我正在尝试为一个班级的家庭作业画一个简单的立方体，但由于某种原因它没有出现。
我正在使用统一块和现代OpenGL。我确信我没有做正确的事。
我的完整代码如下。以下示例取决于GLEW + GLFW + GLM。
我发现有趣的是，对于我的光和材质均匀块，我得到了索引但是我的MVP矩阵的统一块我没有得到索引。
有什么想法吗？
这是C ++代码：
#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 MatrixInformation {\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);
LightsUniformBlockID = glGetUniformBlockIndex(MainOpenGLShaderProgramID, "Lights");
glUniformBlockBinding(MainOpenGLShaderProgramID, LightsUniformBlockID, 2);
glGenBuffers(1, &LightsUniformBufferID);
glBindBuffer(GL_UNIFORM_BUFFER, LightsUniformBufferID);
glBindBufferBase(GL_UNIFORM_BUFFER, 2, 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);
MatricesUniformBlockID = glGetUniformBlockIndex(MainOpenGLShaderProgramID, "MatrixInformation");
glUniformBlockBinding(MainOpenGLShaderProgramID, MatricesUniformBlockID, 1);
glGenBuffers(1, &MatricesUniformBufferID);
glBindBuffer(GL_UNIFORM_BUFFER, MatricesUniformBufferID);
glBindBufferBase(GL_UNIFORM_BUFFER, 1, 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);
MaterialsUniformBlockID = glGetUniformBlockIndex(MainOpenGLShaderProgramID, "Materials");
glUniformBlockBinding(MainOpenGLShaderProgramID, MaterialsUniformBlockID, 3);
glGenBuffers(1, &MaterialsUniformBufferID);
glBindBuffer(GL_UNIFORM_BUFFER, MaterialsUniformBufferID);
glBindBufferBase(GL_UNIFORM_BUFFER, 3, 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);
}
这是我的顶点着色器：
#version 330
layout(std140) uniform MatrixInformation {
mat4 m_pvm;
mat4 m_viewModel;
mat3 m_normal;
};
layout(std140) uniform Lights {
vec3 l_dir;
};
in vec4 position;
in vec3 normal;
out Data{
vec3 normal;
vec4 eye;
} DataOut;
void main() {
DataOut.normal = normalize(m_normal * normal);
DataOut.eye = -(m_viewModel * position);
gl_Position = m_pvm * position;
}
这是我的片段着色器：
#version 330
layout(std140) uniform Materials {
vec4 diffuse;
vec4 ambient;
vec4 specular;
vec4 emissive;
float shininess;
int texCount;
};
layout(std140) uniform Lights {
vec3 l_dir;
};
in Data{
vec3 normal;
vec4 eye;
} DataIn;
out vec4 colorOut;
void main() {
vec4 spec = vec4(0.0);
vec3 n = normalize(DataIn.normal);
vec3 e = normalize(vec3(DataIn.eye));
float intensity = max(dot(n, l_dir), 0.0);
if (intensity > 0.0) {
vec3 h = normalize(l_dir + e);
float intSpec = max(dot(h, n), 0.0);
spec = specular * pow(intSpec, shininess);
}
colorOut = max(intensity * diffuse + spec, ambient);
}
答案 0 :(得分：1)
所以问题在于这一部分：
//Binding uniform buffer
glBindBuffer(GL_UNIFORM_BUFFER, MatricesUniformBufferID);
glBindBufferBase(GL_UNIFORM_BUFFER, 1, MatricesUniformBufferID);
GLsizeiptr TotalBufferSize = sizeof(glm::mat4) + sizeof(glm::mat4);
TotalBufferSize += sizeof(glm::mat3);
//uploading to the unbound array buffer
glBufferData(GL_ARRAY_BUFFER, TotalBufferSize, NULL, GL_DYNAMIC_DRAW);
glBindBuffer(GL_UNIFORM_BUFFER, NULL);
所以你需要改变
glBufferData(GL_ARRAY_BUFFER, TotalBufferSize, NULL, GL_DYNAMIC_DRAW);
到
glBufferData(GL_UNIFORM_BUFFER, TotalBufferSize, NULL, GL_DYNAMIC_DRAW);
另外上传NULL对我的OpenGL驱动程序不起作用（尽管它应该），所以我不得不
std::array<unsigned char,sizeof(glm::mat4)*2+sizeof(glm::mat3)> buff;
glBufferData(GL_UNIFORM_BUFFER, TotalBufferSize, buff.data(), GL_DYNAMIC_DRAW);
至于你如何发现这一点：老派的方法是用glGetError调用来调试你的代码只能在调试模式下运行。更现代的方法是在回调上创建调试上下文和打印中断以找出错误的位置（然后你可以在该区域进行glGetError调用以获得确切的函数调用（如果你不知道它）到那时，由于现代OpenGL驱动程序是线程化的，并且回调可能会在稍后触发一个或两个函数调用。