Hello,
I am trying to draw a simple cube for a homework assignment for a class but for some reason it isn't showing up.
I am using uniform blocks and modern OpenGL. I am sure I am not doing something correctly.
My complete code is below. The below example depends on GLEW + GLFW + GLM.
Any ideas?
Thank you:
#include <iostream>
#include <string>
#include <sstream>
#include <vector>
#include <algorithm>
#ifndef OPENGL_INCLUDES_
#define OPENGL_INCLUDES_
#include "GL\glew.h"
#ifndef GLFW_INCLUDES_
#define GLFW_INCLUDES_
#if defined(_WIN32)
#include <Windows.h>
#define GLFW_EXPOSE_NATIVE_WIN32
#define GLFW_EXPOSE_NATIVE_WGL
#elif defined(__linux__)
#include <X11/X.h>
#include <X11/extensions/Xrandr.h>
#define GLFW_EXPOSE_NATIVE_X11
#define GLFW_EXPOSE_NATIVE_GLX
#endif
#include "GLFW\glfw3.h"
#include "GLFW\glfw3native.h"
#endif
#endif
#ifndef GLM_INCLUDES_
#define GLM_INCLUDES_
#include <glm/glm.hpp>
#include <glm/gtx/rotate_vector.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtx/transform.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <glm/gtc/quaternion.hpp>
#include <glm/gtx/quaternion.hpp>
#endif
GLFWwindow* MainWindow;
#ifdef _WIN32
HWND MainWindowWin32Handle;
#endif
GLint WindowWidth = 1024;
GLint WindowHeight = 768;
GLulong SizeDivizor = 1;
GLboolean RiftAvailable = false;
GLboolean UseApplicationWindowFrame = false;
GLuint MainOpenGLShaderProgramID;
GLuint MatricesUniformBlockID;
GLuint MatricesUniformBufferID;
GLuint LightsUniformBlockID;
GLuint LightsUniformBufferID;
GLuint MaterialsUniformBlockID;
GLuint MaterialsUniformBufferID;
glm::mat4 ViewMatrix;
glm::mat4 ViewModelMatrix;
glm::mat4 ProjectionMatrix;
glm::mat4 MVPMatrix;
glm::mat3 NormalMatrix;
class StandardCube;
std::vector<StandardCube> Cubes;
class StandardCube {
private:
GLfloat* Vertices;
GLfloat* Normals;
GLuint* Indices;
GLuint VAO;
glm::mat4 ModelMatrix;
public:
void LoadIntoOpenGL() {
Vertices = new GLfloat[72]
{
1.0f, 1.0f, 1.0f,
-1.0f, 1.0f, 1.0f,
-1.0f, -1.0f, 1.0f,
1.0f, -1.0f, 1.0f,
-1.0f, -1.0f, -1.0f,
-1.0f, 1.0f, -1.0f,
1.0f, 1.0f, -1.0f,
1.0f, -1.0f, -1.0f,
1.0f, 1.0f, 1.0f,
1.0f, 1.0f, -1.0f,
-1.0f, 1.0f, -1.0f,
-1.0f, 1.0f, 1.0f,
-1.0f, -1.0f, -1.0f,
1.0f, -1.0f, -1.0f,
1.0f, -1.0f, 1.0f,
-1.0f, -1.0f, 1.0f,
1.0f, 1.0f, 1.0f,
1.0f, -1.0f, 1.0f,
1.0f, -1.0f, -1.0f,
1.0f, 1.0f, -1.0f,
-1.0f, -1.0f, -1.0f,
-1.0f, -1.0f, 1.0f,
-1.0f, 1.0f, 1.0f,
-1.0f, 1.0f, -1.0f
};
Normals = new GLfloat[72] {
0.0f, 0.0f, 1.0f,
0.0f, 0.0f, 1.0f,
0.0f, 0.0f, 1.0f,
0.0f, 0.0f, 1.0f,
0.0f, 0.0f, -1.0f,
0.0f, 0.0f, -1.0f,
0.0f, 0.0f, -1.0f,
0.0f, 0.0f, -1.0f,
0.0f, 1.0f, 0.0f,
0.0f, 1.0f, 0.0f,
0.0f, 1.0f, 0.0f,
0.0f, 1.0f, 0.0f,
0.0f, -1.0f, 0.0f,
0.0f, -1.0f, 0.0f,
0.0f, -1.0f, 0.0f,
0.0f, -1.0f, 0.0f,
1.0f, 0.0f, 0.0f,
1.0f, 0.0f, 0.0f,
1.0f, 0.0f, 0.0f,
1.0f, 0.0f, 0.0f,
-1.0f, 0.0f, 0.0f,
-1.0f, 0.0f, 0.0f,
-1.0f, 0.0f, 0.0f,
-1.0f, 0.0f, 0.0f
};
Indices = new GLuint[36] {0, 1, 2, 2, 3, 0,
4, 5, 6, 6, 7, 4,
8, 9, 10, 10, 11, 8,
12, 13, 14, 14, 15, 12,
16, 17, 18, 18, 19, 16,
20, 21, 22, 22, 23, 20
};
glGenVertexArrays(1, &VAO);
glBindVertexArray(VAO);
GLuint MeshBufferID;
glGenBuffers(1, &MeshBufferID);
glBindBuffer(GL_ARRAY_BUFFER, MeshBufferID);
GLuint TotalBufferData = (sizeof(GLfloat) * 72) + (sizeof(GLfloat) * 72);
glBufferData(GL_ARRAY_BUFFER, TotalBufferData, NULL, GL_STATIC_DRAW);
glBufferSubData(GL_ARRAY_BUFFER, NULL, sizeof(GLfloat) * 72, Vertices);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(0);
glBufferSubData(GL_ARRAY_BUFFER, sizeof(GLfloat) * 72, sizeof(GLfloat) * 72, Normals);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, (GLvoid*)(sizeof(GLfloat) * 72));
glEnableVertexAttribArray(1);
GLuint IndexBufferID;
glGenBuffers(1, &IndexBufferID);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, IndexBufferID);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(GLint) * 36, Indices, GL_STATIC_DRAW);
glBindVertexArray(NULL);
ModelMatrix = glm::mat4(1.0f);
}
void DrawMe() {
MVPMatrix = ProjectionMatrix * ViewMatrix * ModelMatrix;
ViewModelMatrix = ViewMatrix * ModelMatrix;
NormalMatrix = glm::transpose(glm::inverse(glm::mat3(MVPMatrix)));
glBindBuffer(GL_UNIFORM_BUFFER, MatricesUniformBufferID);
glBufferSubData(GL_UNIFORM_BUFFER, NULL, sizeof(glm::mat4), glm::value_ptr(MVPMatrix));
glBufferSubData(GL_UNIFORM_BUFFER, sizeof(glm::mat4), sizeof(glm::mat4), glm::value_ptr(ViewModelMatrix));
glBufferSubData(GL_UNIFORM_BUFFER, sizeof(glm::mat4) + sizeof(glm::mat4), sizeof(glm::mat3), glm::value_ptr(NormalMatrix));
glBindBuffer(GL_UNIFORM_BUFFER, NULL);
glBindVertexArray(VAO);
glDrawElementsInstanced(GL_TRIANGLES, 36, GL_UNSIGNED_INT, NULL, 1);
glBindVertexArray(NULL);
}
};
static void GLFWKeyCallback(GLFWwindow* p_Window, GLint p_Key, GLint p_Scancode, GLint p_Action, GLint p_Mods) {
if (p_Key == GLFW_KEY_ESCAPE && p_Action == GLFW_PRESS) {
glfwSetWindowShouldClose(p_Window, GL_TRUE);
}
if (p_Key == GLFW_KEY_O && p_Action == GLFW_PRESS) {
glClearColor(0.2f, 0.1f, 0.3f, 1.0f);
}
if (p_Key == GLFW_KEY_I && p_Action == GLFW_PRESS) {
glClearColor(1.0f, 0.5f, 0.5f, 1.0f);
}
}
static void GLFWWindowResizeCallBack(GLFWwindow* p_Window, GLint width, GLint height) {
//CurrentGLFWApplication->WindowResizeCallBack(p_Window, width, height);
}
static void GLFWMouseMovementCallBack(GLFWwindow* p_Window, GLdouble MouseX, GLdouble MouseY) {
//CurrentGLFWApplication->MouseMovementCallBack(p_Window, MouseX, MouseY);
}
static void GLFWFramebufferSizeCallback(GLFWwindow* window, GLint width, GLint height)
{
glViewport(0, 0, width, height);
}
int initializeGLFWGLEW() {
MainWindow = NULL;
if (!glfwInit())
{
fprintf(stderr, "GLFW failed to initialize.");
glfwTerminate();
return EXIT_FAILURE;
}
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_ANY_PROFILE);
if (UseApplicationWindowFrame) {
MainWindow = glfwCreateWindow(WindowWidth, WindowHeight, "Basic Oculus Rift Example", NULL, NULL);
}
else {
if (!RiftAvailable) {
MainWindow = glfwCreateWindow(WindowWidth, WindowHeight, "Basic Oculus Rift Example", NULL, NULL);
}
else {
GLint MonitorCount;
GLFWmonitor** GLFW_Monitors = glfwGetMonitors(&MonitorCount);
GLFWmonitor* MonitorToUse;
switch (MonitorCount)
{
case 0:
printf("No monitors found, exiting.\n");
return EXIT_FAILURE;
break;
case 1:
printf("Two monitors expected, found only one, using primary...\n");
MonitorToUse = glfwGetPrimaryMonitor();
break;
case 2:
printf("Two monitors found, using second monitor\n");
MonitorToUse = GLFW_Monitors[1];
break;
default:
printf("More than two monitors found, using second monitor\n");
MonitorToUse = GLFW_Monitors[1];
}
MainWindow = glfwCreateWindow(WindowWidth, WindowHeight, "Basic Oculus Rift Example", MonitorToUse, NULL);
}
}
if (!MainWindow)
{
fprintf(stderr, "Could not determine OpenGL version; exiting.");
glfwTerminate();
return EXIT_FAILURE;
}
glfwMakeContextCurrent(MainWindow);
glewExperimental = GL_TRUE;
GLenum err = glewInit();
if (GLEW_OK != err)
{
/* Problem: glewInit failed, something is seriously wrong. */
fprintf(stderr, "Error: %s\n", glewGetErrorString(err));
return EXIT_FAILURE;
}
glfwSetInputMode(MainWindow, GLFW_STICKY_KEYS, GL_TRUE);
glfwSetKeyCallback(MainWindow, GLFWKeyCallback);
glfwSetWindowSizeCallback(MainWindow, GLFWWindowResizeCallBack);
glfwSetCursorPosCallback(MainWindow, GLFWMouseMovementCallBack);
glfwSetFramebufferSizeCallback(MainWindow, GLFWFramebufferSizeCallback);
glfwSwapBuffers(MainWindow);
glfwPollEvents();
return EXIT_SUCCESS;
}
int prepareOpenGL() {
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LESS);
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
glEnable(GL_TEXTURE_2D);
glEnable(GL_BLEND);
glEnable(GL_CULL_FACE);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_MULTISAMPLE);
return EXIT_SUCCESS;
}
int loadShaders() {
// Create the shaders
GLuint VertexShaderID = glCreateShader(GL_VERTEX_SHADER);
GLuint FragmentShaderID = glCreateShader(GL_FRAGMENT_SHADER);
// Compile Vertex Shader
printf("Compiling Vertext Shader.\n\n");
char const * VertexSource = "#version 330 \n\n\
layout(std140) uniform Matrices{\n\
mat4 m_pvm;\n\
mat4 m_viewModel;\n\
mat3 m_normal;\n\
};\n\
layout(std140) uniform Lights{\n\
vec3 l_dir; \n\
};\n\
in vec4 position;\n\
in vec3 normal;\n\
\n\
\n\
out Data{\n\
vec3 normal;\n\
vec4 eye;\n\
} DataOut;\n\
\n\
void main() {\n\
\n\
DataOut.normal = normalize(m_normal * normal);\n\
DataOut.eye = -(m_viewModel * position);\n\
\n\
gl_Position = m_pvm * position;\n\
}\n\
\n";
glShaderSource(VertexShaderID, 1, &VertexSource, NULL);
glCompileShader(VertexShaderID);
// Check Vertex Shader
GLint Result = GL_FALSE;
int InfoLogLength;
glGetShaderiv(VertexShaderID, GL_COMPILE_STATUS, &Result);
glGetShaderiv(VertexShaderID, GL_INFO_LOG_LENGTH, &InfoLogLength);
if (InfoLogLength > 0){
std::vector<char> VertexShaderErrorMessage(InfoLogLength + 1);
glGetShaderInfoLog(VertexShaderID, InfoLogLength, NULL, &VertexShaderErrorMessage[0]);
std::string ErrorMessage = std::string(&VertexShaderErrorMessage[0]);
printf("%s\n", &VertexShaderErrorMessage[0]);
}
printf("Compiling Fragment Shader.\n\n");
char const * FragmentSource = "#version 330\n\
layout(std140) uniform Materials{\n\
vec4 diffuse;\n\
vec4 ambient;\n\
vec4 specular;\n\
vec4 emissive;\n\
float shininess;\n\
int texCount;\n\
};\
\n\
layout(std140) uniform Lights{\n\
vec3 l_dir; \n\
};\
\n\
in Data{\n\
vec3 normal;\n\
vec4 eye;\n\
} DataIn;\n\
\n\
out vec4 colorOut;\
\n\
void main() {\n\
\n\
vec4 spec = vec4(0.0);\n\
\n\
vec3 n = normalize(DataIn.normal);\n\
vec3 e = normalize(vec3(DataIn.eye));\n\
\n\
float intensity = max(dot(n, l_dir), 0.0);\n\
\n\
if (intensity > 0.0) {\n\
vec3 h = normalize(l_dir + e);\n\
\n\
float intSpec = max(dot(h, n), 0.0);\n\
spec = specular * pow(intSpec, shininess);\n\
}\n\
\n\
colorOut = max(intensity * diffuse + spec, ambient);\n\
}";
glShaderSource(FragmentShaderID, 1, &FragmentSource, NULL);
glCompileShader(FragmentShaderID);
// Check Fragment Shader
glGetShaderiv(FragmentShaderID, GL_COMPILE_STATUS, &Result);
glGetShaderiv(FragmentShaderID, GL_INFO_LOG_LENGTH, &InfoLogLength);
if (InfoLogLength > 0){
std::vector<char> FragmentShaderErrorMessage(InfoLogLength + 1);
glGetShaderInfoLog(FragmentShaderID, InfoLogLength, NULL, &FragmentShaderErrorMessage[0]);
std::string ErrorMessage = std::string(&FragmentShaderErrorMessage[0]);
printf("%s\n", &FragmentShaderErrorMessage[0]);
}
// Link the program
printf("Linking shader program.\n\n");
GLuint ProgramID = glCreateProgram();
glAttachShader(ProgramID, VertexShaderID);
glAttachShader(ProgramID, FragmentShaderID);
glLinkProgram(ProgramID);
// Check the program
glGetProgramiv(ProgramID, GL_LINK_STATUS, &Result);
glGetProgramiv(ProgramID, GL_INFO_LOG_LENGTH, &InfoLogLength);
if (InfoLogLength > 0){
std::vector<char> ProgramErrorMessage(InfoLogLength + 1);
glGetProgramInfoLog(ProgramID, InfoLogLength, NULL, &ProgramErrorMessage[0]);
std::string ErrorMessage = std::string(&ProgramErrorMessage[0]);
printf("%s\n", &ProgramErrorMessage[0]);
}
glDeleteShader(VertexShaderID);
glDeleteShader(FragmentShaderID);
MainOpenGLShaderProgramID = ProgramID;
return EXIT_SUCCESS;
}
int prepareShaderUniforms() {
glUseProgram(MainOpenGLShaderProgramID);
MatricesUniformBlockID = glGetUniformBlockIndex(MainOpenGLShaderProgramID, "Matrices");
glUniformBlockBinding(MainOpenGLShaderProgramID, MatricesUniformBlockID, 1);
glGenBuffers(1, &MatricesUniformBufferID);
glBindBuffer(GL_UNIFORM_BUFFER, MatricesUniformBufferID);
glBindBufferBase(GL_UNIFORM_BUFFER, 0, MatricesUniformBufferID);
GLsizeiptr TotalBufferSize = sizeof(glm::mat4) + sizeof(glm::mat4);
TotalBufferSize += sizeof(glm::mat3);
glBufferData(GL_ARRAY_BUFFER, TotalBufferSize, NULL, GL_DYNAMIC_DRAW);
glBindBuffer(GL_UNIFORM_BUFFER, NULL);
LightsUniformBlockID = glGetUniformBlockIndex(MainOpenGLShaderProgramID, "Lights");
glUniformBlockBinding(MainOpenGLShaderProgramID, LightsUniformBlockID, 2);
glGenBuffers(1, &LightsUniformBufferID);
glBindBuffer(GL_UNIFORM_BUFFER, LightsUniformBufferID);
glBindBufferBase(GL_UNIFORM_BUFFER, 0, LightsUniformBufferID);
GLfloat LightDirection[3] = { 1.0f, 1.0f, 0.0f };
glBufferData(GL_UNIFORM_BUFFER, sizeof(LightDirection), &LightDirection, GL_DYNAMIC_DRAW);
glBindBuffer(GL_UNIFORM_BUFFER, NULL);
MaterialsUniformBlockID = glGetUniformBlockIndex(MainOpenGLShaderProgramID, "Materials");
glUniformBlockBinding(MainOpenGLShaderProgramID, MaterialsUniformBlockID, 3);
glGenBuffers(1, &MaterialsUniformBufferID);
glBindBuffer(GL_UNIFORM_BUFFER, MaterialsUniformBufferID);
glBindBufferBase(GL_UNIFORM_BUFFER, 0, MaterialsUniformBufferID);
GLfloat Material[18];
//Diffuse
Material[0] = 0.5f;
Material[1] = 0.0f;
Material[2] = 0.0f;
Material[3] = 1.0f;
//Ambient
Material[4] = 0.2f;
Material[5] = 0.2f;
Material[6] = 0.2f;
Material[7] = 1.0f;
//Specular
Material[8] = 0.0f;
Material[9] = 0.0f;
Material[10] = 0.0f;
Material[11] = 1.0f;
//Emissive
Material[12] = 0.0f;
Material[13] = 0.0f;
Material[14] = 0.0f;
Material[15] = 1.0f;
//Shininess
Material[16] = 2.0f;
//Texture Count
Material[17] = 0.0f;
glBufferData(GL_UNIFORM_BUFFER, sizeof(Material), &Material, GL_DYNAMIC_DRAW);
glBindBuffer(GL_UNIFORM_BUFFER, NULL);
return EXIT_SUCCESS;
}
int loadCubes() {
StandardCube NewCube;
NewCube.LoadIntoOpenGL();
Cubes.push_back(NewCube);
return EXIT_SUCCESS;
}
int prepareMatricies() {
GLfloat AspectRatio = (GLfloat)(WindowWidth) / (GLfloat)(WindowHeight);
ProjectionMatrix = glm::perspective(45.0f, AspectRatio, 1.0f, 1000.0f);
ViewMatrix = glm::lookAt(
glm::vec3(4.0f, 3.0f, 3.0f), // camera is at (4,3,3), in world space - Where the camera is inside world.
glm::vec3(0.0f, 0.0f, 0.0f), // and looks at the origin - What point the camera is looking at inside world.
glm::vec3(0.0f, 1.0f, 0.0f) // head is up(set to 0,1,0) - the direction of up for camera.
);
glViewport(0, 0, WindowWidth, WindowHeight);
return EXIT_SUCCESS;
}
int main(int argc, char** argv) {
if (initializeGLFWGLEW() == EXIT_FAILURE) {
exit(EXIT_FAILURE);
}
if (prepareOpenGL() == EXIT_FAILURE) {
exit(EXIT_FAILURE);
}
if (loadShaders() == EXIT_FAILURE) {
exit(EXIT_FAILURE);
}
if (prepareShaderUniforms() == EXIT_FAILURE) {
exit(EXIT_FAILURE);
}
if (loadCubes() == EXIT_FAILURE) {
exit(EXIT_FAILURE);
}
if (prepareMatricies() == EXIT_FAILURE) {
exit(EXIT_FAILURE);
}
while (!glfwWindowShouldClose(MainWindow))
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
for (auto & C : Cubes) {
C.DrawMe();
}
glfwSwapBuffers(MainWindow);
glfwPollEvents();
}
exit(EXIT_SUCCESS);
}
