Question

我试图在OpenGL中绘制一个彩色正方形，但我只是看到了一些奇怪的彩色线条。它在我在着色器中手动设置颜色时有效，但在我将其作为属性发送时则无效。

这是我的最小，完整和可验证的例子。

#include <stdio.h>
#include <stdlib.h>
#include <GL/glew.h>
#include <GLFW/glfw3.h>

void glfw_framebuffer_size_callback(GLFWwindow *window, int width, int height)
{
    glViewport(0, 0, width, height);
}

int main()
{
    glfwInit();
    GLFWwindow *window = glfwCreateWindow(640, 480, "test", NULL, NULL);

    glfwMakeContextCurrent(window);
    glfwSetFramebufferSizeCallback(window, glfw_framebuffer_size_callback);
    glfwSwapInterval(0);

    glewExperimental = GL_TRUE;
    glewInit();

    GLuint vao;
    glGenVertexArrays(1, &vao);
    glBindVertexArray(vao);

    GLfloat verts[] = {-1.0f, 1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f, -1.0f};
    GLfloat color[] = {
        255.0f, 0.0f, 0.0f, 1.0f,
        0.0f, 255.0f, 0.0f, 1.0f,
        0.0f, 0.0f, 255.0f, 1.0f,
        255.0f, 255.0f, 0.0f, 1.0f
    };

    GLuint verts_vbo;
    glGenBuffers(1, &verts_vbo);
    glBindBuffer(GL_ARRAY_BUFFER, verts_vbo);
    glBufferData(GL_ARRAY_BUFFER, sizeof(verts), verts, GL_STATIC_DRAW);

    GLuint color_vbo;
    glGenBuffers(1, &color_vbo);
    glBindBuffer(GL_ARRAY_BUFFER, color_vbo);
    glBufferData(GL_ARRAY_BUFFER, sizeof(color), color, GL_STATIC_DRAW);

    const GLchar *v_shader_source =
        "#version 330 core\n"
        "in vec4 vcoords;"
        "in vec4 color;"
        "out vec4 frag_color;"
        "uniform mat4 model, view, projection;"
        "void main() { gl_Position = vcoords;"
        "frag_color = color; }";

    const GLchar *f_shader_source =
        "#version 330 core\n"
        "in vec4 frag_color;"
        "out vec4 final_color;"
        "void main() { final_color = frag_color; }";

    GLuint vs = glCreateShader(GL_VERTEX_SHADER);
    GLuint fs = glCreateShader(GL_FRAGMENT_SHADER);

    glShaderSource(vs, 1, &v_shader_source, NULL);
    glShaderSource(fs, 1, &f_shader_source, NULL);

    glCompileShader(vs);
    glCompileShader(fs);

    GLuint shader = glCreateProgram();
    glAttachShader(shader, vs);
    glAttachShader(shader, fs);
    glLinkProgram(shader);
    glDeleteShader(vs);
    glDeleteShader(fs);

    glUseProgram(shader);

    GLuint verts_index = glGetAttribLocation(shader, "vcoords");
    glEnableVertexAttribArray(verts_index);
    glBindBuffer(GL_ARRAY_BUFFER, verts_vbo);
    glVertexAttribPointer(verts_index, 2, GL_FLOAT, GL_FALSE, 0, NULL);

    GLuint color_index = glGetAttribLocation(shader, "color");
    glEnableVertexAttribArray(color_index);
    glBindBuffer(GL_ARRAY_BUFFER, color_vbo);
    glVertexAttribPointer(color_index, 4, GL_FLOAT, GL_FALSE, 0, NULL);

    while (!glfwWindowShouldClose(window))
    {
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
        glfwSwapBuffers(window);
        glfwWaitEvents();
    }

    glDeleteProgram(shader);

    return 0;
}

这就是结果：

我做错了什么？

代码仍然太长而无法添加更多文字但我不知道还有什么要说的。

OpenGL奇怪的颜色

0 个答案: