OpenGL的“黑屏”的渲染利用Shader

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“顶点着色”三角形时，我很新的OpenGL和一直跟着非常简单的教程在那里我应该创建一个顶点着色三角形（the tutorial in question）。OpenGL的“黑屏”的渲染利用Shader

虽然，我的成绩刚刚出来一个黑色的屏幕。我试着完全复制他的代码，但它仍然不起作用，这导致我相信教程已过时。

我试图消除在着色器“的#Version 130”，但什么也没做。我也调试了渲染函数，它确实被调用。我不知道什么可能是错的。

这是我的代码：

的main.cpp

#ifdef _WIN32 
#define _CRT_SECURE_NO_DEPRECATE 
#endif 

#include <GL\glew.h> 
#include <GL\freeglut.h> 
#include <stdio.h> 

#define BUFFER_OFFSET(i) ((char *)NULL + (i)) 
GLuint shaderProgramID; 
GLuint vao = 0; 
GLuint vbo; 
GLuint positionID, colorID; 

#pragma region SHADER_FUNCTIONS 
static char* readFile(const char* filename) { 
    //Open the file 
    FILE* fp = fopen(filename, "r"); 
    //Move to the end of file 
    fseek(fp, 0, SEEK_END); 
    long file_length = ftell(fp); 
    fseek(fp, 0, SEEK_SET); 
    char* contents = new char[file_length + 1]; 
    //zero out memory 
    for (int i = 0; i < file_length + 1; i++) { 
     contents[i] = 0; 
    } 
    //Read file 
    fread(contents, 1, file_length, fp); 
    //Denote end 
    contents[file_length + 1] = '\0'; 
    fclose(fp); 
    return contents; 
} 

GLuint makeVertexShader(const char* shaderSource) { 
    GLuint vertexShaderID = glCreateShader(GL_VERTEX_SHADER); 
    glShaderSource(vertexShaderID, 1, (const GLchar**)&shaderSource, NULL); 
    glCompileShader(vertexShaderID); 
    return vertexShaderID; 
} 

GLuint makeFragmentShader(const char* shaderSource) { 
    GLuint fragmentShaderID = glCreateShader(GL_FRAGMENT_SHADER); 
    glShaderSource(fragmentShaderID, 1, (const GLchar**)&shaderSource, NULL); 
    glCompileShader(fragmentShaderID); 
    return fragmentShaderID; 
} 

GLuint makeShaderProgram(GLuint vertexShaderID, GLuint fragmentShaderID) { 
    GLuint shaderID = glCreateProgram(); 
    glAttachShader(shaderID, vertexShaderID); 
    glAttachShader(shaderID, fragmentShaderID); 
    glLinkProgram(shaderID); 
    return shaderID; 
} 
#pragma endregion 

void changeViewport(int w, int h) { 
    glViewport(0, 0, w, h); 
} 

void render() { 
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 
    glDrawArrays(GL_TRIANGLES, 0, 3); 
    glutSwapBuffers(); 
    printf("Debug"); 
} 

int main(int argc, char** argv) { 
    //Init GLUT 
    glutInit(&argc, argv); 

    //Set up some memory buffers for our display 
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH); 
    //Set up window size 
    glutInitWindowSize(800, 600); 
    //Create window 
    glutCreateWindow("Project 1"); 
    //Bind the two functions to respond when necessary 
    glutReshapeFunc(changeViewport); 
    glutDisplayFunc(render); 

    //Initialize OpenGL driver 
    GLenum err = glewInit(); 
    if (GLEW_OK != err) { 
     fprintf(stderr, "GLEW error"); 
     return 1; 
    } 

    //Vertices and colors of trangle 
    GLfloat vertices[] = { 
     -0.5f, -0.5f, 0.0f, 
     0.5f, -0.5f, 0.0f, 
     0.0f,-0.5f, 0.0f 
    }; 
    GLfloat colors[] = { 
     1.0f, 0.0f, 0.0f, 1.0f, 
     0.0f, 1.0f, 0.0f, 1.0f, 
     0.0f, 0.0f, 1.0f, 1.0f 
    }; 

    #pragma region MAKE_SHADER 
    char* vertexShaderSourceCode = readFile("vertexShader.vs"); 
    char* fragmentShaderSourceCode = readFile("fragmentShader.fs"); 
    GLuint vertShaderID = makeVertexShader(vertexShaderSourceCode); 
    GLuint fragShaderID = makeFragmentShader(fragmentShaderSourceCode); 
    GLuint shaderProgramID = makeShaderProgram(vertShaderID, fragShaderID); 

    printf("vertShaderID is %d\n", vertShaderID); 
    printf("fragmentShaderID is %d\n", fragShaderID); 
    printf("shaderProgramID is %d\n", shaderProgramID); 
    #pragma endregion 

    //Create the "remember-all" 
    glGenVertexArrays(1, &vao); 
    glBindVertexArray(vao); 

    glGenBuffers(1, &vbo); 
    glBindBuffer(GL_ARRAY_BUFFER, vbo); 
    //Create buffer 
    glBufferData(GL_ARRAY_BUFFER, 7 * 3 * sizeof(GLfloat), NULL, GL_STATIC_DRAW); 
    //Load the vertex points 
    glBufferSubData(GL_ARRAY_BUFFER, 0, 3 * 3 * sizeof(GLfloat), vertices); 
    //Load the colors 
    glBufferSubData(GL_ARRAY_BUFFER, 3 * 3 * sizeof(GLfloat), 3 * 4 * sizeof(GLfloat), colors); 

    //Find variables in shader 
    positionID = glGetAttribLocation(shaderProgramID, "s_vPosition"); 
    colorID = glGetAttribLocation(shaderProgramID, "s_vColor"); 

    glVertexAttribPointer(positionID, 3, GL_FLOAT, GL_FALSE, 0, 0); 
    glVertexAttribPointer(colorID, 4, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(3 * 3 * sizeof(GLfloat))); 
    glUseProgram(shaderProgramID); 
    glEnableVertexAttribArray(positionID); 
    glEnableVertexAttribArray(colorID); 

    //Start up a loop that runs in the background 
    glutMainLoop(); 
    return 0; 
}

fragmentShader.fs

#version 130 

in vec4 color; 
out vec4 fColor; 

void main() { 
    fColor = color; 
}

vertexShader.vs

#version 130 

in vec4 s_vPosition; 
in vec4 s_vColor; 
out vec4 color; 

void main() { 
    //gl_Position = s_mP*s_mV*s_mM*s_vPosition; 
    color = s_vColor; 
    gl_Position = s_vPosition; 
}

来源

2016-02-28 Voxed

Ughh，我为创建这个遗憾。在睡觉之后再次查看我的代码，我意识到我所有的顶点都具有相同的“y值”。

GLfloat vertices[] = { 
    -0.5f, -0.5f, 0.0f, 
    0.5f, -0.5f, 0.0f, 
    0.0f, -0.5f, 0.0f 
};

无论如何，它已经解决了。上帝，我感到愚蠢。

来源

2016-02-28 09:50:42 Voxed

OpenGL的“黑屏”的渲染利用Shader

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