为什么这些 GLSL 着色器不起作用？

Why don't these GLSL shaders work?

本文关键字：不起作用 GLSL 为什么      更新时间：2023-10-16

我正在尝试使用着色器覆盖颜色，将螺旋渲染为全红色。出于某种原因，他们编译并链接，但什么也不做。

参见以下代码

碎片hader.glsl

#version 430
out vec4 outColor; 
in vec4 color; 
void main(){
    outColor = color;
}

vertexshader.glsl

#version 430
in layout(location=0) vec2 position;
out vec4 color;
void main(){
    gl_Position = vec4(position, 0.0, 1.0); 
    color = vec4(1.0, 0.0f, 0.0f, 1.0f);
}

Window.cpp

#include <GLglew.h>
#include <glmglm.hpp>
#include <glmgtcmatrix_transform.hpp>
#include "MeGLWindow.h"
#include <iostream>
#include <fstream>
#define Pi 3.14159265358979
#define E 2.718281828F
#define SCREEN_WIDTH 800
#define SCREEN_HEIGHT 600
#define MAX_SPIRAL 25000
std::string readFile(const char* relPath);
void installShaders();
bool checkShaderStatus(GLuint shaderID);
bool checkProgramStatus(GLuint programID);
GLuint programID;
void MeGLWindow::initializeGL() {
    glewInit();
    glEnable(GL_DEPTH_TEST);
    installShaders();
    const int verts_num = MAX_SPIRAL * 2;
    GLfloat verts[50000];
    GLuint myBufferID;
    float a = 0.06f;
    float b = 0.06f;    
    float cx = 0.0;
    float cy = 0.0;
    int z = 0;
    for (int i = 0; i < MAX_SPIRAL; i++) {
        float ang = (Pi / 720) * i;
        float factor = pow(E, b * ang);
        float x = cx + (a * (cos(ang)) * factor);
        float y = cy - (a * (sin(ang)) * factor);
        verts[2 * i] = x;
        verts[(2 * i) + 1] = y;
    }
    glGenBuffers(1, &myBufferID);
    glBindBuffer(GL_ARRAY_BUFFER, myBufferID);
    glBufferData(GL_ARRAY_BUFFER, sizeof(verts), verts, GL_STATIC_DRAW);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, 0); 
}
void MeGLWindow::paintGL() {
    glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
    glViewport(0, 0, width(), height());
    glDrawArrays(GL_POINTS, 0, 2*25000);
}
void installShaders() {
    GLuint vertexShaderID = glCreateShader(GL_VERTEX_SHADER);
    GLuint fragmentShaderID = glCreateShader(GL_FRAGMENT_SHADER);
    const char* adapter[1];
    std::string file = readFile("vertexshader.glsl"); 
    const char* vertexFile = file.c_str(); 
    adapter[0] = vertexFile;
    glShaderSource(vertexShaderID, 1, adapter, 0);
    file = readFile("fragmentshader.glsl");
    const char* fragmentFile = file.c_str();
    adapter[0] = fragmentFile;
    glShaderSource(fragmentShaderID, 1, adapter, 0);
    glCompileShader(vertexShaderID);
    glCompileShader(fragmentShaderID);
    if (!checkShaderStatus(vertexShaderID) ||                 !checkShaderStatus(fragmentShaderID)) {
        return; 
    }
    programID = glCreateProgram();
    glAttachShader(programID, vertexShaderID);
    glAttachShader(programID, fragmentShaderID);
    glLinkProgram(programID);
    if (!checkProgramStatus(programID)) {    
        return; 
    }

    glUseProgram(programID);
}

main.cpp

#include <Qtqapplication.h>
#include "MeGLWindow.h"
int main(int argc, char* argv[]) {
    QApplication app(argc, argv);
    MeGLWindow meWindow; 
    meWindow.show(); 
    return app.exec();
}

根据链接的着色器，缓和曲线中的顶点应为红色！我做错了什么？请帮忙！

  • 着色器程序上没有错误检查。或者更确切地说，您检查错误，但不向应用程序发出程序创建以任何方式失败的信号。

  • 您没有提供checkProgramStatus的源，但如果您检查GL_LINK_STATUS，则在链接问题之前执行。

  • 目前尚不清楚您是如何从提供的代码中初始化OpenGL的，但您没有设置核心配置文件所需的VAO。

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