test_shader.cpp

#include <softrender/glSoft.h>
#include "utils/TestUtil.h"
#include "program/shader.h"
#include <cmath>

class TestShader:public TestUtil
{
public:
    int GetProgram0()
    {
        const char *vertexShaderSource ="#version 330 core\n"
            "layout (location = 0) in vec3 aPos;\n"
            "void main()\n"
            "{\n"
            "   gl_Position = vec4(aPos, 1.0);\n"
            "}\n";

        const char *fragmentShaderSource = "#version 330 core\n"
            "out vec4 FragColor;\n"
            "uniform vec4 ourColor;\n"
            "void main()\n"
            "{\n"
            "   FragColor = ourColor;\n"
            "}\n";

        unsigned int vertexShader;
        vertexShader = glCreateShader(GL_VERTEX_SHADER);
        glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
        glCompileShader(vertexShader);

        unsigned int fragmentShader;
        fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
        glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
        glCompileShader(fragmentShader);

        unsigned int shaderProgram;
        shaderProgram = glCreateProgram();
        glAttachShader(shaderProgram, vertexShader);
        glAttachShader(shaderProgram, fragmentShader);
        glLinkProgram(shaderProgram);
        glDeleteShader(vertexShader);
        glDeleteShader(fragmentShader);

        return shaderProgram;
    }
    int GetProgram1()
    {
        const char *vertexShaderSource ="#version 330 core\n"
            "layout (location = 0) in vec3 aPos;\n"
            "layout (location = 1) in vec3 aColor;\n"
            "out vec3 ourColor;\n"
            "void main()\n"
            "{\n"
            "   gl_Position = vec4(aPos, 1.0);\n"
            "   ourColor = aColor;\n"
            "}\0";

        const char *fragmentShaderSource = "#version 330 core\n"
            "out vec4 FragColor;\n"
            "in vec3 ourColor;\n"
            "void main()\n"
            "{\n"
            "   FragColor = vec4(ourColor, 1.0f);\n"
            "}\n\0";

        unsigned int vertexShader;
        vertexShader = glCreateShader(GL_VERTEX_SHADER);
        glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
        glCompileShader(vertexShader);

        unsigned int fragmentShader;
        fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
        glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
        glCompileShader(fragmentShader);

        unsigned int shaderProgram;
        shaderProgram = glCreateProgram();
        glAttachShader(shaderProgram, vertexShader);
        glAttachShader(shaderProgram, fragmentShader);
        glLinkProgram(shaderProgram);
        glDeleteShader(vertexShader);
        glDeleteShader(fragmentShader);

        return shaderProgram;
    }
    
    unsigned int GetVBO0()
    {
        float vertices[] = {
            0.5f, -0.5f, 0.0f,  // bottom right
            -0.5f, -0.5f, 0.0f,  // bottom left
            0.0f,  0.5f, 0.0f   // top 
        };
        unsigned int VBO;
        glGenBuffers(1, &VBO);
        glBindBuffer(GL_ARRAY_BUFFER, VBO); 
        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
        glEnableVertexAttribArray(0);
        glBindBuffer(GL_ARRAY_BUFFER, 0); 
        return VBO;
    }

    unsigned int GetVBO1()
    {
        float vertices[] = {
            // positions         // colors
            0.5f, -0.5f, 0.0f,  1.0f, 0.0f, 0.0f,  // bottom right
            -0.5f, -0.5f, 0.0f,  0.0f, 1.0f, 0.0f,  // bottom left
            0.0f,  0.5f, 0.0f,  0.0f, 0.0f, 1.0f   // top 

        };
        unsigned int VBO;
        glGenBuffers(1, &VBO);
        glBindBuffer(GL_ARRAY_BUFFER, VBO); 
        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

        // position attribute
        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
        glEnableVertexAttribArray(0);
        // color attribute
        glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3 * sizeof(float)));
        glEnableVertexAttribArray(1);

        glBindBuffer(GL_ARRAY_BUFFER, 0); 
        return VBO;
    }

};

TEST_F(TestShader, uniform)
{
    unsigned int VAO;
    glGenVertexArrays(1, &VAO);
    // 1. 绑定VAO
    glBindVertexArray(VAO);
    // 2. 把顶点数组复制到缓冲中供OpenGL使用
    unsigned int VBO=GetVBO0();

    int shaderProgram = GetProgram0();
    auto fn=[&](int frame)
    {
        glUseProgram(shaderProgram);
        // update shader uniform
        float greenValue = static_cast<float>(sin(frame) / 2.0 + 0.5);
        int vertexColorLocation = glGetUniformLocation(shaderProgram, "ourColor");
        glUniform4f(vertexColorLocation, 0.0f, greenValue, 0.0f, 1.0f);

        // render the triangle
        glDrawArrays(GL_TRIANGLES, 0, 3);
    };

    PlayWindow(fn,20);

    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);
    glDeleteProgram(shaderProgram);
}

TEST_F(TestShader, atribute)
{
    unsigned int VAO;
    glGenVertexArrays(1, &VAO);
    // 1. 绑定VAO
    glBindVertexArray(VAO);
    // 2. 把顶点数组复制到缓冲中供OpenGL使用
    unsigned int VBO=GetVBO1();

    int shaderProgram = GetProgram1();
    auto fn=[&](int frame)
    {
        glUseProgram(shaderProgram);
        // render the triangle
        glBindVertexArray(VAO);
        glDrawArrays(GL_TRIANGLES, 0, 3);
    };

    PlayWindow(fn,20);

    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);
    glDeleteProgram(shaderProgram);
}

TEST_F(TestShader, shader)
{
    unsigned int VAO;
    glGenVertexArrays(1, &VAO);
    // 1. 绑定VAO
    glBindVertexArray(VAO);
    // 2. 把顶点数组复制到缓冲中供OpenGL使用
    unsigned  VBO=GetVBO1();

    // build and compile our shader program
    // ------------------------------------
    Shader ourShader("driver/test_shader/shader.vs", "driver/test_shader/shader.fs"); // you can name your shader files however you like

    auto fn=[&](int frame)
    {
        ourShader.use();
        glBindVertexArray(VAO);
        glDrawArrays(GL_TRIANGLES, 0, 3);
    };

    PlayWindow(fn,20);

    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);
    glDeleteProgram(ourShader.ID);
}

TEST_F(TestShader, upsidedown)
{
    unsigned int VAO;
    glGenVertexArrays(1, &VAO);
    // 1. 绑定VAO
    glBindVertexArray(VAO);
    // 2. 把顶点数组复制到缓冲中供OpenGL使用
    unsigned  VBO=GetVBO1();

    // build and compile our shader program
    // ------------------------------------
    Shader ourShader("driver/test_shader/upsidedown.vs", "driver/test_shader/shader.fs"); // you can name your shader files however you like

    auto fn=[&](int frame)
    {
        ourShader.use();
        glBindVertexArray(VAO);
        glDrawArrays(GL_TRIANGLES, 0, 3);
    };

    PlayWindow(fn,20);

    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);
    glDeleteProgram(ourShader.ID);
}

TEST_F(TestShader, bias)
{
    unsigned int VAO;
    glGenVertexArrays(1, &VAO);
    // 1. 绑定VAO
    glBindVertexArray(VAO);
    // 2. 把顶点数组复制到缓冲中供OpenGL使用
    unsigned  VBO=GetVBO1();

    // build and compile our shader program
    // ------------------------------------
    Shader ourShader("driver/test_shader/bias.vs", "driver/test_shader/shader.fs"); // you can name your shader files however you like

    auto fn=[&](int frame)
    {
        ourShader.use();
        
        ourShader.setFloat("xOffset", frame%100*0.5f/100);

        glBindVertexArray(VAO);
        glDrawArrays(GL_TRIANGLES, 0, 3);
    };

    PlayWindow(fn,20);

    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);
    glDeleteProgram(ourShader.ID);
}

TEST_F(TestShader, inout)
{
    unsigned int VAO;
    glGenVertexArrays(1, &VAO);
    // 1. 绑定VAO
    glBindVertexArray(VAO);
    // 2. 把顶点数组复制到缓冲中供OpenGL使用
    unsigned  VBO=GetVBO1();

    // build and compile our shader program
    // ------------------------------------
    Shader ourShader("driver/test_shader/inout.vs", "driver/test_shader/inout.fs"); // you can name your shader files however you like

    auto fn=[&](int frame)
    {
        ourShader.use();
        glBindVertexArray(VAO);
        glDrawArrays(GL_TRIANGLES, 0, 3);
    };

    PlayWindow(fn,20);

    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);
    glDeleteProgram(ourShader.ID);
}