Fixed cleanup method on shader classes. Fixes #1179

sdrgui/gui/glscope.cpp

@@ -2074,6 +2074,7 @@ void GLScope::cleanup()
 {
     //makeCurrent();
     m_glShaderSimple.cleanup();
+    m_glShaderColors.cleanup();
     m_glShaderBottom1Scale.cleanup();
     m_glShaderBottom2Scale.cleanup();
     m_glShaderLeft1Scale.cleanup();

sdrgui/gui/glshadercolors.cpp

@@ -107,6 +107,10 @@ void GLShaderColors::draw(unsigned int mode, const QMatrix4x4& transformMatrix,
 
 void GLShaderColors::cleanup()
 {
+	if (!QOpenGLContext::currentContext()) {
+		return;
+	}
+
 	if (m_program)
 	{
 		delete m_program;

sdrgui/gui/glshadersimple.cpp

@@ -103,10 +103,10 @@ void GLShaderSimple::draw(unsigned int mode, const QMatrix4x4& transformMatrix,
 
 void GLShaderSimple::cleanup()
 {
-	if (m_program)
+	if (QOpenGLContext::currentContext() && m_program)
 	{
 		delete m_program;
-		m_program = 0;
+		m_program = nullptr;
 	}
 }
 

sdrgui/gui/glshadertextured.cpp

@@ -198,6 +198,10 @@ void GLShaderTextured::drawMutable(unsigned int mode, const QMatrix4x4& transfor
 
 void GLShaderTextured::cleanup()
 {
+	if (!QOpenGLContext::currentContext()) {
+		return;
+	}
+
 	if (m_program)
     {
 		delete m_program;

sdrgui/gui/glshadertvarray.cpp

@@ -272,6 +272,10 @@ void GLShaderTVArray::cleanup()
 
     m_objCurrentRow = nullptr;
 
+	if (!QOpenGLContext::currentContext()) {
+		return;
+	}
+
     if (m_objProgram)
     {
         delete m_objProgram;

sdrgui/gui/tvscreenanalog.cpp

@@ -86,6 +86,10 @@ TVScreenAnalog::~TVScreenAnalog()
 
 void TVScreenAnalog::cleanup()
 {
+	if (!QOpenGLContext::currentContext()) {
+		return;
+	}
+
 	if (m_shader)
 	{
 		delete m_shader;