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Copy pathvertData.cpp
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Copy pathvertData.cpp
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393 lines (365 loc) · 12.6 KB
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// 引入GLEW库 定义静态链接
#define GLEW_STATIC
#include <GLEW/glew.h>
// 引入GLFW库
#include <GLFW/glfw3.h>
// 引入SOIL库
#include <SOIL/SOIL.h>
#include <iostream>
#include <vector>
// 包含着色器加载库
#include "shader.h"
// 包含纹理加载辅助类
#include "texture.h"
// 键盘回调函数原型声明
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods);
// 定义程序常量
const int WINDOW_WIDTH = 800, WINDOW_HEIGHT = 600;
GLfloat colorMixValue = 0.5;
// 不同的顶点属性数据传送方式
// 这些例子主要用于展示函数用法 实际使用视具体情况而定
void prepareVertData_moreVBO(GLuint& VAOId, std::vector<GLuint>& VBOIdVec);
void prepareVertData_seqBatchVBO(GLuint& VAOId, std::vector<GLuint>& VBOIdVec);
void prepareVertData_interleavedBatchVBO(GLuint& VAOId, std::vector<GLuint>& VBOIdVec);
void prepareVertData_glBufferSubData(GLuint& VAOId, std::vector<GLuint>& VBOIdVec);
void prepareVertData_glMapBuffer(GLuint& VAOId, std::vector<GLuint>& VBOIdVec);
void prepareVertData_glCopyBufferSubData(GLuint& VAOId, std::vector<GLuint>& VBOIdVec);
int main(int argc, char** argv)
{
if (!glfwInit()) // 初始化glfw库
{
std::cout << "Error::GLFW could not initialize GLFW!" << std::endl;
return -1;
}
// 开启OpenGL 3.3 core profile
std::cout << "Start OpenGL core profile version 3.3" << std::endl;
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);
// 创建窗口
GLFWwindow* window = glfwCreateWindow(WINDOW_WIDTH, WINDOW_HEIGHT,
"Demo of vertex attribute data(press A S to mix color)", NULL, NULL);
if (!window)
{
std::cout << "Error::GLFW could not create winddow!" << std::endl;
glfwTerminate();
return -1;
}
// 创建的窗口的context指定为当前context
glfwMakeContextCurrent(window);
// 注册窗口键盘事件回调函数
glfwSetKeyCallback(window, key_callback);
// 初始化GLEW 获取OpenGL函数
glewExperimental = GL_TRUE; // 让glew获取所有拓展函数
GLenum status = glewInit();
if (status != GLEW_OK)
{
std::cout << "Error::GLEW glew version:" << glewGetString(GLEW_VERSION)
<< " error string:" << glewGetErrorString(status) << std::endl;
glfwTerminate();
return -1;
}
// 设置视口参数
glViewport(0, 0, WINDOW_WIDTH, WINDOW_HEIGHT);
// section1 准备顶点属性数据
GLuint VAOId;
std::vector<GLuint> VBOIdVec;
prepareVertData_glCopyBufferSubData(VAOId, VBOIdVec); // 替换这个方法以观察其他方式
// Section2 准备着色器程序
Shader shader("triangle.vertex", "triangle.frag");
// Section3 准备纹理对象
GLint textureId = TextureHelper::load2DTexture("../../resources/textures/window.png");
// 开始游戏主循环
while (!glfwWindowShouldClose(window))
{
glfwPollEvents(); // 处理例如鼠标 键盘等事件
// 清除颜色缓冲区 重置为指定颜色
glClearColor(0.18f, 0.04f, 0.14f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
// 这里填写场景绘制代码
glBindVertexArray(VAOId);
shader.use();
// 启用纹理单元 绑定纹理对象
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, textureId);
glUniform1i(glGetUniformLocation(shader.programId, "tex"), 0); // 设置纹理单元为0号
glUniform1f(glGetUniformLocation(shader.programId, "colorMixValue"), colorMixValue);
glDrawArrays(GL_TRIANGLES, 0, 3);
glBindVertexArray(0);
glUseProgram(0);
glfwSwapBuffers(window); // 交换缓存
}
// 释放资源
glDeleteVertexArrays(1, &VAOId);
for (std::vector<GLuint>::const_iterator it = VBOIdVec.begin();
VBOIdVec.end() != it; ++ it)
{
glDeleteBuffers(1, &(*it));
}
glfwTerminate();
return 0;
}
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
{
if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
{
glfwSetWindowShouldClose(window, GL_TRUE); // 关闭窗口
}
else if (key == GLFW_KEY_S && action == GLFW_PRESS)
{
colorMixValue += 0.05f;
if (colorMixValue > 1.0f)
colorMixValue = 1.0f;
}
else if (key == GLFW_KEY_A && action == GLFW_PRESS)
{
colorMixValue -= 0.05f;
if (colorMixValue < 0.0f)
colorMixValue = 0.0f;
}
}
// 顶点属性每个独立的VBO
void prepareVertData_moreVBO(GLuint& VAOId, std::vector<GLuint>& VBOIdVec)
{
// 单个属性独立
GLfloat vertPos[] = {
-0.5f, 0.0f, 0.0f, 0.5f, 0.0f, 0.0f, 0.0f, 0.5f, 0.0f, // 顶点位置
};
GLfloat vertColor[] = {
1.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, // 颜色
};
GLfloat vertTextCoord[] = {
0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f // 纹理坐标
};
// 创建缓存对象
GLuint VBOId[3];
// Step1: 创建并绑定VAO对象
glGenVertexArrays(1, &VAOId);
glBindVertexArray(VAOId);
glGenBuffers(3, VBOId);
// 顶点位置属性
glBindBuffer(GL_ARRAY_BUFFER, VBOId[0]);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertPos), vertPos, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray(0);
// 顶点颜色属性
glBindBuffer(GL_ARRAY_BUFFER, VBOId[1]);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertColor), vertColor, GL_STATIC_DRAW);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray(1);
// 顶点纹理坐标
glBindBuffer(GL_ARRAY_BUFFER, VBOId[2]);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertTextCoord), vertTextCoord, GL_STATIC_DRAW);
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray(2);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
VBOIdVec.push_back(VBOId[0]);
VBOIdVec.push_back(VBOId[1]);
VBOIdVec.push_back(VBOId[2]);
}
// 顶点属性单个连续的整体VBO
void prepareVertData_seqBatchVBO(GLuint& VAOId, std::vector<GLuint>& VBOIdVec)
{
// 单个属性连续作为整体
GLfloat vertices[] = {
-0.5f, 0.0f, 0.0f, 0.5f, 0.0f, 0.0f, 0.0f, 0.5f, 0.0f, // 顶点位置
1.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, // 颜色
0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f // 纹理坐标
};
// 创建缓存对象
GLuint VBOId;
// Step1: 创建并绑定VAO对象
glGenVertexArrays(1, &VAOId);
glBindVertexArray(VAOId);
// Step2: 创建并绑定VBO 对象 传送数据
glGenBuffers(1, &VBOId);
glBindBuffer(GL_ARRAY_BUFFER, VBOId);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
// Step3: 指定解析方式 并启用顶点属性
// 顶点位置属性
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (GLvoid*)0); // 紧密排列 stride也可以设置为 3 * sizeof(GL_FLOAT)
glEnableVertexAttribArray(0);
// 顶点颜色属性
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, (GLvoid*)(9 * sizeof(GL_FLOAT)));
glEnableVertexAttribArray(1);
// 顶点纹理坐标
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 0, (GLvoid*)(18 * sizeof(GL_FLOAT)));
glEnableVertexAttribArray(2);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
VBOIdVec.push_back(VBOId);
}
// 顶点属性之间交错的整体VBO
void prepareVertData_interleavedBatchVBO(GLuint& VAOId, std::vector<GLuint>& VBOIdVec)
{
// 交错指定顶点属性数据
GLfloat vertices[] = {
// 顶点位置 颜色 纹理纹理
-0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, // 0
0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // 1
0.0f, 0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, // 2
};
// 创建缓存对象
GLuint VBOId;
// Step1: 创建并绑定VAO对象
glGenVertexArrays(1, &VAOId);
glBindVertexArray(VAOId);
// Step2: 创建并绑定VBO 对象 传送数据
glGenBuffers(1, &VBOId);
glBindBuffer(GL_ARRAY_BUFFER, VBOId);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
// Step3: 指定解析方式 并启用顶点属性
// 顶点位置属性
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE,8 * sizeof(GL_FLOAT), (GLvoid*)0);
glEnableVertexAttribArray(0);
// 顶点颜色属性
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE,
8 * sizeof(GL_FLOAT),(GLvoid*)(3 * sizeof(GL_FLOAT)));
glEnableVertexAttribArray(1);
// 顶点纹理坐标
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE,
8 * sizeof(GL_FLOAT), (GLvoid*)(6 * sizeof(GL_FLOAT)));
glEnableVertexAttribArray(2);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
VBOIdVec.push_back(VBOId);
}
// 使用glBufferSubData完成VBO
void prepareVertData_glBufferSubData(GLuint& VAOId, std::vector<GLuint>& VBOIdVec)
{
// 单个属性独立
GLfloat vertPos[] = {
-0.5f, 0.0f, 0.0f, 0.5f, 0.0f, 0.0f, 0.0f, 0.5f, 0.0f, // 顶点位置
};
GLfloat vertColor[] = {
1.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, // 颜色
};
GLfloat vertTextCoord[] = {
0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f // 纹理坐标
};
// 创建缓存对象
GLuint VBOId;
// Step1: 创建并绑定VAO对象
glGenVertexArrays(1, &VAOId);
glBindVertexArray(VAOId);
// Step2: 创建并绑定VBO 对象 预分配空间
glGenBuffers(1, &VBOId);
glBindBuffer(GL_ARRAY_BUFFER, VBOId);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertPos)+sizeof(vertColor) + sizeof(vertTextCoord),
NULL, GL_STATIC_DRAW); // 预分配空间
// Step3: 填充具体的数据
glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertPos), vertPos);
glBufferSubData(GL_ARRAY_BUFFER, sizeof(vertPos), sizeof(vertColor), vertColor);
glBufferSubData(GL_ARRAY_BUFFER, sizeof(vertPos)+ sizeof(vertColor), sizeof(vertTextCoord), vertTextCoord);
// Step4: 指定解析方式 并启用顶点属性
// 顶点位置属性
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (GLvoid*)0); // 紧密排列 stride也可以设置为 3 * sizeof(GL_FLOAT)
glEnableVertexAttribArray(0);
// 顶点颜色属性
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, (GLvoid*)(9 * sizeof(GL_FLOAT)));
glEnableVertexAttribArray(1);
// 顶点纹理坐标
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 0, (GLvoid*)(18 * sizeof(GL_FLOAT)));
glEnableVertexAttribArray(2);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
VBOIdVec.push_back(VBOId);
}
// 使用glMapBuffer
void prepareVertData_glMapBuffer(GLuint& VAOId, std::vector<GLuint>& VBOIdVec)
{
// 交错指定顶点属性数据
GLfloat vertices[] = {
// 顶点位置 颜色 纹理纹理
-0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, // 0
0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // 1
0.0f, 0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, // 2
};
// 创建缓存对象
GLuint VBOId;
// Step1: 创建并绑定VAO对象
glGenVertexArrays(1, &VAOId);
glBindVertexArray(VAOId);
// Step2: 创建并绑定VBO 对象
glGenBuffers(1, &VBOId);
glBindBuffer(GL_ARRAY_BUFFER, VBOId);
// Step3: 映射数据
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), NULL, GL_STATIC_DRAW); // 预分配空间
void* ptr = glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
if (!ptr)
{
std::cerr << " map buffer failed!" << std::endl;
return;
}
memcpy(ptr, vertices, sizeof(vertices)); // 可以操作这个指针指向的内存空间
glUnmapBuffer(GL_ARRAY_BUFFER);
// Step4: 指定解析方式 并启用顶点属性
// 顶点位置属性
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GL_FLOAT), (GLvoid*)0);
glEnableVertexAttribArray(0);
// 顶点颜色属性
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE,
8 * sizeof(GL_FLOAT), (GLvoid*)(3 * sizeof(GL_FLOAT)));
glEnableVertexAttribArray(1);
// 顶点纹理坐标
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE,
8 * sizeof(GL_FLOAT), (GLvoid*)(6 * sizeof(GL_FLOAT)));
glEnableVertexAttribArray(2);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
VBOIdVec.push_back(VBOId);
}
// 使用glCopyBufferSubData
void prepareVertData_glCopyBufferSubData(GLuint& VAOId, std::vector<GLuint>& VBOIdVec)
{
// 交错指定顶点属性数据
GLfloat vertices[] = {
// 顶点位置 颜色 纹理纹理
-0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, // 0
0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // 1
0.0f, 0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, // 2
};
// 创建缓存对象
GLuint VBOId;
// Step1: 创建并绑定VAO对象
glGenVertexArrays(1, &VAOId);
glBindVertexArray(VAOId);
// Step2: 创建并绑定VBO 对象
glGenBuffers(1, &VBOId);
glBindBuffer(GL_ARRAY_BUFFER, VBOId);
GLuint TempBufferId;
glGenBuffers(1, &TempBufferId);
glBindBuffer(GL_COPY_WRITE_BUFFER, TempBufferId);
// Step3: 映射数据到GL_COPY_WRITE_BUFFER
glBufferData(GL_COPY_WRITE_BUFFER, sizeof(vertices), NULL, GL_STATIC_DRAW); // 预分配空间
void* ptr = glMapBuffer(GL_COPY_WRITE_BUFFER, GL_WRITE_ONLY);
if (!ptr)
{
std::cerr << " map buffer failed!" << std::endl;
return;
}
memcpy(ptr, vertices, sizeof(vertices)); // 可以操作这个指针指向的内存空间
glUnmapBuffer(GL_COPY_WRITE_BUFFER);
// Step4: 将数据拷贝到VBO
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), NULL, GL_STATIC_DRAW); // 注意拷贝前预分配空间
glCopyBufferSubData(GL_COPY_WRITE_BUFFER, GL_ARRAY_BUFFER, 0, 0, sizeof(vertices));
glDeleteBuffers(1, &TempBufferId);
// Step5: 指定解析方式 并启用顶点属性
// 顶点位置属性
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GL_FLOAT), (GLvoid*)0);
glEnableVertexAttribArray(0);
// 顶点颜色属性
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE,
8 * sizeof(GL_FLOAT), (GLvoid*)(3 * sizeof(GL_FLOAT)));
glEnableVertexAttribArray(1);
// 顶点纹理坐标
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE,
8 * sizeof(GL_FLOAT), (GLvoid*)(6 * sizeof(GL_FLOAT)));
glEnableVertexAttribArray(2);
glBindBuffer(GL_COPY_WRITE_BUFFER, 0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
VBOIdVec.push_back(VBOId);
}
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