I'm experiencing a very unexpected problem with OpenGL rendering on QML items. I'm loading images from 4 live cameras. Turns out that the 4th camera is faulty, and gives no image. When this happens, this camera assumes the image of another camera, for no reason at all even though they are completely separate objects! You can see that the 4th object in the grid repeats the first image.
All I'm doing is instantiating a class through main.qml:
import QtQuick 2.0
import OpenGlMaterialQQuickItem 1.0
Grid {
columns: 2
spacing: 0
width: 1280
height: 720
OpenGlMaterialQQuickItem {
width: 640
height: 360
uri: "rtsp://admin:123456@192.168.1.178:10554/tcp/av0_0"
}
OpenGlMaterialQQuickItem {
width: 640
height: 360
uri: "rtsp://admin:123456@192.168.1.198:10554/tcp/av0_0"
}
OpenGlMaterialQQuickItem {
width: 640
height: 360
uri: "rtsp://admin:123456@192.168.1.72:10554/tcp/av0_0"
}
OpenGlMaterialQQuickItem {
width: 640
height: 360
uri: "rtsp://admin:123456@192.168.1.155:10554/tcp/av0_0"
}
}
Here's the OpenGlMaterialQQuickItem class:
#include "OpenGlMaterialQQuickItem.h"
//https://github.com/KDE/plasma-framework/blob/e7329b95ed3e654e7b5edb4cf7c044b91f8d4d0a/src/declarativeimports/core/fadingnode.cpp
#define GET_STR(x) #x
#define VERTEX_ATTRIBUTE 3
struct State
{
public://TEMPORARY
int frameWidth = 1920;
int frameHeight = 1080;
unsigned char *datas[3] = {0};
private:
bool firstRender = true;
public:
void updateData(unsigned char**data, int frameWidth, int frameHeight)
{
this->frameWidth = frameWidth;
this->frameHeight = frameHeight;
if (firstRender) {
datas[0] = new unsigned char[frameWidth*frameHeight]; //Y
datas[1] = new unsigned char[frameWidth*frameHeight/4];//U
datas[2] = new unsigned char[frameWidth*frameHeight/4];//V
firstRender = false;
}
memcpy(datas[0], data[0], frameWidth*frameHeight);
memcpy(datas[1], data[1], frameWidth*frameHeight/4);
memcpy(datas[2], data[2], frameWidth*frameHeight/4);
}
int compare(const State *other) const {
std::cout << "compare called " << std::endl;
/*
uint rgb = color.rgba();
uint otherRgb = other->color.rgba();
if (rgb == otherRgb) {
return 0;
} else if (rgb < otherRgb) {
return -1;
} else {
return 1;
}
*/
return -1;
}
};
class Shader : public QSGSimpleMaterialShader<State>
{
//QSG_DECLARE_SIMPLE_COMPARABLE_SHADER(Shader, State);
QSG_DECLARE_SIMPLE_SHADER(Shader, State);
private:
QOpenGLFunctions *glFuncs = nullptr;
GLuint unis[3] = {0};
GLuint texs[3] = {0};
QSize m_viewportSize;
bool firstRender = true;
public:
const char *vertexShader() const override {
return GET_STR(
uniform highp mat4 qt_Matrix;
attribute vec4 vertexIn;
attribute vec2 textureIn;
varying vec2 textureOut;
void main(void)
{
gl_Position = qt_Matrix * vertexIn;
textureOut = textureIn;
}
);
}
const char *fragmentShader() const override {
return GET_STR(
varying vec2 textureOut;
uniform sampler2D tex_y;
uniform sampler2D tex_u;
uniform sampler2D tex_v;
uniform lowp float qt_Opacity;
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(1.0, 1.0, 1.0,
0.0, -0.39465, 2.03211,
1.13983, -0.58060, 0.0) * yuv;
gl_FragColor = vec4(rgb, 1.0) * qt_Opacity;
}
);
}
QList<QByteArray> attributes() const override
{
return {QByteArrayLiteral("vertexIn"), QByteArrayLiteral("textureIn")};
}
void initialize()
{
if (!program()->isLinked()) {
return; //shader not linked, exit otherwise we crash, BUG: 336272
}
QSGSimpleMaterialShader<State>::initialize();
glFuncs = QOpenGLContext::currentContext()->functions();
program()->bind();
glFuncs->glGenTextures(3, texs);//TODO: delete these textures on exit
}
void updateState(const State *state, const State *) override
{
//Y
glFuncs->glBindTexture(GL_TEXTURE_2D, texs[0]);
glFuncs->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glFuncs->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glFuncs->glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, state->frameWidth, state->frameHeight, 0, GL_RED, GL_UNSIGNED_BYTE, 0);
//U
glFuncs->glBindTexture(GL_TEXTURE_2D, texs[1]);
glFuncs->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glFuncs->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glFuncs->glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, state->frameWidth/2, state->frameHeight / 2, 0, GL_RED, GL_UNSIGNED_BYTE, 0);
//V
glFuncs->glBindTexture(GL_TEXTURE_2D, texs[2]);
glFuncs->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glFuncs->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glFuncs->glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, state->frameWidth / 2, state->frameHeight / 2, 0, GL_RED, GL_UNSIGNED_BYTE, 0);
glFuncs->glActiveTexture(GL_TEXTURE0);
glFuncs->glBindTexture(GL_TEXTURE_2D, texs[0]);
glFuncs->glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, state->frameWidth, state->frameHeight, GL_RED, GL_UNSIGNED_BYTE, state->datas[0]);
glFuncs->glUniform1i(unis[0], 0);
glFuncs->glActiveTexture(GL_TEXTURE0+1);
glFuncs->glBindTexture(GL_TEXTURE_2D, texs[1]);
glFuncs->glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, state->frameWidth/2, state->frameHeight / 2, GL_RED, GL_UNSIGNED_BYTE, state->datas[1]);
glFuncs->glUniform1i(unis[1],1);
glFuncs->glActiveTexture(GL_TEXTURE0+2);
glFuncs->glBindTexture(GL_TEXTURE_2D, texs[2]);
glFuncs->glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, state->frameWidth / 2, state->frameHeight / 2, GL_RED, GL_UNSIGNED_BYTE, state->datas[2]);
glFuncs->glUniform1i(unis[2], 2);
glFuncs->glDrawArrays(GL_TRIANGLE_STRIP,0,4);
//release some things here?
}
void resolveUniforms() override
{
unis[0] = program()->uniformLocation("tex_y");
unis[1] = program()->uniformLocation("tex_u");
unis[2] = program()->uniformLocation("tex_v");
}
};
class Node: public QSGGeometryNode, public FrameUpdater
{
public:
State state;
Node()
{
material = Shader::createMaterial();
setMaterial(material);
setFlag(OwnsMaterial, true);
QSGGeometry *g = new QSGGeometry(QSGGeometry::defaultAttributes_TexturedPoint2D(), 4);
QSGGeometry::updateTexturedRectGeometry(g, QRect(), QRect());
setGeometry(g);
setFlag(QSGNode::OwnsGeometry, true);
}
void setItem(QQuickItem* item) {
this->item = item;
}
void setUri(std::string uri) {
this->uri = uri;
}
void beginStream() {
stream = new MediaStream(uri);
stream->setFrameUpdater((FrameUpdater *) this);
boost::thread mediaThread(&MediaStream::run, stream);
}
void updateData(unsigned char**data, int frameWidth, int frameHeight)
{
material->state()->updateData(data, frameWidth, frameHeight);
markDirty(QSGNode::DirtyMaterial);//is this really needed?
QMetaObject::invokeMethod(item, &QQuickItem::update, Qt::QueuedConnection);
}
private:
QSGSimpleMaterial<State> *material;
MediaStream* stream;
QQuickItem* item;
std::string uri;
};
QSGNode * OpenGlMaterialQQuickItem::updatePaintNode(QSGNode *node, UpdatePaintNodeData *) //override
{
Node *n = static_cast<Node *>(node);
if (!node) {
n = new Node();
n->setItem(this);
n->setUri(this->uri);//TODO: How do I know that when updatePaintNode is called, the object will already have a defined uri?
n->beginStream();
}
QSGGeometry::updateTexturedRectGeometry(n->geometry(), boundingRect(), QRectF(0, 0, 1, 1));
//static_cast<QSGSimpleMaterial<State>*>(n->material())->state()->color = m_color;
n->markDirty(QSGNode::DirtyGeometry | QSGNode::DirtyMaterial);//what is this?
return n;
}
In case you want to see the original files:
Here's OpenGlMaterialQQuickItem.cpp:
OpenGlMaterialQQuickItem.h:
Here's main.qml:
https://github.com/lucaszanella/orwell/blob/a25cbde5f8441da05fd477cd58780e291da32a43/qt/main.qml