c – 为什么精灵不能在OpenGL中渲染？

顺便说一句,这是源代码(没有调试,简而言之)： –

main.cpp中

// Including all required headers here...

#include <iostream>

#define GLEW_STATIC
#include <GL/glew.h>

#include <GLFW/glfw3.h>

#include "SOIL2/SOIL2.h"

#include <glm/glm.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <glm/gtc/matrix_transform.hpp>

const GLchar * vertexShaderSource =
    "#version 330 coren"
    "layout(location = 0) in vec4 vertex;n"
    "out vec2 TexCoords;n"
    "uniform mat4 model;n"
    "uniform mat4 projection;n"
    "void main()n"
    "{n"
    "TexCoords = vertex.zw;n"
    "gl_Position = projection * model * vec4(vertex.xy,0.0,1.0);n"
    "}";

const GLchar * fragmentShaderSource =
    "#version 330 coren"
    "in vec2 TexCoords;n"
    "out vec4 color;n"
    "uniform sampler2D image;n"
    "uniform vec3 spriteColor;n"
    "void main()n"
    "{n"
    "color = vec4(spriteColor,1.0) * texture(image,TexCoords);n"
    "}";

const GLint WIDTH = 800,HEIGHT = 600;

int main()
{
    glfwInit();

    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR,3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR,3);
    glfwWindowHint(GLFW_OPENGL_PROFILE,GLFW_OPENGL_CORE_PROFILE);
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT,GLFW_FALSE);

    glfwWindowHint(GLFW_RESIZABLE,GL_FALSE);

    GLFWwindow *window = glfwCreateWindow(WIDTH,HEIGHT,"Rendering Sprites",nullptr,nullptr);

    int screenWidth,screenHeight;
    glfwGetFramebufferSize(window,&screenWidth,&screenHeight);

    glfwMakeContextCurrent(window);

    glewExperimental = GL_TRUE;
    glewInit();

    glViewport(0,screenWidth,screenHeight);

    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);

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

    GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
    glShaderSource(fragmentShader,&fragmentShaderSource,NULL);
    glCompileShader(fragmentShader);

    GLuint shaderProgram = glCreateProgram();
    glAttachShader(shaderProgram,vertexShader);
    glAttachShader(shaderProgram,fragmentShader);
    glLinkProgram(shaderProgram);

    glDeleteShader(vertexShader);
    glDeleteShader(fragmentShader);

    GLuint quadVAO;
    GLuint VBO;
    GLfloat vertices[] =
    {
        0.0f,1.0f,0.0f,0.0f
    };

    glGenVertexArrays(1,&quadVAO);
    glGenBuffers(1,&VBO);

    glBindBuffer(GL_ARRAY_BUFFER,VBO);
    glBufferData(GL_ARRAY_BUFFER,sizeof(vertices),vertices,GL_STATIC_DRAW);

    glBindVertexArray(quadVAO);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(0,4,GL_FLOAT,GL_FALSE,4 * sizeof(GLfloat),(GLvoid*)0);
    glBindBuffer(GL_ARRAY_BUFFER,0);
    glBindVertexArray(0);

    GLuint texture;

    int width,height;

    glGenTextures(1,&texture);
    glBindTexture(GL_TEXTURE_2D,texture);

    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);

    unsigned char *image = SOIL_load_image("img.png",&width,&height,SOIL_LOAD_RGBA);
    glTexImage2D(GL_TEXTURE_2D,GL_RGBA,width,height,GL_UNSIGNED_BYTE,image);
    SOIL_free_image_data(image);
    glBindTexture(GL_TEXTURE_2D,0);

    while (!glfwWindowShouldClose(window))
    {
        glfwPollEvents();

        glClearColor(0.2f,0.3f,1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        glUseProgram(shaderProgram);
        glm::mat4 model;
        glm::mat4 projection = glm::ortho(0.0f,static_cast<GLfloat>(WIDTH),static_cast<GLfloat>(HEIGHT),-1.0f,1.0f);

        glm::vec2 size = glm::vec2(10.0f,10.0f);
        glm::vec2 position = glm::vec2(-10.0f,10.0f);
        glm::vec3 color = glm::vec3(1.0f,0.0f);
        GLfloat rotation = 0.0f;

        model = glm::translate(model,glm::vec3(position,0.0f));

        model = glm::translate(model,glm::vec3(0.5f * size.x,0.5f * size.y,0.0f));
        model = glm::rotate(model,rotation,glm::vec3(0.0f,1.0f));
        model = glm::translate(model,glm::vec3(-0.5f * size.x,-0.5f * size.y,0.0f));

        model = glm::scale(model,glm::vec3(size,1.0f));

        glUniformMatrix4fv(glGetUniformLocation(shaderProgram,"projection"),glm::value_ptr(projection));
        glUniformMatrix4fv(glGetUniformLocation(shaderProgram,"model"),glm::value_ptr(model));
        glUniform3f(glGetUniformLocation(shaderProgram,"spriteColor"),color.x,color.y,color.z);

        glActiveTexture(GL_TEXTURE0);
        glBindTexture(GL_TEXTURE_2D,texture);

        glBindVertexArray(quadVAO);
        glDrawArrays(GL_TRIANGLES,6);
        glBindVertexArray(0);

        glfwSwapBuffers(window);
    }

    glDeleteVertexArrays(1,&quadVAO);
    glDeleteBuffers(1,&VBO);

    glfwTerminate();

    return EXIT_SUCCESS;
}