#include <QOpenGLTexture>
#include <QOpenGLBuffer>
#include <QMouseEvent>
#include "CPlayWidget.h"


// 顶点着色器源码
const char *vsrcyuv = "attribute vec4 vertexIn; \
attribute vec2 textureIn; \
varying vec2 textureOut;  \
void main(void)           \
{                         \
    gl_Position = vertexIn; \
    textureOut = textureIn; \
}";
// 片段着色器源码
const char *fsrcyuv = "varying vec2 textureOut; \
uniform sampler2D tex_y; \
uniform sampler2D tex_u; \
uniform sampler2D tex_v; \
void main(void) \
{ \
    vec3 yuv; \
    vec3 rgb; \
    yuv.x = texture2D(tex_y, textureOut).r; \
    yuv.y = texture2D(tex_u, textureOut).r - 0.5; \
    yuv.z = texture2D(tex_v, textureOut).r - 0.5; \
    rgb = mat3( 1,       1,         1, \
                0,       -0.39465,  2.03211, \
                1.13983, -0.58060,  0) * yuv; \
    gl_FragColor = vec4(rgb, 1); \
}";
// rgb片段着色器源码
// 注意MEDIASUBTYPE_RGB32 是bgr的，所以需要再进行一次转换
const char *fsrcrgb = "varying vec2 textureOut;  \
        uniform sampler2D rgbdata; \
        void main() \
        { \
            gl_FragColor = texture(rgbdata, textureOut);  \
        }";

void CPlayWidget::OnUpdateFrame() {
    this->PlayOneFrame();
}

void CPlayWidget::OnPaintData(const uint8_t *data, uint32_t len)
{
    if(nullptr == m_pBufYuv420p)
    {
        m_pBufYuv420p = new unsigned char[len];
        qDebug("CPlayWidget::PlayOneFrame new data memory. Len=%d width=%d height=%d\n",
               len, m_nVideoW, m_nVideoW);
        memcpy(m_pBufYuv420p, data,len);
        //刷新界面,触发paintGL接口
        update();
    }
}

CPlayWidget::CPlayWidget(QWidget *parent):QOpenGLWidget(parent) {
    textureUniformY = 0;
    textureUniformU = 0;
    textureUniformV = 0;
    id_y = 0;
    id_u = 0;
    id_v = 0;
    m_pTextureRGB = nullptr;
    m_pBufYuv420p = NULL;
    m_pVSHader = NULL;
    m_pFSHader = NULL;
    m_pShaderProgram = NULL;
    m_pTextureY = NULL;
    m_pTextureU = NULL;
    m_pTextureV = NULL;
    m_pYuvFile = NULL;
    m_nVideoH = 0;
    m_nVideoW = 0;
    mType = TYPE_YUV420P;
    connect(&this->tm,SIGNAL(timeout()),this,SLOT(OnUpdateFrame()));
    //tm.start(1000);
}

CPlayWidget::~CPlayWidget() {
}

void CPlayWidget::PlayOneFrame() {//函数功能读取一张yuv图像数据进行显示,每单击一次，就显示一张图片
    if(NULL == m_pYuvFile)
    {
        //打开yuv视频文件 注意修改文件路径
       // m_pYuvFile = fopen("F://OpenglYuvDemo//1920_1080.yuv", "rb");
         m_pYuvFile = fopen("F://md_sample_sp420_1080p.yuv", "rb");
        //根据yuv视频数据的分辨率设置宽高,demo当中是1080p，这个地方要注意跟实际数据分辨率对应上
//        m_nVideoW = 1920;
//        m_nVideoH = 1080;
    }
    //申请内存存一帧yuv图像数据,其大小为分辨率的1.5倍
    int nLen = m_nVideoW*m_nVideoH*3/2;
    if(nullptr == m_pBufYuv420p)
    {
        m_pBufYuv420p = new unsigned char[nLen];
        qDebug("CPlayWidget::PlayOneFrame new data memory. Len=%d width=%d height=%d\n",
               nLen, m_nVideoW, m_nVideoW);
    }
    //将一帧yuv图像读到内存中
    if(NULL == m_pYuvFile)
    {
        qFatal("read yuv file err.may be path is wrong!\n");
        return;
    }
    fread(m_pBufYuv420p, 1, nLen, m_pYuvFile);
    //刷新界面,触发paintGL接口
    update();
    return;
}

int CPlayWidget::SetDataType(CPlayWidget::IMG_TYPE type){
    this->mType = type;
}

int CPlayWidget::OnCameraData(uint8_t *dat, uint32_t size)
{
    memcpy(this->m_pBufRgb32,dat,size);
    update();
}

int CPlayWidget::SetImgSize(uint32_t width, uint32_t height)
{
    m_nVideoH = height;
    m_nVideoW = width;
    if(mType == TYPE_RGB32){
        m_pBufRgb32 = new uint8_t[width * height *4];
    }
    if(mType == TYPE_YUV420P){
        m_pBufYuv420p = new uint8_t[width * height *3/2];
    }
}


/*

 * Y = 0.299 R + 0.587 G + 0.114 B

U = - 0.1687 R - 0.3313 G + 0.5 B + 128

V = 0.5 R - 0.4187 G - 0.0813 B + 128

反过来，RGB 也可以直接从YUV (256级别) 计算:

R = Y + 1.402 (Cr-128)

G = Y - 0.34414 (Cb-128) - 0.71414 (Cr-128)

B = Y + 1.772 (Cb-128)
*/
void CPlayWidget::initializeGL()
{
    initializeOpenGLFunctions();
    glEnable(GL_DEPTH_TEST);
    //现代opengl渲染管线依赖着色器来处理传入的数据
    //着色器：就是使用openGL着色语言(OpenGL Shading Language, GLSL)编写的一个小函数,
    //       GLSL是构成所有OpenGL着色器的语言,具体的GLSL语言的语法需要读者查找相关资料
    //初始化顶点着色器 对象
    m_pVSHader = new QOpenGLShader(QOpenGLShader::Vertex, this);

    //编译顶点着色器程序
    bool bCompile = m_pVSHader->compileSourceCode(vsrcyuv);
    if(!bCompile)
    {
        // todo 设置错误状态
    }
    //初始化片段着色器 功能gpu中yuv转换成rgb
    m_pFSHader = new QOpenGLShader(QOpenGLShader::Fragment, this);
    if(mType == TYPE_RGB32){
        bCompile = m_pFSHader->compileSourceCode(fsrcrgb);
    }
    if(mType == TYPE_YUV420P){
        bCompile = m_pFSHader->compileSourceCode(fsrcyuv);
    }
    if(!bCompile)
    {
        // todo 设置错误状态
    }
#define PROGRAM_VERTEX_ATTRIBUTE 0
#define PROGRAM_TEXCOORD_ATTRIBUTE 1
    //创建着色器程序容器
    m_pShaderProgram = new QOpenGLShaderProgram;
    //将片段着色器添加到程序容器
    m_pShaderProgram->addShader(m_pFSHader);
    //将顶点着色器添加到程序容器
    m_pShaderProgram->addShader(m_pVSHader);
    //绑定属性vertexIn到指定位置ATTRIB_VERTEX,该属性在顶点着色源码其中有声明
    m_pShaderProgram->bindAttributeLocation("vertexIn", ATTRIB_VERTEX);
    //绑定属性textureIn到指定位置ATTRIB_TEXTURE,该属性在顶点着色源码其中有声明
    m_pShaderProgram->bindAttributeLocation("textureIn", ATTRIB_TEXTURE);
    //链接所有所有添入到的着色器程序
    m_pShaderProgram->link();
    //激活所有链接
    m_pShaderProgram->bind();

    if(this->mType == TYPE_YUV420P){
        initShaderYuv();
    }
    if(this->mType == TYPE_RGB32){
        initShaderRgb();
    }
    glClearColor(0.0,0.0,0.0,0.0);//设置背景色
}
void CPlayWidget::resizeGL(int w, int h)
{
    if(h == 0)// 防止被零除
    {
        h = 1;// 将高设为1
    }
    //设置视口
    glViewport(0,0, w,h);
}
 void CPlayWidget::paintGL()
 {
     if(mType == TYPE_YUV420P)
        loadYuvTexture();
     if(mType == TYPE_RGB32){
         loadRgbTexture();
     }
    //使用顶点数组方式绘制图形
    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
    return;
 }

 void CPlayWidget::initShaderYuv()
 {
     //读取着色器中的数据变量tex_y, tex_u, tex_v的位置,这些变量的声明可以在
     //片段着色器源码中可以看到
     textureUniformY = m_pShaderProgram->uniformLocation("tex_y");
     textureUniformU =  m_pShaderProgram->uniformLocation("tex_u");
     textureUniformV =  m_pShaderProgram->uniformLocation("tex_v");
     // 顶点矩阵
     static const GLfloat vertexVertices[] = {
         -1.0f, -1.0f,
          1.0f, -1.0f,
          -1.0f, 1.0f,
          1.0f, 1.0f,
     };
     //纹理矩阵
     static const GLfloat textureVertices[] = {
         0.0f,  1.0f,
         1.0f,  1.0f,
         0.0f,  0.0f,
         1.0f,  0.0f,
     };
     //设置属性ATTRIB_VERTEX的顶点矩阵值以及格式
     glVertexAttribPointer(ATTRIB_VERTEX, 2, GL_FLOAT, 0, 0, vertexVertices);
     //设置属性ATTRIB_TEXTURE的纹理矩阵值以及格式
     glVertexAttribPointer(ATTRIB_TEXTURE, 2, GL_FLOAT, 0, 0, textureVertices);
     //启用ATTRIB_VERTEX属性的数据,默认是关闭的
     glEnableVertexAttribArray(ATTRIB_VERTEX);
     //启用ATTRIB_TEXTURE属性的数据,默认是关闭的
     glEnableVertexAttribArray(ATTRIB_TEXTURE);
     //分别创建y,u,v纹理对象
     m_pTextureY = new QOpenGLTexture(QOpenGLTexture::Target2D);
     m_pTextureU = new QOpenGLTexture(QOpenGLTexture::Target2D);
     m_pTextureV = new QOpenGLTexture(QOpenGLTexture::Target2D);
     m_pTextureY->create();
     m_pTextureU->create();
     m_pTextureV->create();
     //获取返回y分量的纹理索引值
     id_y = m_pTextureY->textureId();
     //获取返回u分量的纹理索引值
     id_u = m_pTextureU->textureId();
     //获取返回v分量的纹理索引值
     id_v = m_pTextureV->textureId();
 }

 void CPlayWidget::initShaderRgb()
 {
     //读取着色器中的数据变量tex_y, tex_u, tex_v的位置,这些变量的声明可以在
     //片段着色器源码中可以看到
     textureUniformRGB = m_pShaderProgram->uniformLocation("rgbdata");
     // 顶点矩阵
     static const GLfloat vertexVertices[] = {
        -1.0f, -1.0f,
        1.0f, -1.0f,
        -1.0f, 1.0f,
        1.0f, 1.0f,
        };
     //纹理矩阵
     static const GLfloat textureVertices[] = {
        0.0f,  0.0f,
        1.0f,  0.0f,
        0.0f,  1.0f,
        1.0f,  1.0f,
     };
     //设置属性ATTRIB_VERTEX的顶点矩阵值以及格式
     glVertexAttribPointer(ATTRIB_VERTEX, 2, GL_FLOAT, 0, 0, vertexVertices);
     //设置属性ATTRIB_TEXTURE的纹理矩阵值以及格式
     glVertexAttribPointer(ATTRIB_TEXTURE, 2, GL_FLOAT, 0, 0, textureVertices);
     //启用ATTRIB_VERTEX属性的数据,默认是关闭的
     glEnableVertexAttribArray(ATTRIB_VERTEX);
     //启用ATTRIB_TEXTURE属性的数据,默认是关闭的
     glEnableVertexAttribArray(ATTRIB_TEXTURE);
     //分别创建y,u,v纹理对象
     m_pTextureRGB = new QOpenGLTexture(QOpenGLTexture::Target2D);
     m_pTextureRGB->create();
     //获取返回y分量的纹理索引值
     id_rgb = m_pTextureRGB->textureId();
 }

 int CPlayWidget::loadYuvTexture()
 {
     //加载y数据纹理
      //激活纹理单元GL_TEXTURE0
     glActiveTexture(GL_TEXTURE0);
     //使用来自y数据生成纹理
     glBindTexture(GL_TEXTURE_2D, id_y);
     //使用内存中m_pBufYuv420p数据创建真正的y数据纹理
     glTexImage2D(GL_TEXTURE_2D,
                  0,
                  GL_RED,
                  m_nVideoW,
                  m_nVideoH,
                  0,
                  GL_RED,
                  GL_UNSIGNED_BYTE,
                  m_pBufYuv420p);
     glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
     //加载u数据纹理
     glActiveTexture(GL_TEXTURE1);//激活纹理单元GL_TEXTURE1
     glBindTexture(GL_TEXTURE_2D, id_u);
     glTexImage2D(GL_TEXTURE_2D,
                  0, GL_RED,
                  m_nVideoW/2,
                  m_nVideoH/2,
                  0,
                  GL_RED,
                  GL_UNSIGNED_BYTE,
                  (char*)m_pBufYuv420p+m_nVideoW*m_nVideoH);
     glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
     //加载v数据纹理
     glActiveTexture(GL_TEXTURE2);//激活纹理单元GL_TEXTURE2
     glBindTexture(GL_TEXTURE_2D, id_v);
     glTexImage2D(GL_TEXTURE_2D,
                  0, GL_RED,
                  m_nVideoW/2,
                  m_nVideoH/2,
                  0, GL_RED,
                  GL_UNSIGNED_BYTE,
                  (char*)m_pBufYuv420p+m_nVideoW*m_nVideoH*5/4);
     glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
     //指定y纹理要使用新值 只能用0,1,2等表示纹理单元的索引，这是opengl不人性化的地方
     //0对应纹理单元GL_TEXTURE0 1对应纹理单元GL_TEXTURE1 2对应纹理的单元
     glUniform1i(textureUniformY, 0);
     //指定u纹理要使用新值
     glUniform1i(textureUniformU, 1);
     //指定v纹理要使用新值
     glUniform1i(textureUniformV, 2);
     return 0;
 }

 int CPlayWidget::loadRgbTexture()
 {
     //加载rgb数据纹理
      //激活纹理单元GL_TEXTURE0
     glActiveTexture(GL_TEXTURE0);
     //使用来自y数据生成纹理
     glBindTexture(GL_TEXTURE_2D, id_rgb);
     //使用内存中m_pBufYuv420p数据创建真正的y数据纹理
     glTexImage2D(GL_TEXTURE_2D,
                  0,
                  GL_RGBA,
                  m_nVideoW,
                  m_nVideoH,
                  0,
                  GL_BGRA,
                  GL_UNSIGNED_BYTE,
                  m_pBufRgb32);
     glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
     glUniform1i(textureUniformRGB, 0);
 }