From a94d9c4bb136f434eb24d37805f9e2c8a971a96e Mon Sep 17 00:00:00 2001
From: Jared Bruni <jaredbruni@gmail.com>
Date: Thu, 23 Jan 2020 22:29:53 -0800
Subject: [PATCH] got video working with gl

---
 src/display_window.cpp |  6 ++--
 src/gl_display.cpp     | 74 +++++++++++++++++++++++++++++-------------
 src/gl_display.h       |  8 +++--
 3 files changed, 59 insertions(+), 29 deletions(-)

diff --git a/src/display_window.cpp b/src/display_window.cpp
index e489b28..6d137e5 100644
--- a/src/display_window.cpp
+++ b/src/display_window.cpp
@@ -30,13 +30,13 @@ void DisplayWindow::createControls() {
     img_label->setGeometry(0,0,640, 480);
 }
 void DisplayWindow::displayImage(const QImage &img) {
-    gl_display->setNewFrame(img);
-    QRect src(QPoint(0, 0), size());
+    gl_display->setNewFrame(img.copy());
+    /*QRect src(QPoint(0, 0), size());
     QPixmap p = QPixmap::fromImage(img).scaled(size(),Qt::KeepAspectRatio, Qt::FastTransformation);
     QRect dst(QPoint(0,0),p.size());
     dst.moveCenter(src.center());
     img_label->setGeometry(dst);
-    img_label->setPixmap(p);
+    img_label->setPixmap(p); */
 }
 
 void DisplayWindow::paintEvent(QPaintEvent *) {
diff --git a/src/gl_display.cpp b/src/gl_display.cpp
index d78fe1a..1e8a5a1 100644
--- a/src/gl_display.cpp
+++ b/src/gl_display.cpp
@@ -13,7 +13,7 @@ glDisplayWindow::glDisplayWindow(QWindow *parent)
     : QWindow(parent)
     , m_animating(false)
     , m_context(0)
-    , m_device(0)
+, m_device(0), updated(false)
 {
     setSurfaceType(QWindow::OpenGLSurface);
 }
@@ -27,6 +27,8 @@ void glDisplayWindow::render(QPainter *painter) {
 }
 
 void glDisplayWindow::initialize() {
+    resize(1280, 720);
+    glEnable(GL_TEXTURE_2D);
     glClearDepth(1.0f);
     glClearColor(0, 0, 0, 0);
     glMatrixMode(GL_PROJECTION);
@@ -35,35 +37,61 @@ void glDisplayWindow::initialize() {
     glEnable (GL_DEPTH_TEST);
 }
 
-void glDisplayWindow::setNewFrame(const QImage &new_one) {
-    frame_copy = new_one;
+void glDisplayWindow::setNewFrame(QImage image) {
+    frame = image;
+    updated = true;
 }
 
-unsigned int texID;
+void glDisplayWindow::updateTexture(QImage image) {
+    static int lazy = 0;
+    QImage new_one = image.mirrored();
+    if(lazy == 0) {
+        glEnable(GL_TEXTURE_2D);
+        glGenTextures(1, &tex);
+        glBindTexture(GL_TEXTURE_2D, tex);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, new_one.width(), new_one.height(), 0, GL_BGR, GL_UNSIGNED_BYTE, new_one.bits());
+        lazy = 1;
+    } else {
+        glBindTexture(GL_TEXTURE_2D, tex);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+        glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, new_one.width(), new_one.height(), GL_BGR, GL_UNSIGNED_BYTE, new_one.bits());
+    }
+}
 
 void glDisplayWindow::render() {
+    
     if (!m_device)
         m_device = new QOpenGLPaintDevice;
-    if(frame_copy.width()>100 && isVisible()) {
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-        glMatrixMode(GL_PROJECTION);
-        glLoadIdentity();
-        float aspect=(float)width()/(float)height();
-        
-        if(width() <= height())
-            glOrtho ( -5.0, 5.0, -5.0/aspect, 5.0/aspect, -5.0, 5.0);
-        else
-            glOrtho (-5.0*aspect, 5.0*aspect, -5.0, 5.0, -5.0, 5.0);
-        if(frame_copy.width() > 25 && frame_copy.height() > 25) {
-            glMatrixMode(GL_MODELVIEW);
-            glLoadIdentity();
-            glDrawPixels(frame_copy.width(), frame_copy.height(), GL_RGB,GL_UNSIGNED_BYTE,(unsigned char*)frame_copy.bits());
-            glFlush();
-        }
+    
+    if(updated == true && frame.width()>100 && frame.height()>100) {
+        updateTexture(frame);
+        updated = false;
     }
-    m_device->setPaintFlipped(true);
-    m_device->setSize(size() * devicePixelRatio());
-    m_device->setDevicePixelRatio(devicePixelRatio());
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    glOrtho(0, 1280, 0, 720, -1, 1);
+    glMatrixMode(GL_MODELVIEW);
+    glLoadIdentity();
+    glClear(GL_COLOR_BUFFER_BIT);
+    glBindTexture(GL_TEXTURE_2D, tex);
+    glEnable(GL_TEXTURE_2D);
+    glBegin(GL_QUADS);
+    glTexCoord2i(0, 0); glVertex2i(0, 0);
+    glTexCoord2i(0, 1); glVertex2i(0, 720);
+    glTexCoord2i(1, 1); glVertex2i(1280, 720);
+    glTexCoord2i(1, 0); glVertex2i(1280, 0);
+    glEnd();
+    glDisable(GL_TEXTURE_2D);
+    glBindTexture(GL_TEXTURE_2D, 0);
+    //m_device->setSize(size() * devicePixelRatio());
+    //m_device->setDevicePixelRatio(devicePixelRatio());
     QPainter painter(m_device);
     render(&painter);
 }
diff --git a/src/gl_display.h b/src/gl_display.h
index aaf2889..6d7d036 100644
--- a/src/gl_display.h
+++ b/src/gl_display.h
@@ -24,8 +24,8 @@ public:
     virtual void initialize();
 
     void setAnimating(bool animating);
-    void setNewFrame(const QImage &image);
-    
+    void setNewFrame(QImage image);
+    void updateTexture(QImage image);
 public slots:
     void renderLater();
     void renderNow();
@@ -37,9 +37,11 @@ protected:
 
 private:
     bool m_animating;
-    QImage frame_copy;
     QOpenGLContext *m_context;
     QOpenGLPaintDevice *m_device;
+    GLuint tex;
+    QImage frame;
+    bool updated;
 };
 
 #endif