Question

前言，我正在使用Derelict在D中编写OpenGL。但是，它应该与使用C ++的OpenGL几乎相同，因为函数调用是相同的。无论如何，我不知道为什么我的代码不会在屏幕上打印任何东西，因为我的着色器程序没有错误。我很抱歉大代码转储，但我无法隔离问题。我的着色器类如下：

module shader;
import std.stdio;
import std.string;
import derelict.sdl2.sdl;
import derelict.opengl3.gl3;

class Shader
{
    this(string file_name)
    {
        // Load OpenGL versions 1.0 and 1.1.
        DerelictGL3.load();
        // Load versions 1.2+ and all supported ARB and EXT extensions.
        DerelictGL3.reload();

        program = glCreateProgram();

        shaders[0] = create_shader(load_shader(file_name ~ ".vs"), GL_VERTEX_SHADER);
        shaders[1] = create_shader(load_shader(file_name ~ ".fs"), GL_FRAGMENT_SHADER);

        for (int i = 0; i < NUM_SHADERS; i++)
            glAttachShader(program, shaders[i]);

        glBindAttribLocation(program, 0, "position"); 

        glLinkProgram(program);

        check_shader_error(program, GL_LINK_STATUS, true, "Error linking shader!");

        glValidateProgram(program);

        check_shader_error(program, GL_VALIDATE_STATUS, true, "Error invalid shader!");
    }
    void bind()
    {
        glUseProgram(program);
    }
    string load_shader(string shader_name) {
        string output;
        auto f = File(shader_name);         // open file for reading,
        scope(exit) f.close();              //   and close the file when we're done.
                                            //   (optional)
        foreach (str; f.byLine)             // read every line in the file,
        {
            output ~= str;
            output ~= "\n";
        }

        ///writeln(output);
        return output;                      //   and return it
    }
    GLuint create_shader(string text, GLenum shader_type)
    {
        GLuint shader = glCreateShader(shader_type);

        GLchar* shader_source_strings[1];
        GLint shader_source_strings_lengths[1];

        shader_source_strings[0] = cast(char*)(text);
        shader_source_strings_lengths[0] = (cast(int)text.length);

        glShaderSource(shader, 1, shader_source_strings.ptr, shader_source_strings_lengths.ptr);
        glCompileShader(shader);

        check_shader_error(shader, GL_COMPILE_STATUS, false, "Error compiling shader!");

        return shader;
    }
    void check_shader_error(GLuint shader, GLuint flag, bool isProgram, string error_message)
    {
        GLint success = 0;
        GLchar[1024] error;

        if (isProgram)
            glGetProgramiv(shader, flag, &success);
        else
            glGetShaderiv(shader, flag, &success);

        if (success == GL_FALSE)
        {
            if(isProgram)
                glGetProgramInfoLog(shader, error.sizeof, null, error.ptr);
            else
                glGetProgramInfoLog(shader, error.sizeof, null, error.ptr);
            writeln(error_message ~ error ~ "\n");
        }
    }
private:
    static const int NUM_SHADERS = 2;
    GLuint program;
    GLuint shaders[NUM_SHADERS];
}

我的Mesh课程是：

module mesh;    
import std.stdio;
import derelict.opengl3.gl3;
import vertex;
class Mesh
{
    this(Vertex* vertices, int num_vertices)
    {

        // Load OpenGL versions 1.0 and 1.1.
        DerelictGL3.load();
        // Load versions 1.2+ and all supported ARB and EXT extensions.
        DerelictGL3.reload();

        draw_count = num_vertices;

        glGenVertexArrays(1, &vertex_array_object);
        glBindVertexArray(vertex_array_object);

        glGenBuffers(NUM_BUFFERS, vertex_array_buffers.ptr);
        glBindBuffer(GL_ARRAY_BUFFER, vertex_array_buffers[POSITION_VB]);
        glBufferData(GL_ARRAY_BUFFER, num_vertices * vertices[0].sizeof, vertices, GL_STATIC_DRAW);

        glEnableVertexAttribArray(0);
        glVertexAttribPointer(cast(GLuint)0, 3, GL_FLOAT, GL_FALSE, 0, cast(void*)0);

        glBindVertexArray(0);
    }
    void draw()
    {
        glBindVertexArray(vertex_array_object);

        glDrawArrays(GL_TRIANGLES, 0, draw_count);

        glBindVertexArray(0);
    }
private:
    enum 
    {
        POSITION_VB,
        NUM_BUFFERS
    };

    GLuint vertex_array_object;
    GLuint vertex_array_buffers[NUM_BUFFERS];
    int draw_count;
}

Answer 1

我找到了答案，当我使用我正在使用的函数加载器（Derelict）加载OpenGL库时，我有一些冗余调用，而且我错误地表示了我的顶点数组。我在数字火星论坛上找到了帮助here。

为什么这个OpenGL代码没有错误但是没有任何内容可以打印到屏幕上

1 个答案: