当我在下面的代码中调用 glUniformMatrix4fv 或 glUniform4fv 时,它每次都会引发 GL_INVALID_OPERATION ,我尝试更改传递矩阵数据的方式、传递 id 的计数,我检查了模型 ids 和着色器程序,但无法计算知道它为什么这样做。
这是着色器:
uniform vec4 projection; /* view port / perspective */
uniform vec4 model; /* object */
uniform vec4 view; /*camera */
in vec3 position;
void main() {
gl_Position = projection * view * model * vec4(position, 1.0);
}
这是我的代码:
#include <iostream>
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <glm/glm.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtx/transform.hpp>
#include <fstream>
#include <stdlib.h>
GLuint getShader(const char* shaderName, GLenum shaderType) {
/* Read file */
std::ifstream shaderFile;
shaderFile.open(shaderName, std::ios_base::in);
if(!shaderFile) {
std::cout << shaderName << " not found" << std::endl;
return 0;
}
std::string line;
std::string shaderData;
while(std::getline(shaderFile, line)) {
shaderData += line + "\n";
}
shaderFile.close();
/* Create shader */
GLuint shader = glCreateShader(shaderType);
if(shader == 0) {
std::cout << "Failed to create shader for " << shaderName << std::endl;
return 0;
}
const char *shaderStr = shaderData.c_str();
glShaderSource(shader, 1, &shaderStr, nullptr);
glCompileShader(shader);
/* Check compile status */
GLint status;
glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
if(status != GL_TRUE) {
GLint logLength;
glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &logLength);
GLchar* infoLog = new GLchar[logLength + 1];
glGetShaderInfoLog(shader, logLength, nullptr, infoLog);
std::cout << shaderName << " failed to compile: " << infoLog << std::endl;
return 0;
}
return shader;
}
int end(const char* message) {
glfwTerminate();
if(message != nullptr) {
std::cout << message << std::endl;
system("PAUSE");
}
return 1;
}
int main() {
/* Initial checks */
if (!glfwInit()) {
return end("Failed to startup GLFW");
}
/* Create the window */
GLFWwindow *window = glfwCreateWindow(500, 500, "3D world prototyping", nullptr, nullptr);
if (!window) {
return end("Failed to create window.");
}
glfwMakeContextCurrent(window); //make the window active
/* Startup GLEW */
glewExperimental = GL_TRUE;
if (glewInit() != GLEW_OK) {
return end("Failed to startup GLEW");
}
/* Start OpenGL constants */
glEnable(GL_DEPTH_TEST);
glViewport(0, 0, 500, 500);
/* Support for multiple shaders without the need to switch attributes */
GLuint vertexArray;
glGenVertexArrays(1, &vertexArray);
glBindVertexArray(vertexArray);
/* Create buffers */
GLuint vertexBuffer;
glGenBuffers(1, &vertexBuffer);
/* Shape vectors */
GLfloat verticies[] = { //X, Y, Z
-0.5f, -0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, 0.5f, -0.5f,
0.5f, 0.5f, -0.5f,
-0.5f, 0.5f, -0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, -0.5f, 0.5f,
0.5f, -0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
-0.5f, -0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
-0.5f, 0.5f, -0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, -0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
0.5f, 0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, -0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
-0.5f, -0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, -0.5f, 0.5f,
0.5f, -0.5f, 0.5f,
-0.5f, -0.5f, 0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, 0.5f, -0.5f,
0.5f, 0.5f, -0.5f,
0.5f, 0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
-0.5f, 0.5f, -0.5f,
-1.0f, -1.0f, -0.5f,
1.0f, -1.0f, -0.5f,
1.0f, 1.0f, -0.5f,
1.0f, 1.0f, -0.5f,
-1.0f, 1.0f, -0.5f,
-1.0f, -1.0f, -0.5f
};
glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(verticies), verticies, GL_STATIC_DRAW);
/* Load in the shaders */
GLuint fragmentShader = getShader("fragmentShader.glsl", GL_FRAGMENT_SHADER);
GLuint vertexShader = getShader("vertexShader.glsl", GL_VERTEX_SHADER);
if (fragmentShader == 0 || vertexShader == 0) {
return end("Failed to load shaders");
}
/* Setup the shaders */
/* Create the shader program and use it */
GLuint shaderProgram = glCreateProgram();
if (shaderProgram == 0) {
return end("Failed to create shader program");
}
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glBindFragDataLocation(shaderProgram, 0, "outColor"); //tell opengl about the out color variable
glLinkProgram(shaderProgram);
if(glIsProgram(shaderProgram) != GL_TRUE) {
return end("Failed to create shader program");
}
/* Positioning */
//FOV, Screen ratio, display range short, display range long
glm::mat4 projection = glm::perspective(glm::radians(45.0f), 4.0f / 3.0f, 0.1f, 100.0f);
glm::mat4 view = glm::lookAt(
glm::vec3(4.0f, 3.0f, 3.0f), // Camera
glm::vec3(0.0f, 0.0f, 0.0f), // Where the camera looks up
glm::vec3(0.0f, 1.0f, 0.0f) // Pitch of the head
);
glm::mat4 model = glm::mat4(1.0f);
/* Rendering and logic */
while (!glfwWindowShouldClose(window)) {
/* Shutdown logic */
if (glfwGetKey(window, GLFW_KEY_ESCAPE)) {
break;
}
/* Clear */
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glClearColor(0.2f, 0.2f, 0.2f, 1.0f);
/* Logic */
glUseProgram(shaderProgram);
GLint projectionId = glGetUniformLocation(shaderProgram, "projection");
GLint viewId = glGetUniformLocation(shaderProgram, "view");
GLint modelId = glGetUniformLocation(shaderProgram, "model");
GLenum error = glGetError();
if(error != GL_NO_ERROR) {
std::cout << "Uniform error " << error << ": " << glewGetErrorString(error) << std::endl;
return end("");
}
else if(projectionId == -1) {
return end("Projection ID failed to load");
}
else if(viewId == -1) {
return end("View ID failed to load");
}
else if(modelId == -1) {
return end("Model ID failed to load");
}
glUniformMatrix4fv(viewId, 3, GL_FALSE, glm::value_ptr(view));
error = glGetError();
if(error != GL_NO_ERROR) {
std::cout << "View uniform matrix error " << error << ": " << glewGetErrorString(error) << std::endl;
}
glUniformMatrix4fv(projectionId, 3, GL_FALSE, glm::value_ptr(projection));
error = glGetError();
if(error != GL_NO_ERROR) {
std::cout << "Projection matrix error " << error << ": " << glewGetErrorString(error) << std::endl;
}
glUniformMatrix4fv(modelId, 3, GL_FALSE, glm::value_ptr(model));
error = glGetError();
if(error != GL_NO_ERROR) {
std::cout << "Model uniform matrix error " << error << ": " << glewGetErrorString(error) << std::endl;
}
/* Tell opengl about all the attributes */
GLint positionAttribute = glGetAttribLocation(shaderProgram, "position");
if(positionAttribute == -1) {
std::cout << "Error: position attribute failed to load" << std::endl;
end("");
}
error = glGetError();
if(error != GL_NO_ERROR) {
std::cout << "Position attribute error " << error << ": " << glewGetErrorString(error) << std::endl;
}
glEnableVertexAttribArray(positionAttribute);
error = glGetError();
if(error != GL_NO_ERROR) {
std::cout << "Vertex enable error " << error << ": " << glewGetErrorString(error) << std::endl;
}
glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
error = glGetError();
if(error != GL_NO_ERROR) {
std::cout << "Buffer bind error " << error << ": " << glewGetErrorString(error) << std::endl;
}
glVertexAttribPointer(positionAttribute, 3, GL_FLOAT, GL_FALSE, 0, 0); //because not just XYZ need to tell opengl the size of the stride
error = glGetError();
if(error != GL_NO_ERROR) {
std::cout << "Vertex attrib pointer error " << error << ": " << glewGetErrorString(error) << std::endl;
}
/* Draw */
glDrawArrays(GL_TRIANGLES, 0, 36);
error = glGetError();
if(error != GL_NO_ERROR) {
std::cout << "gl draw arrays " << error << ": " << glewGetErrorString(error) << std::endl;
}
glDisableVertexAttribArray(positionAttribute);
error = glGetError();
if(error != GL_NO_ERROR) {
std::cout << "gl disable attrib error " << error << ": " << glewGetErrorString(error) << std::endl;
}
glfwSwapBuffers(window);
glfwPollEvents();
error = glGetError();
if(error != GL_NO_ERROR) {
std::cout << "Error " << error << ": " << glewGetErrorString(error) << std::endl;
}
}
glfwDestroyWindow(window);
glDeleteProgram(shaderProgram);
glDeleteShader(fragmentShader);
glDeleteShader(vertexShader);
glDeleteBuffers(1, &vertexBuffer);
glDeleteVertexArrays(1, &vertexArray);
return end(nullptr);
}
对于有问题的特定制服,您使用了错误的 API 调用来设置它们。
这些是向量,而不是矩阵。您可以使用
glUniform4fv (...)
而不是 glUniformMatrix4fv (...)
。后一个函数假设您正在设置 1 个或多个 4x4 矩阵制服(您传递的参数告诉它 projection
应该是 3 mat4
的数组)。
我相信在您的情况下,适当的函数调用将如下所示:
glUniform4fv (modelId, 1, glm::value_ptr(model)); // Fill 1 4D vector, not an array of vectors
当您调用的 setter 函数与您尝试设置的制服的数据类型不匹配时,设置制服将导致
GL_INVALID_OPERATION
错误。
自从您将制服声明为向量以来:
uniform vec4 projection; /* view port / perspective */
uniform vec4 model; /* object */
uniform vec4 view; /*camera */
您不能使用 matrix 设置器。您应该将 Uniformst 更改为
mat4
才能使您的代码正常工作。
作为一个小旁注:如果您尝试设置位置为 -1 的制服(意味着制服不存在或已被优化),它不会 生成错误。这是明确允许的,可能是为了允许通用框架,其中着色器可能只使用制服的子集。