"https://open.gl/"教程之Transforms源码(freeglut版)

以上一节Textures代码为基础，没变的部分用灰色表示。

VERTEX_SHADER:

#version 150 core

in vec2 position;
in vec3 color;
in vec2 texcoord;

out vec3 Color;
out vec2 TexCoord;

uniform mat4 trans;
uniform mat4 view;
uniform mat4 project;
void main(){
    Color=color;
    TexCoord=texcoord;
    //gl_Position=trans*vec4(position,0,1);
    //只设置view，没设置project什么都看不大
    //gl_Position=view*trans*vec4(position,0,1);
    gl_Position=project*view*trans*vec4(position,0,1);
}

FRAGEMENT_SHADER:

#version 150 core

in vec3 Color;
in vec2 TexCoord;

out vec4 outColor;

uniform sampler2D texKit;
uniform sampler2D texPupy;

uniform vec3 triangleColor;
void main(){
    //outColor=texture(texKit,TexCoord)*vec4(Color,1.0);
    vec4 colKit=texture(texKit,TexCoord);
    vec4 colPupy=texture(texPupy,TexCoord);
    outColor=mix(colKit,colPupy,0.2);
}

源码：

#include"glew.h"
#include<Windows.h>
#include"freeglut.h"
#include<glGL.h>
#include<random>
#include"LoadShaders.h"
#include"SOIL.h"

#include"glmglm.hpp"
#include"glmgtcmatrix_transform.hpp"
#include"glmgtc	ype_ptr.hpp"
GLuint vao;
GLuint vbo;
GLuint ebo;
GLuint tbo[2];
//translate
GLuint uniTransLoc;
glm::mat4 trans;        //初始化一个单位矩阵

void Init(){
    GLfloat vertices[] = {
        -0.5, 0.5, 1.0, 0.0, 0.0, 0.0, 0.0,
        0.5, 0.5, 0.0, 1.0, 0.0, 1.0, 0.0,
        0.5, -0.5, 0.0, 0.0, 1.0, 1.0, 1.0,
        -0.5, -0.5, 1.0, 1.0, 1.0, 0.0, 1.0

    };

    GLuint elements[] = { 0, 1, 2, 2, 3, 0 };
    ShaderInfo shaders[] = {
        { GL_VERTEX_SHADER, "vertexShader.txt" },
        { GL_FRAGMENT_SHADER, "fragementShader.txt" },
        { GL_NONE, NULL }
    };
    GLuint shaderProgram = LoadShaders(shaders);
    //**VAO开始记录
    glGenVertexArrays(1, &vao);
    glBindVertexArray(vao);
    //*VBO,需要数据配接
    glGenBuffers(1, &vbo);
    glBindBuffer(GL_ARRAY_BUFFER, vbo);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

    //*数据配接
    glUseProgram(shaderProgram);

    GLuint posAttri = glGetAttribLocation(shaderProgram, "position");
    glVertexAttribPointer(posAttri, 2, GL_FLOAT, GL_FALSE, 7 * sizeof(GL_FLOAT), 0);
    glEnableVertexAttribArray(posAttri);

    GLuint colorAttri = glGetAttribLocation(shaderProgram, "color");
    glVertexAttribPointer(colorAttri, 3, GL_FLOAT, GL_FALSE, 7 * sizeof(GL_FLOAT), (void*)(2 * sizeof(GL_FLOAT)));
    glEnableVertexAttribArray(colorAttri);

    GLuint texAttri = glGetAttribLocation(shaderProgram, "texcoord");
    glVertexAttribPointer(texAttri, 2, GL_FLOAT, GL_FALSE, 7 * sizeof(GL_FLOAT), (void*)(5 * sizeof(GL_FLOAT)));
    glEnableVertexAttribArray(texAttri);

    //*EBO
    glGenBuffers(1, &ebo);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(elements), elements, GL_STATIC_DRAW);
    //*TBO
    glGenTextures(2, tbo);
    int width = 0, height = 0;
    unsigned char* image;

    glActiveTexture(GL_TEXTURE0);        //对应samplerD texKit
    glBindTexture(GL_TEXTURE_2D, tbo[0]);
    image = SOIL_load_image("sample.png", &width, &height, 0, SOIL_LOAD_RGB);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, image);
    SOIL_free_image_data(image);
    glUniform1i(glGetUniformLocation(shaderProgram, "texKit"), 0);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);


    glActiveTexture(GL_TEXTURE1);        //对应samplerD texPupy
    glBindTexture(GL_TEXTURE_2D, tbo[1]);
    image = SOIL_load_image("sample2.png", &width, &height, 0, SOIL_LOAD_RGB);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, image);
    SOIL_free_image_data(image);
    glUniform1i(glGetUniformLocation(shaderProgram, "texPupy"), 1);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    //**translation
    //trans = glm::rotate(trans, glm::radians(5.f), glm::vec3(0.0f, 0.f, 1.f));
    uniTransLoc = glGetUniformLocation(shaderProgram, "trans");
    glUniformMatrix4fv(uniTransLoc, 1, GL_FALSE, glm::value_ptr(trans));
    //*view 默认eye(0.f,0.f,0.f),center(0.f,0.f,-1.f),up(0.f,1.f,0.f)
    glm::mat4 view=glm::lookAt(glm::vec3(1.2f, 1.2f, 1.2f), glm::vec3(0.f, 0.f, 0.f), glm::vec3(0.f, 0.f, 1.f));
    GLuint uniViewLoc = glGetUniformLocation(shaderProgram, "view");
    glUniformMatrix4fv(uniViewLoc, 1, GL_FALSE, glm::value_ptr(view));
    //*project 3D中一定要设置投影，否则看不到
    glm::mat4 project = glm::perspective(glm::radians(45.f), 1.f, 1.f, 100.f);
    GLuint uniProjectLoc = glGetUniformLocation(shaderProgram, "project");
    glUniformMatrix4fv(uniProjectLoc, 1, GL_FALSE, glm::value_ptr(project));

    glClearColor(0, 0, 0, 1);
}
void Display(){
    glClear(GL_COLOR_BUFFER_BIT);
    glBindVertexArray(vao);
    //glDrawArrays(GL_TRIANGLES, 0, 3);
    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
    //glDrawElementsBaseVertex(GL_TRIANGLES, 3, GL_UNSIGNED_INT, 0, 1);
    glFlush();
}
void KeyboardFunc(unsigned char c, int x, int){
    switch (c)
    {
    case 'x':
    case 'X':
        trans = glm::rotate(trans, glm::radians(5.f), glm::vec3(1.f, 0.f, 0.f));
    case 'y':
    case 'Y':
        trans = glm::rotate(trans, glm::radians(5.f), glm::vec3(0.f, 1.f, 0.f));
    case 'z':
    case 'Z':
        trans = glm::rotate(trans, glm::radians(5.f), glm::vec3(0.f, 0.f, 1.f));
    default:
        break;
    }
    glUniformMatrix4fv(uniTransLoc, 1, GL_FALSE, glm::value_ptr(trans));
    glutPostRedisplay();
}
int main(int argc, char** argv){
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGBA);
    glutInitWindowSize(512, 512);
    glutInitWindowPosition(100, 200);
    glutInitContextVersion(3, 2);
    glutInitContextProfile(GLUT_CORE_PROFILE);
    glutCreateWindow(argv[0]);
    glewExperimental = true;
    glewInit();
    Init();
    glutDisplayFunc(Display);
    glutKeyboardFunc(KeyboardFunc);
    glutMainLoop();
    return 0;
}