-			0.0f, -1.0f, 0.0f,
-			1.0f, -1.0f, 0.0f,
-			0.5f, 1.0f, 0.0f
-		},
-
-		{
-			-1.0f, -1.0f, 0.0f,
-			0.0f, -1.0f, 0.0f,
-			-0.5f, 1.0f, 0.0f
-		}
-	};
+GLuint setupBuffers(GLfloat* vertices, GLuint progId) {
 
 	GLfloat colors[] = {
 		0, 1, 0, 1,
@@ -95,11 +91,11 @@ GLuint* setupBuffers(GLuint progId) {
 
 	GLuint numVerts = 3;
 
-	GLuint vbos[2];
-	glGenBuffers(2, vbos);
+	GLuint vbo;
+	glGenBuffers(1, &vbo);
 
-	GLuint* vaos = new GLuint[2];
-	glGenVertexArrays(2, vaos);
+	GLuint vao;
+	glGenVertexArrays(1, &vao);
 
 	GLuint posId = glGetAttribLocation(progId, "vPosition");
 	GLuint colorId = glGetAttribLocation(progId, "vColor");
@@ -107,30 +103,24 @@ GLuint* setupBuffers(GLuint progId) {
 	GLuint vertsLen = numVerts * 3 * sizeof(GLfloat);
 	GLuint colorsLen = numVerts * 4 * sizeof(GLfloat);
 
-
-	for(int i = 0; i < 2; i++) {
-		glBindBuffer(GL_ARRAY_BUFFER, vbos[i]);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
 	glBufferData(GL_ARRAY_BUFFER, vertsLen + colorsLen, NULL, GL_STATIC_DRAW);
 
-		glBufferSubData(GL_ARRAY_BUFFER, 0, vertsLen, vertices[i]);
+	glBufferSubData(GL_ARRAY_BUFFER, 0, vertsLen, vertices);
 	glBufferSubData(GL_ARRAY_BUFFER, vertsLen, colorsLen, colors);
 	
-		glBindVertexArray(vaos[i]);
+	glBindVertexArray(vao);
 
 	glEnableVertexAttribArray(posId);
 	glEnableVertexAttribArray(colorId);
 	
 	glVertexAttribPointer(posId, 3, GL_FLOAT, GL_FALSE, 0, 0);
 	glVertexAttribPointer(colorId, 4, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(numVerts * 3 * sizeof(GLfloat)));
-	}
 
-	return vaos;
+	return vao;
 }
 
-void init() {
-	GLuint progId = compileShaders();
-	vaos = setupBuffers(progId);
-	
+void validateProgram(GLuint progId) {
 	glValidateProgram(progId);
 	
 	GLint success;
@@ -143,17 +133,52 @@ void init() {
 	}
 }
 
+void init() {
+	GLfloat vertices[2][9] = {
+		{
+			0.0f, -1.0f, 0.0f,
+			1.0f, -1.0f, 0.0f,
+			0.5f, 1.0f, 0.0f
+		},
+
+		{
+			-1.0f, -1.0f, 0.0f,
+			0.0f, -1.0f, 0.0f,
+			-0.5f, 1.0f, 0.0f
+		}
+	};
+
+	vaos = new GLuint[2];
+	progIds = new GLuint[2];
+
+	GLuint progId1 = compileShaders((char*)"vertex.glsl", (char*)"fragment.glsl");
+	vaos[0] = setupBuffers(vertices[0], progId1);
+	progIds[0] = progId1;
+	validateProgram(progId1);
+	
+	GLuint progId2 = compileShaders((char*)"vertex.glsl", (char*)"yellow.glsl");
+	vaos[1] = setupBuffers(vertices[1], progId2);
+	progIds[1] = progId2;
+	validateProgram(progId2);
+}
+
+void keyboard(unsigned char key, int x, int y) {
+	glutPostRedisplay();
+}
+
 int main(int argc, char** argv) {
 	glutInit(&argc, argv);
-	glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB|GLUT_3_2_CORE_PROFILE);
+	glutInitDisplayMode(GLUT_STENCIL|GLUT_SINGLE|GLUT_RGB|GLUT_3_2_CORE_PROFILE);
 	glutInitWindowSize(800, 600);
-	glutCreateWindow("Hello Triangle");
+	int win = glutCreateWindow("Hello Triangle");
 	glutDisplayFunc(display);
 
 	glewInit();
 	
 	init();
 
+	glutKeyboardFunc(keyboard);
+
 	glutMainLoop();
 
 	return 0;