cqopengldisplay.cpp

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

CQOpenGLDisplay::CQOpenGLDisplay(QWidget *disParent):QOpenGLWidget(disParent)
{
    textureUniformY = 0;
    textureUniformU = 0;
    textureUniformV = 0;

    id_y = 0;
    id_u = 0;
    id_v = 0;

    m_pVSHader = NULL;
    m_pFSHader = NULL;
    m_pShaderProgram = NULL;

    m_pTextureY = NULL;
    m_pTextureU = NULL;
    m_pTextureV = NULL;

    m_nVideoH = 0;
    m_nVideoW = 0;

    paintFlag = false;
}
CQOpenGLDisplay::~CQOpenGLDisplay()
{
    if (m_pVSHader)
    {
        delete(m_pVSHader);
    }
    if (m_pFSHader)
    {
        delete(m_pFSHader);
    }

    if (m_pShaderProgram)
    {
        delete(m_pShaderProgram);
    }

    if (m_pTextureY)
    {
        delete(m_pTextureY);
    }
    if (m_pTextureU)
    {
        delete(m_pTextureU);
    }
    if (m_pTextureV)
    {
        delete(m_pTextureV);
    }
}
void CQOpenGLDisplay::openGLVideoPlayer(uchar * y_data,uchar *u_data, uchar *v_data,int width,int height)
{
    m_pBufYuv[0] = y_data;//Y
    m_pBufYuv[1] = u_data;//U
    m_pBufYuv[2] = v_data;//V

    m_nVideoW = width;
    m_nVideoH = height;

    //刷新界面,触发paintGL接口
    update();
}
void CQOpenGLDisplay::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);
    //顶点着色器源码
    const char *vsrc = "attribute vec4 vertexIn; \
    attribute vec2 textureIn; \
    varying vec2 textureOut;  \
    void main(void)           \
    {                         \
        gl_Position = vertexIn; \
        textureOut = textureIn; \
    }";
    //编译顶点着色器程序
    bool bCompile = m_pVSHader->compileSourceCode(vsrc);
    if(!bCompile)
    {
    }

    //初始化片段着色器 功能gpu中yuv转换成rgb
    m_pFSHader = new QOpenGLShader(QOpenGLShader::Fragment, this);
    //片段着色器源码
    const char *fsrc = "varying highp vec2 textureOut; \
    uniform sampler2D tex_y; \
    uniform sampler2D tex_u; \
    uniform sampler2D tex_v; \
    void main(void) \
    { \
        highp vec3 yuv; \
        highp 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); \
    }";
    //将glsl源码送入编译器编译着色器程序
    bCompile = m_pFSHader->compileSourceCode(fsrc);
    if(!bCompile)
    {
    }
#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();
    //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();

    m_pTextureY->setMagnificationFilter(QOpenGLTexture::Linear);
    m_pTextureY->setMinificationFilter(QOpenGLTexture::Linear);
    m_pTextureY->setWrapMode(QOpenGLTexture::ClampToEdge);

    m_pTextureU->setMagnificationFilter(QOpenGLTexture::Linear);
    m_pTextureU->setMinificationFilter(QOpenGLTexture::Linear);
    m_pTextureU->setWrapMode(QOpenGLTexture::ClampToEdge);

    m_pTextureV->setMagnificationFilter(QOpenGLTexture::Linear);
    m_pTextureV->setMinificationFilter(QOpenGLTexture::Linear);
    m_pTextureV->setWrapMode(QOpenGLTexture::ClampToEdge);

    //glClearColor(static_cast<GLclampf>(0.15),static_cast<GLclampf>(0.27),static_cast<GLclampf>(0.35),static_cast<GLclampf>(0.5));//设置背景色80264558
    //qDebug("addr=%x id_y = %d id_u=%d id_v=%d\n", this, id_y, id_u, id_v);
    glClearColor(static_cast<GLclampf>(1.0),static_cast<GLclampf>(1.0),static_cast<GLclampf>(1.0),static_cast<GLclampf>(1.0));
}
void CQOpenGLDisplay::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 CQOpenGLDisplay::paintGL()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    //加载y数据纹理
    glActiveTexture(GL_TEXTURE0);//激活纹理单元GL_TEXTURE0
    //使用来自y数据生成纹理
    m_pTextureY->bind();
    //使用内存中m_pBufYuv数据创建真正的y数据纹理
    glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, m_nVideoW, m_nVideoH, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, m_pBufYuv[0]);

    //加载u数据纹理
    glActiveTexture(GL_TEXTURE1);//激活纹理单元GL_TEXTURE1
    m_pTextureU->bind();
    glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, m_nVideoW/2, m_nVideoH/2, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, m_pBufYuv[1]);

    //加载v数据纹理
    glActiveTexture(GL_TEXTURE2);//激活纹理单元GL_TEXTURE2
    m_pTextureV->bind();
    glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, m_nVideoW/2, m_nVideoH/2, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, m_pBufYuv[2]);

    //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GL_TEXTURE2
    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);
    //使用顶点数组方式绘制图形
    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
    paintFlag = true;
    //return;
 }