渲染到纹理

完整程序
https://github.com/WaldenPonder/opengl-test/tree/master/t003

/* 帧缓冲,  渲染到纹理*/#include "stdafx.h"#include "../common/common.out.h"/*VAO VBO EBO   纹理*/using namespace std;float color1 = 0.1;float color2 = 0.3;float color3 = 0.4;bool g_b_line = false;void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode){    if (key == GLFW_KEY_1)    {        color1 = float(rand() % 255) / 255.0;    }    else if (key == GLFW_KEY_2)    {        color2 = float(rand() % 255) / 255.0;    }    else if (key == GLFW_KEY_3)    {        color3 = float(rand() % 255) / 255.0;    }    else if (key == GLFW_KEY_A)    {        glm::vec3 axis(0, 0, 1);        g_Mat4 = glm::rotate(g_Mat4, 3.0f, axis);    }    else if (key == GLFW_KEY_B)    {        glm::vec3 axis(0, 1, 0);        g_Mat4 = glm::rotate(g_Mat4, 3.0f, axis);    }    else if (key == GLFW_KEY_C)    {        glm::vec3 axis(1, 0, 0);        g_Mat4 = glm::rotate(g_Mat4, 3.0f, axis);    }    else if (key == GLFW_KEY_D)    {        glm::vec3 axis(1, 0, 0);        g_Mat4 = glm::translate(g_Mat4, axis);    }    else if (key == GLFW_KEY_E)    {        glm::vec3 axis(0, 1, 0);        g_Mat4 = glm::translate(g_Mat4, axis);    }    else if (key == GLFW_KEY_F)    {        glm::vec3 axis(0, 0, 1);        g_Mat4 = glm::translate(g_Mat4, axis);    }    else if (key == GLFW_KEY_W && action == 1)    {        g_b_line = !g_b_line;    }}GLfloat quadVertices[] ={    // Positions   // TexCoords    -1.0f, 1.0f, 0.0f, 1.0f,    -1.0f, -1.0f, 0.0f, 0.0f,    1.0f, -1.0f, 1.0f, 0.0f,    -1.0f, 1.0f, 0.0f, 1.0f,    1.0f, -1.0f, 1.0f, 0.0f,    1.0f, 1.0f, 1.0f, 1.0f};int main(){    GLfloat cubePts[180];    tools::GetCubePts_withTexture(cubePts);    glfwInit();    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);    glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);    GLFWwindow* window = glfwCreateWindow(1200, 900, "learn opengl", nullptr, nullptr);    glfwMakeContextCurrent(window);    glewInit();    int w, h;    glfwGetFramebufferSize(window, &w, &h);    glViewport(0, 0, w, h);    glfwSetKeyCallback(window, key_callback);    GLuint VAO, VBO;    {        glGenVertexArrays(1, &VAO);        glGenBuffers(1, &VBO);        glBindVertexArray(VAO);        glBindBuffer(GL_ARRAY_BUFFER, VBO);        glBufferData(GL_ARRAY_BUFFER, sizeof(cubePts), cubePts, GL_STATIC_DRAW);        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * FLOAT_SIZE, (void*)0);        glEnableVertexAttribArray(0);        glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * FLOAT_SIZE, (void*) (3 * FLOAT_SIZE ));        glEnableVertexAttribArray(1);        glBindVertexArray(0);        glBindBuffer(GL_ARRAY_BUFFER, 0);        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);    }    GLuint quadVAO, quadVBO;    {        glGenVertexArrays(1, &quadVAO);        glGenBuffers(1, &quadVBO);        glBindVertexArray(quadVAO);        glBindBuffer(GL_ARRAY_BUFFER, quadVBO);        glBufferData(GL_ARRAY_BUFFER, sizeof(quadVertices), quadVertices, GL_STATIC_DRAW);        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(GLfloat), (GLvoid*)0);        glEnableVertexAttribArray(0);        glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(GLfloat), (GLvoid*)(2 * sizeof(GLfloat)));        glEnableVertexAttribArray(1);        glBindBuffer(GL_ARRAY_BUFFER, 0);        glBindVertexArray(0);    }    GLuint frambuffer, texColorBuffer;    {        glGenFramebuffers(1, &frambuffer);        glBindFramebuffer(GL_FRAMEBUFFER, frambuffer);        glGenTextures(1, &texColorBuffer);        glBindTexture(GL_TEXTURE_2D, texColorBuffer);        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 1200, 900, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);        glBindTexture(GL_TEXTURE_2D, 0);        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texColorBuffer, 0);        // 生成一个渲染缓存对象#if 0        GLuint rbo;        glGenRenderbuffers(1, &rbo);        glBindRenderbuffer(GL_RENDERBUFFER, rbo);        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, 1200, 900);        glBindRenderbuffer(GL_RENDERBUFFER, 0);        // 把渲染缓冲对象附加到深度模板附件上        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, rbo);#endif        if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)            cout << "frame buffer uncompleted " << endl;        glBindFramebuffer(GL_FRAMEBUFFER, 0);    }    GLuint texture = tools::CreateTexture("../common/src/container.jpg", GL_REPEAT, GL_LINEAR);    Shader shader("vert003.v", "frag003.f");    Shader shaderNew("vert003new.v", "frag003new.f");    g_Mat4 = glm::mat4(1.0);    while (!glfwWindowShouldClose(window))    {        glfwPollEvents();        //1        glBindFramebuffer(GL_FRAMEBUFFER, frambuffer);        glClearColor(color1, color2, color3, 1);        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);        glPolygonMode(GL_FRONT_AND_BACK, g_b_line ? GL_LINE : GL_FILL);        glEnable(GL_DEPTH_TEST);        //glDepthFunc(GL_ALWAYS);        glEnable(GL_CULL_FACE);        glFrontFace(GL_CCW);        glCullFace(GL_BACK);        shader.Use();        shader.setUniformMat4f("vert_mat", g_Mat4);        shader.setUniformTexture2D("samp", texture, 0);        glBindVertexArray(VAO);        glDrawArrays(GL_TRIANGLES, 0, 36);        glBindVertexArray(0);        //2        glBindFramebuffer(GL_FRAMEBUFFER, 0);        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);        glClearColor(1, 1, 1, 1);        glDisable(GL_DEPTH_TEST);        shaderNew.Use();        shaderNew.setUniformTexture2D("sampNew", texColorBuffer, 0);        glBindVertexArray(quadVAO);        glDrawArrays(GL_TRIANGLES, 0, 6);        glBindVertexArray(0);        glfwSwapBuffers(window);    }    glfwTerminate();    return 0;}