From daeef50aa6ae7116b5b2d681498023ea4a46abe1 Mon Sep 17 00:00:00 2001
From: itsmattkc <itsmattkc@gmail.com>
Date: Sat, 23 Jun 2018 17:01:19 -0700
Subject: [PATCH] blending modes added (#54)

---
 effects/effects.h           |  2 ++
 effects/transformeffect.cpp | 34 ++++++++++++++++++++++++++++++++++
 olive.pro.user              |  2 +-
 ui/viewerwidget.cpp         |  4 +++-
 4 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/effects/effects.h b/effects/effects.h
index bde898949..58683dc1f 100644
--- a/effects/effects.h
+++ b/effects/effects.h
@@ -6,6 +6,7 @@
 #include <QXmlStreamWriter>
 class QSpinBox;
 class QCheckBox;
+class QComboBox;
 class LabelSlider;
 
 enum VideoEffects {
@@ -43,6 +44,7 @@ public:
     LabelSlider* anchor_x_box;
     LabelSlider* anchor_y_box;
     LabelSlider* opacity;
+    QComboBox* blend_mode_box;
 public slots:
 	void toggle_uniform_scale(bool enabled);
 private:
diff --git a/effects/transformeffect.cpp b/effects/transformeffect.cpp
index bb411f289..db6b51fd0 100644
--- a/effects/transformeffect.cpp
+++ b/effects/transformeffect.cpp
@@ -7,6 +7,7 @@
 #include <QSpinBox>
 #include <QCheckBox>
 #include <QOpenGLFunctions>
+#include <QComboBox>
 
 #include "ui/collapsiblewidget.h"
 #include "project/clip.h"
@@ -14,6 +15,10 @@
 #include "io/media.h"
 #include "ui/labelslider.h"
 
+#define BLEND_MODE_NORMAL 0
+#define BLEND_MODE_SCREEN 1
+#define BLEND_MODE_MULTIPLY 2
+
 TransformEffect::TransformEffect(Clip* c) : Effect(c) {
     setup_effect(EFFECT_TYPE_VIDEO, VIDEO_TRANSFORM_EFFECT);
 
@@ -56,6 +61,13 @@ TransformEffect::TransformEffect(Clip* c) : Effect(c) {
     opacity->set_maximum_value(100);
 	ui_layout->addWidget(opacity, 5, 1);
 
+    ui_layout->addWidget(new QLabel("Blend Mode:"), 6, 0);
+    blend_mode_box = new QComboBox();
+    blend_mode_box->addItem("Normal", BLEND_MODE_NORMAL);
+    blend_mode_box->addItem("Screen", BLEND_MODE_SCREEN);
+    blend_mode_box->addItem("Multiply", BLEND_MODE_MULTIPLY);
+    ui_layout->addWidget(blend_mode_box, 6, 1);
+
 	ui->setLayout(ui_layout);
 
 	container->setContents(ui);
@@ -72,6 +84,7 @@ TransformEffect::TransformEffect(Clip* c) : Effect(c) {
     anchor_x_box->set_default_value(default_anchor_x);
     anchor_y_box->set_default_value(default_anchor_y);
     opacity->set_default_value(100);
+    blend_mode_box->setCurrentIndex(0);
 
     connect(position_x, SIGNAL(valueChanged()), this, SLOT(field_changed()));
     connect(position_y, SIGNAL(valueChanged()), this, SLOT(field_changed()));
@@ -83,6 +96,7 @@ TransformEffect::TransformEffect(Clip* c) : Effect(c) {
     connect(opacity, SIGNAL(valueChanged()), this, SLOT(field_changed()));
 	connect(uniform_scale_box, SIGNAL(toggled(bool)), this, SLOT(toggle_uniform_scale(bool)));
 	connect(uniform_scale_box, SIGNAL(toggled(bool)), this, SLOT(field_changed()));
+    connect(blend_mode_box, SIGNAL(currentIndexChanged(int)), this, SLOT(field_changed()));
 }
 
 Effect* TransformEffect::copy(Clip* c) {
@@ -96,6 +110,7 @@ Effect* TransformEffect::copy(Clip* c) {
     t->anchor_x_box->set_value(anchor_x_box->value());
     t->anchor_y_box->set_value(anchor_y_box->value());
     t->opacity->set_value(opacity->value());
+    t->blend_mode_box->setCurrentIndex(blend_mode_box->currentIndex());
     return t;
 }
 
@@ -129,6 +144,9 @@ void TransformEffect::load(QXmlStreamReader *stream) {
         } else if (stream->isStartElement() && stream->name() == "opacity") {
             stream->readNext();
             opacity->set_value(stream->text().toFloat());
+        } else if (stream->isStartElement() && stream->name() == "blendmode") {
+            stream->readNext();
+            blend_mode_box->setCurrentIndex(stream->text().toInt());
         }
     }
 }
@@ -143,6 +161,7 @@ void TransformEffect::save(QXmlStreamWriter *stream) {
     stream->writeTextElement("anchorx", QString::number(anchor_x_box->value()));
     stream->writeTextElement("anchory", QString::number(anchor_y_box->value()));
     stream->writeTextElement("opacity", QString::number(opacity->value()));
+    stream->writeTextElement("blendmode", QString::number(blend_mode_box->currentIndex()));
 }
 
 void TransformEffect::toggle_uniform_scale(bool enabled) {
@@ -165,6 +184,21 @@ void TransformEffect::process_gl(int* anchor_x, int* anchor_y) {
 	float sy = (uniform_scale_box->isChecked()) ? sx : scale_y->value()*0.01;
 	glScalef(sx, sy, 1);
 
+    // blend mode
+    switch (blend_mode_box->currentData().toInt()) {
+    case BLEND_MODE_NORMAL:
+        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+        break;
+    case BLEND_MODE_SCREEN:
+        glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_COLOR);
+        break;
+    case BLEND_MODE_MULTIPLY:
+        glBlendFunc(GL_DST_COLOR, GL_ZERO);
+        break;
+    default:
+        qDebug() << "[ERROR] Invalid blend mode. This is a bug - please contact developers";
+    }
+
 	// opacity
 	glColor4f(1.0, 1.0, 1.0, opacity->value()*0.01);
 }
diff --git a/olive.pro.user b/olive.pro.user
index aeaf887a2..a2502092b 100644
--- a/olive.pro.user
+++ b/olive.pro.user
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE QtCreatorProject>
-<!-- Written by QtCreator 4.6.2, 2018-06-23T02:01:56. -->
+<!-- Written by QtCreator 4.6.2, 2018-06-23T14:26:22. -->
 <qtcreator>
  <data>
   <variable>EnvironmentId</variable>
diff --git a/ui/viewerwidget.cpp b/ui/viewerwidget.cpp
index 14903dc8a..2a7b4c000 100644
--- a/ui/viewerwidget.cpp
+++ b/ui/viewerwidget.cpp
@@ -41,7 +41,7 @@ void ViewerWidget::initializeGL() {
     glMatrixMode(GL_PROJECTION);
     glEnable(GL_TEXTURE_2D);
     glEnable(GL_BLEND);
-    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+//    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 }
 
 //void ViewerWidget::resizeGL(int w, int h)
@@ -58,6 +58,8 @@ void ViewerWidget::paintGL()
 
     glClear(GL_COLOR_BUFFER_BIT);
 
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
     long playhead = panel_timeline->playhead;
 
     handle_media(sequence, playhead, multithreaded);