From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 27 Jul 2019 23:05:05 +0000 (+0300)
Subject: Add an alpha channel flag to Pipeline
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=39488946c441f4007396e438f522609a8b2943ce

Add an alpha channel flag to Pipeline
---

diff --git a/source/pipeline.cpp b/source/pipeline.cpp
index 53b51d79..fa06fc5c 100644
--- a/source/pipeline.cpp
+++ b/source/pipeline.cpp
@@ -38,6 +38,7 @@ void Pipeline::init(unsigned w, unsigned h)
 	width = w;
 	height = h;
 	hdr = false;
+	alpha = false;
 	samples = 0;
 	target_ms = 0;
 	target[0] = 0;
@@ -69,6 +70,24 @@ void Pipeline::set_hdr(bool h)
 	}
 }
 
+void Pipeline::set_alpha(bool a)
+{
+	if(a==alpha)
+		return;
+
+	bool old_alpha = alpha;
+	alpha = a;
+	try
+	{
+		create_targets(2);
+	}
+	catch(...)
+	{
+		alpha = old_alpha;
+		throw;
+	}
+}
+
 void Pipeline::set_multisample(unsigned s)
 {
 	if(s==samples)
@@ -269,7 +288,7 @@ void Pipeline::create_targets(unsigned recreate)
 		target_ms = 0;
 	}
 
-	PixelFormat color_pf = (hdr ? RGB16F : RGB);
+	PixelFormat color_pf = (hdr ? (alpha ? RGBA16F : RGB16F) : (alpha ? RGBA : RGB));
 	RenderTargetFormat fmt = (RENDER_COLOR,color_pf, RENDER_DEPTH);
 	if(!postproc.empty() || samples)
 	{
diff --git a/source/pipeline.h b/source/pipeline.h
index 0d38aaec..e8ffaf5e 100644
--- a/source/pipeline.h
+++ b/source/pipeline.h
@@ -80,6 +80,7 @@ private:
 	unsigned width;
 	unsigned height;
 	bool hdr;
+	bool alpha;
 	unsigned samples;
 	RenderTarget *target[2];
 	RenderTarget *target_ms;
@@ -97,6 +98,10 @@ public:
 	A ColorCurve postprocessor is recommended for full benefit. */
 	void set_hdr(bool);
 
+	/* Enable or disable alpha channel.  When enabled, all render targets are
+	created with an RGBA pixel format instead of RGB. */
+	void set_alpha(bool);
+
 	void set_multisample(unsigned);
 
 	unsigned get_width() const { return width; }
diff --git a/source/pipelinebuilder.cpp b/source/pipelinebuilder.cpp
index fcd5efbc..51e9cc85 100644
--- a/source/pipelinebuilder.cpp
+++ b/source/pipelinebuilder.cpp
@@ -36,6 +36,7 @@ void PipelineBuilder::set_postprocessor(const string &name, PostProcessor &pproc
 void PipelineBuilder::build(Pipeline &pipeline) const
 {
 	pipeline.set_hdr(tmpl.get_hdr());
+	pipeline.set_alpha(tmpl.get_alpha());
 	unsigned samples = min(tmpl.get_maximum_multisample(), Renderbuffer::get_max_samples());
 	if(samples<tmpl.get_required_multisample())
 		throw invalid_operation("PipelineBuilder::build");
diff --git a/source/pipelinetemplate.cpp b/source/pipelinetemplate.cpp
index 14f6e2c0..b78b4c40 100644
--- a/source/pipelinetemplate.cpp
+++ b/source/pipelinetemplate.cpp
@@ -15,6 +15,7 @@ namespace GL {
 
 PipelineTemplate::PipelineTemplate():
 	hdr(false),
+	alpha(false),
 	required_multisample(0),
 	max_multisample(0)
 { }
@@ -71,6 +72,7 @@ PipelineTemplate::Loader::Loader(PipelineTemplate &t, Collection &c):
 void PipelineTemplate::Loader::init()
 {
 	add("hdr", &PipelineTemplate::hdr);
+	add("alpha", &PipelineTemplate::alpha);
 	add("multisample", &Loader::multisample);
 	add("multisample", &Loader::multisample_range);
 	add("pass", &Loader::pass);
diff --git a/source/pipelinetemplate.h b/source/pipelinetemplate.h
index a18eead4..fb24ea29 100644
--- a/source/pipelinetemplate.h
+++ b/source/pipelinetemplate.h
@@ -106,6 +106,7 @@ private:
 	typedef DataFile::LoadableTypeRegistry<PostProcLoader, PostProcLoader::AddPostProc> PostProcessorRegistry;
 
 	bool hdr;
+	bool alpha;
 	unsigned required_multisample;
 	unsigned max_multisample;
 	PassArray passes;
@@ -116,6 +117,7 @@ public:
 	~PipelineTemplate();
 
 	bool get_hdr() const { return hdr; }
+	bool get_alpha() const { return alpha; }
 	unsigned get_required_multisample() const { return required_multisample; }
 	unsigned get_maximum_multisample() const { return max_multisample; }
 	const PassArray &get_passes() const { return passes; }