From: Luke Lau <luke_lau@icloud.com>
Date: Sun, 16 Sep 2018 01:04:20 +0000 (+0100)
Subject: Initial commit
X-Git-Tag: assignment-1~4
X-Git-Url: http://git.lukelau.me/?p=opengl.git;a=commitdiff_plain;h=1dcbad027a4537b550766e9053a4418e8256c81c;ds=sidebyside

Initial commit
---

1dcbad027a4537b550766e9053a4418e8256c81c
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..0505cd2
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,12 @@
+.DS_Store
+*.swp
+CMakeCache.txt
+CMakeFiles
+CMakeScripts
+Testing
+Makefile
+cmake_install.cmake
+install_manifest.txt
+compile_commands.json
+CTestTestfile.cmake
+bin
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..10ab545
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,24 @@
+cmake_minimum_required(VERSION 2.6)
+project(assignment-1)
+set(CMAKE_BINARY_DIR "bin")
+set(EXECUTABLE_OUTPUT_PATH ${CMAKE_BINARY_DIR})
+add_executable(assignment-1 assignment1.cpp)
+
+find_package(OpenGL REQUIRED)
+include_directories(${OPENGL_INCLUDE_DIRS})
+target_link_libraries(assignment-1 ${OPENGL_LIBRARIES})
+
+find_package(GLUT REQUIRED)
+if(NOT GLUT_FOUND)
+	message(ERROR "GLUT not found")
+endif(NOT GLUT_FOUND)
+include_directories(${GLUT_INCLUDE_DIR})
+target_link_libraries(assignment-1 ${GLUT_LIBRARIES})
+
+find_package(GLEW REQUIRED)
+if(NOT GLEW_FOUND)
+	message(ERROR "GLEW not found")
+endif(NOT GLEW_FOUND)
+include_directories(${GLEW_INCLUDE_DIR})
+target_link_libraries(assignment-1 ${GLEW_LIBRARIES})
+
diff --git a/assignment1.cpp b/assignment1.cpp
new file mode 100644
index 0000000..43cd626
--- /dev/null
+++ b/assignment1.cpp
@@ -0,0 +1,153 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <fstream>
+#include <sstream>
+#ifdef __APPLE__
+#include <GL/glew.h>
+#else
+#include <OpenGL/glew.h>
+#endif
+#include <GLUT/glut.h>
+
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+
+using namespace std;
+
+void display() {
+	glClear(GL_COLOR_BUFFER_BIT);
+	glDrawArrays(GL_TRIANGLES, 0, 6);
+	glutSwapBuffers();
+}
+
+void attachShader(GLuint progId, const char* filePath, GLenum type) {
+	GLuint shader = glCreateShader(type);
+
+	if (!shader) {
+		fprintf(stderr, "error creating shader\n");
+		exit(1);
+	}
+
+	ifstream file(filePath);
+	stringstream buffer;
+	buffer << file.rdbuf();
+	const char* contents = buffer.str().c_str();
+
+	glShaderSource(shader, 1, (const GLchar**)&contents, NULL);
+	glCompileShader(shader);
+	GLint success;
+	glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
+	if (!success) {
+		GLchar log[1024];
+		glGetShaderInfoLog(shader, 1024, NULL, log);
+		fprintf(stderr, "error: %s\n", log);
+		exit(1);
+	}
+	glAttachShader(progId, shader);
+}
+
+GLuint compileShaders() {
+	GLuint progId = glCreateProgram();
+
+	attachShader(progId, "vertex.glsl", GL_VERTEX_SHADER);
+	attachShader(progId, "fragment.glsl", GL_FRAGMENT_SHADER);
+
+	glLinkProgram(progId);
+	GLint success = 0;
+	glGetProgramiv(progId, GL_LINK_STATUS, &success);
+	if (!success) {
+		GLchar log[1024];
+		glGetProgramInfoLog(progId, sizeof(log), NULL, log);
+		fprintf(stderr, "error linking: %s\n", log);
+		exit(1);
+	}
+
+	glUseProgram(progId);
+	return progId;
+}
+
+void generateObjectBuffers() {
+	GLfloat vertices[] = {
+		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
+	};
+
+	GLfloat colors[] = {
+		0, 1, 0, 1,
+		1, 0, 0, 1,
+		0, 0, 1, 1,
+		
+		0, 1, 0, 1,
+		1, 0, 0, 1,
+		0, 0, 1, 1			
+	};
+
+	GLuint numVerts = 6;
+
+	GLuint VBO;
+	glGenBuffers(1, &VBO);
+	glBindBuffer(GL_ARRAY_BUFFER, VBO);
+	glBufferData(GL_ARRAY_BUFFER, numVerts * 7 * sizeof(GLfloat), NULL, GL_STATIC_DRAW);
+
+	GLuint vertsLen = numVerts * 3 * sizeof(GLfloat);
+	GLuint colorsLen = numVerts * 4 * sizeof(GLfloat);
+	glBufferSubData(GL_ARRAY_BUFFER, 0, vertsLen, vertices);
+	glBufferSubData(GL_ARRAY_BUFFER, vertsLen, colorsLen, colors);
+}
+
+#define BUFFER_OFFSET(i) ((char *)NULL + (i))
+
+void linkBuffers(GLuint progId) {
+	GLuint numVerts = 6;
+	GLuint posId = glGetAttribLocation(progId, "vPosition");
+	GLuint colorId = glGetAttribLocation(progId, "vColor");
+
+	GLuint vao = 0;
+	glGenVertexArrays(1, &vao);
+	glBindVertexArray(vao);
+
+	glEnableVertexAttribArray(posId);
+	glVertexAttribPointer(posId, 3, GL_FLOAT, GL_FALSE, 0, 0);
+
+	glEnableVertexAttribArray(colorId);
+	glVertexAttribPointer(colorId, 4, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(numVerts * 3 * sizeof(GLfloat)));
+
+}
+
+void init() {
+	GLuint progId = compileShaders();
+	generateObjectBuffers();
+	linkBuffers(progId);
+	
+	glValidateProgram(progId);
+	
+	GLint success;
+	glGetProgramiv(progId, GL_VALIDATE_STATUS, &success);
+	if (!success) {
+		GLchar log[1024];
+		glGetProgramInfoLog(progId, sizeof(log), NULL, log);
+		fprintf(stderr, "error: %s\n", log);
+		exit(1);
+	}
+}
+
+int main(int argc, char** argv) {
+	glutInit(&argc, argv);
+	glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB|GLUT_3_2_CORE_PROFILE);
+	glutInitWindowSize(800, 600);
+	glutCreateWindow("Hello Triangle");
+	glutDisplayFunc(display);
+
+	glewInit();
+	
+	init();
+
+	glutMainLoop();
+
+	return 0;
+}
+
diff --git a/fragment.glsl b/fragment.glsl
new file mode 100644
index 0000000..edc4f63
--- /dev/null
+++ b/fragment.glsl
@@ -0,0 +1,7 @@
+#version 330
+in vec4 color;
+out vec4 FragColor;
+
+void main() {
+	FragColor = color;
+}
diff --git a/vertex.glsl b/vertex.glsl
new file mode 100644
index 0000000..6333f54
--- /dev/null
+++ b/vertex.glsl
@@ -0,0 +1,9 @@
+#version 330
+in vec3 vPosition;
+in vec4 vColor;
+out vec4 color;
+
+void main() {
+	gl_Position = vec4(vPosition, 1.0);
+	color = vColor;
+}