PreviewWidget Class Reference

#include <previewWidget.hpp>

Inheritance diagram for PreviewWidget:

Collaboration diagram for PreviewWidget:

Public Member Functions
	PreviewWidget (QWidget *parent)
	~PreviewWidget ()
void	setKey (std::string_view key)
void	start ()
void	stop ()

Protected Member Functions
void	initializeGL ()
void	paintGL ()
void	resizeGL (int w, int h)

Private Member Functions
void	calculateScale ()
bool	loadFrame ()
void	render ()
void	setVidSize (int w, int h)

Private Attributes
GLuint	frame_texture = 0
int	height = 0
Ipc_frame_uniq	ipc_frame
Ipc_frame_reader_uniq	ipc_frame_reader
GLuint	program = 0
GLfloat	scaleVec [2]
GLuint	selected_texture = 0
GLuint	testbars_texture = 0
QTimer	timer
QOpenGLVertexArrayObject	vao
GLuint	vertexBuffer = 0
int	vidH = 0
int	vidW = 0
int	width = 0

Detailed Description

Definition at line 14 of file previewWidget.hpp.

Constructor & Destructor Documentation

PreviewWidget()

PreviewWidget::PreviewWidget

(

QWidget *

parent

)

Definition at line 81 of file previewWidget.cpp.

                                            :
        QOpenGLWidget(parent),
        ipc_frame(ipc_frame_new())
{
        connect(&timer, SIGNAL(timeout()), this, SLOT(update()));
}

References timer.

~PreviewWidget()

PreviewWidget::~PreviewWidget

(

)

Definition at line 88 of file previewWidget.cpp.

                             {
        makeCurrent();
 
        auto f = getOpenGLFuncs();
        f->glDeleteBuffers(1, &vertexBuffer);
        f->glDeleteProgram(program);
        f->glDeleteTextures(1, &frame_texture);
        f->glDeleteTextures(1, &testbars_texture);
        vao.destroy();
        doneCurrent();
}

References frame_texture, getOpenGLFuncs(), program, testbars_texture, vao, and vertexBuffer.

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Member Function Documentation

calculateScale()

void PreviewWidget::calculateScale ( )

private

Definition at line 186 of file previewWidget.cpp.

                                  {
        double videoAspect = (double) vidW / vidH;
        double widgetAspect = (double) width / height;
 
        if(videoAspect > widgetAspect){
                float scale = widgetAspect / videoAspect;
                scaleVec[0] = 1;
                scaleVec[1] = scale;
        } else {
                float scale = videoAspect / widgetAspect;
                scaleVec[0] = scale;
                scaleVec[1] = 1;
        }
}

References height, scaleVec, vidH, vidW, and width.

Referenced by resizeGL(), and setVidSize().

initializeGL()

void PreviewWidget::initializeGL ( )

protected

Definition at line 100 of file previewWidget.cpp.

                                {
        auto f = getOpenGLFuncs();
 
        if(!f) {
                QMessageBox warningBox(this);
                warningBox.setText("OpenGL 3.3 is required!");
                warningBox.exec();
                exit(1);
        }
 
        vao.create();
        vao.bind();
 
        f->glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
 
        f->glDisable(GL_DEPTH_TEST);
        f->glDisable(GL_SCISSOR_TEST);
        f->glDisable(GL_STENCIL_TEST);
 
        GLuint vertexShader = f->glCreateShader(GL_VERTEX_SHADER);
        GLuint fragShader = f->glCreateShader(GL_FRAGMENT_SHADER);
 
        f->glShaderSource(vertexShader, 1, &vert_src, NULL);
        compileShader(vertexShader, f);
        f->glShaderSource(fragShader, 1, &frag_src, NULL);
        compileShader(fragShader, f);
 
        program = f->glCreateProgram();
        f->glAttachShader(program, vertexShader);
        f->glAttachShader(program, fragShader);
        f->glLinkProgram(program);
        f->glUseProgram(program);
 
        f->glDetachShader(program, vertexShader);
        f->glDetachShader(program, fragShader);
        f->glDeleteShader(vertexShader);
        f->glDeleteShader(fragShader);
 
        f->glGenTextures(1, &testbars_texture);
        f->glBindTexture(GL_TEXTURE_2D, testbars_texture);
        f->glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 4, 4, 0, GL_RGB, GL_UNSIGNED_BYTE, pixels);
        f->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        f->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 
        f->glGenTextures(1, &frame_texture);
        f->glBindTexture(GL_TEXTURE_2D, frame_texture);
        f->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        f->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        f->glPixelStorei(GL_UNPACK_ALIGNMENT, 1); //UltraGrid formats dont have padding between rows
 
        f->glBindTexture(GL_TEXTURE_2D, 0);
 
        f->glGenBuffers(1, &vertexBuffer);
        f->glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
        f->glBufferData(GL_ARRAY_BUFFER, sizeof(rectangle), rectangle, GL_STATIC_DRAW);
 
        f->glEnableVertexAttribArray(0);
        f->glVertexAttribPointer(
                        0,
                        2,
                        GL_FLOAT,
                        GL_FALSE,
                        4 * sizeof(float),
                        (void*)0
                        );
        f->glEnableVertexAttribArray(1);
        f->glVertexAttribPointer(
                        1,
                        2,
                        GL_FLOAT,
                        GL_FALSE,
                        4 * sizeof(float),
                        (void*)(2 * sizeof(float))
                        );
 
        f->glBindBuffer(GL_ARRAY_BUFFER, 0);
 
        vao.release();
 
        scaleVec[0] = 0.75f;
        scaleVec[1] = 0.5;
 
        vidW = 1280;
        vidH = 720;
}

References compileShader(), frag_src, frame_texture, getOpenGLFuncs(), pixels, program, rectangle, scaleVec, testbars_texture, vao, vert_src, vertexBuffer, vidH, and vidW.

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loadFrame()

bool PreviewWidget::loadFrame ( )

private

Definition at line 217 of file previewWidget.cpp.

                             {
        auto f = getOpenGLFuncs();
 
        if(!ipc_frame_reader || !ipc_frame_reader_is_connected(ipc_frame_reader.get())){
                selected_texture = testbars_texture;
                return true;
        }
 
 
        if(ipc_frame_reader_has_frame(ipc_frame_reader.get())){
                if(!ipc_frame_reader_read(ipc_frame_reader.get(), ipc_frame.get()))
                        return false;
 
                assert(ipc_frame->header.color_spec == IPC_FRAME_COLOR_RGB);
                selected_texture = frame_texture;
                f->glBindTexture(GL_TEXTURE_2D, frame_texture);
                f->glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB,
                                ipc_frame->header.width, ipc_frame->header.height,
                                0, GL_RGB, GL_UNSIGNED_BYTE, ipc_frame->data);
                setVidSize(ipc_frame->header.width, ipc_frame->header.height);
        }
 
        return true;
}

References frame_texture, getOpenGLFuncs(), ipc_frame, IPC_FRAME_COLOR_RGB, ipc_frame_reader, ipc_frame_reader_has_frame(), ipc_frame_reader_is_connected(), ipc_frame_reader_read(), selected_texture, setVidSize(), and testbars_texture.

Referenced by paintGL().

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paintGL()

void PreviewWidget::paintGL ( )

protected

Definition at line 260 of file previewWidget.cpp.

                           {
        loadFrame();
        render();
}

References loadFrame(), and render().

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render()

void PreviewWidget::render ( )

private

Definition at line 242 of file previewWidget.cpp.

                          {
        auto f = getOpenGLFuncs();
 
        vao.bind();
        f->glClear(GL_COLOR_BUFFER_BIT);
 
        f->glUseProgram(program);
 
        f->glBindTexture(GL_TEXTURE_2D, selected_texture);
        GLuint loc;
        loc = f->glGetUniformLocation(program, "scale_vec");
        f->glUniform2fv(loc, 1, scaleVec);
 
        f->glDrawArrays(GL_TRIANGLES, 0, 6);
 
        vao.release();
}

References getOpenGLFuncs(), program, scaleVec, selected_texture, and vao.

Referenced by paintGL().

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resizeGL()

void PreviewWidget::resizeGL ( int w, int h )

protected

Definition at line 201 of file previewWidget.cpp.

                                        {
        width = w;
        height = h;
 
        calculateScale();
}

References calculateScale(), height, and width.

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setKey()

void PreviewWidget::setKey

(

std::string_view

key

)

Definition at line 286 of file previewWidget.cpp.

                                            {
        std::string path = get_temp_dir();
        path += key;
        ipc_frame_reader.reset(ipc_frame_reader_new(path.c_str()));
}

References get_temp_dir(), ipc_frame_reader, ipc_frame_reader_new(), and key.

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setVidSize()

void PreviewWidget::setVidSize ( int w, int h )

private

Definition at line 208 of file previewWidget.cpp.

                                          {
        if(vidW == w && vidH == h)
                return;
 
        vidW = w;
        vidH = h;
        calculateScale();
}

References calculateScale(), vidH, and vidW.

Referenced by loadFrame().

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start()

void PreviewWidget::start

(

)

Definition at line 292 of file previewWidget.cpp.

                         {
        timer.start(1000/24);
}

References timer.

stop()

void PreviewWidget::stop

(

)

Definition at line 296 of file previewWidget.cpp.

                        {
        timer.stop();
}

References timer.

Member Data Documentation

frame_texture

GLuint PreviewWidget::frame_texture = 0

private

Definition at line 34 of file previewWidget.hpp.

Referenced by ~PreviewWidget(), initializeGL(), and loadFrame().

height

int PreviewWidget::height = 0

private

Definition at line 45 of file previewWidget.hpp.

Referenced by calculateScale(), and resizeGL().

ipc_frame

Ipc_frame_uniq PreviewWidget::ipc_frame

private

Definition at line 50 of file previewWidget.hpp.

Referenced by loadFrame().

ipc_frame_reader

Ipc_frame_reader_uniq PreviewWidget::ipc_frame_reader

private

Definition at line 51 of file previewWidget.hpp.

Referenced by loadFrame(), and setKey().

program

GLuint PreviewWidget::program = 0

private

Definition at line 33 of file previewWidget.hpp.

Referenced by ~PreviewWidget(), initializeGL(), and render().

scaleVec

GLfloat PreviewWidget::scaleVec[2]

private

Definition at line 41 of file previewWidget.hpp.

Referenced by calculateScale(), initializeGL(), and render().

selected_texture

GLuint PreviewWidget::selected_texture = 0

private

Definition at line 37 of file previewWidget.hpp.

Referenced by loadFrame(), and render().

testbars_texture

GLuint PreviewWidget::testbars_texture = 0

private

Definition at line 35 of file previewWidget.hpp.

Referenced by ~PreviewWidget(), initializeGL(), and loadFrame().

timer

QTimer PreviewWidget::timer

private

Definition at line 52 of file previewWidget.hpp.

Referenced by PreviewWidget(), start(), and stop().

vao

QOpenGLVertexArrayObject PreviewWidget::vao

private

Definition at line 39 of file previewWidget.hpp.

Referenced by ~PreviewWidget(), initializeGL(), and render().

vertexBuffer

GLuint PreviewWidget::vertexBuffer = 0

private

Definition at line 32 of file previewWidget.hpp.

Referenced by ~PreviewWidget(), and initializeGL().

vidH

int PreviewWidget::vidH = 0

private

Definition at line 43 of file previewWidget.hpp.

Referenced by calculateScale(), initializeGL(), and setVidSize().

vidW

int PreviewWidget::vidW = 0

private

Definition at line 42 of file previewWidget.hpp.

Referenced by calculateScale(), initializeGL(), and setVidSize().

width

int PreviewWidget::width = 0

private

Definition at line 44 of file previewWidget.hpp.

Referenced by calculateScale(), and resizeGL().

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The documentation for this class was generated from the following files:

• gui/QT/widget/previewWidget.hpp
• gui/QT/widget/previewWidget.cpp