From 72df21e57ccefdf749fa9f56d48b8997e50963c7 Mon Sep 17 00:00:00 2001
From: itsmattkc <itsmattkc@gmail.com>
Date: Wed, 9 Jan 2019 12:22:50 +1100
Subject: [PATCH] don't bind shaders if they didn't compile

---
 project/effect.cpp  | 21 +++++++++++++++++----
 project/effect.h    |  1 +
 ui/viewerwidget.cpp |  4 ++--
 3 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/project/effect.cpp b/project/effect.cpp
index 6315ade00..add2c2a5b 100644
--- a/project/effect.cpp
+++ b/project/effect.cpp
@@ -800,9 +800,18 @@ void Effect::open() {
 		} else {
 			glslProgram = new QOpenGLShaderProgram();
 			validate_meta_path();
-			if (!vertPath.isEmpty()) glslProgram->addShaderFromSourceFile(QOpenGLShader::Vertex, meta->path + "/" + vertPath);
-			if (!fragPath.isEmpty()) glslProgram->addShaderFromSourceFile(QOpenGLShader::Fragment, meta->path + "/" + fragPath);
-			glslProgram->link();
+			bool glsl_compiled = true;
+			if (!vertPath.isEmpty()) {
+				if (!glslProgram->addShaderFromSourceFile(QOpenGLShader::Vertex, meta->path + "/" + vertPath)) {
+					glsl_compiled = false;
+				}
+			}
+			if (!fragPath.isEmpty()) {
+				if (!glslProgram->addShaderFromSourceFile(QOpenGLShader::Fragment, meta->path + "/" + fragPath)) {
+					glsl_compiled = false;
+				}
+			}
+			if (glsl_compiled) glslProgram->link();
 			isOpen = true;
 		}
 	} else {
@@ -826,12 +835,16 @@ void Effect::close() {
 	isOpen = false;
 }
 
+bool Effect::is_glsl_linked() {
+	return glslProgram != NULL && glslProgram->isLinked();
+}
+
 void Effect::startEffect() {
 	if (!isOpen) {
 		open();
 		dout << "[WARNING] Tried to start a closed effect - opening";
 	}
-	if (enable_shader) bound = glslProgram->bind();
+	if (enable_shader && glslProgram->isLinked()) bound = glslProgram->bind();
 }
 
 void Effect::endEffect() {
diff --git a/project/effect.h b/project/effect.h
index 284bd9678..b11bf8fae 100644
--- a/project/effect.h
+++ b/project/effect.h
@@ -142,6 +142,7 @@ public:
 	bool is_open();
 	void open();
 	void close();
+	bool is_glsl_linked();
 	virtual void startEffect();
 	virtual void endEffect();
 
diff --git a/ui/viewerwidget.cpp b/ui/viewerwidget.cpp
index 659b344f9..f46b8c1c3 100644
--- a/ui/viewerwidget.cpp
+++ b/ui/viewerwidget.cpp
@@ -189,7 +189,7 @@ void ViewerWidget::initializeGL() {
 //}
 
 void ViewerWidget::paintEvent(QPaintEvent *e) {
-    if (!rendering && context()->thread() == this->thread()) {
+	if (!rendering && context()->thread() == this->thread()) {
 		makeCurrent();
 		QOpenGLWidget::paintEvent(e);
 	}
@@ -429,7 +429,7 @@ void ViewerWidget::process_effect(Clip* c, Effect* e, double timecode, GLTexture
 		}
 		if (e->enable_shader || e->enable_superimpose) {
 			e->startEffect();
-			if (e->enable_shader) {
+			if (e->enable_shader && e->is_glsl_linked()) {
 				e->process_shader(timecode, coords);
 				composite_texture = draw_clip(c->fbo[fbo_switcher], composite_texture, true);
 				fbo_switcher = !fbo_switcher;