Multi pass

apps/LoopThroughWithOpenGLCompositing/gl/renderer/RenderTargetPool.cpp

@@ -69,11 +69,10 @@ bool RenderTargetPool::ReserveTemporaryTargets(
 	GLenum pixelType,
 	std::string& error)
 {
-	if (!mTemporaryTargets.empty())
-	{
-		error = "Temporary render targets were already initialized.";
-		return false;
-	}
+	if (mTemporaryTargets.size() == count)
+		return true;
+
+	DestroyTemporaryTargets();
 
 	mTemporaryTargets.resize(count);
 	for (std::size_t index = 0; index < mTemporaryTargets.size(); ++index)
@@ -105,6 +104,18 @@ bool RenderTargetPool::ReserveTemporaryTargets(
 	return true;
 }
 
+void RenderTargetPool::DestroyTemporaryTargets()
+{
+	for (RenderTarget& target : mTemporaryTargets)
+	{
+		if (target.framebuffer != 0)
+			glDeleteFramebuffers(1, &target.framebuffer);
+		if (target.texture != 0)
+			glDeleteTextures(1, &target.texture);
+	}
+	mTemporaryTargets.clear();
+}
+
 void RenderTargetPool::Destroy()
 {
 	for (RenderTarget& target : mTargets)
@@ -116,14 +127,7 @@ void RenderTargetPool::Destroy()
 		target = RenderTarget();
 	}
 
-	for (RenderTarget& target : mTemporaryTargets)
-	{
-		if (target.framebuffer != 0)
-			glDeleteFramebuffers(1, &target.framebuffer);
-		if (target.texture != 0)
-			glDeleteTextures(1, &target.texture);
-	}
-	mTemporaryTargets.clear();
+	DestroyTemporaryTargets();
 }
 
 const RenderTarget& RenderTargetPool::Target(RenderTargetId id) const