From 580d5b82595893c83f7bf715c94de20b70745ae4 Mon Sep 17 00:00:00 2001
From: ronag <ronag@362d55ac-95cf-4e76-9f9a-cbaa9c17b72d>
Date: Thu, 25 Aug 2011 14:20:46 +0000
Subject: [PATCH] 2.0. image_mixer: Added "keyer" concept.

git-svn-id: https://casparcg.svn.sourceforge.net/svnroot/casparcg/server/branches/2.0.0.2@1285 362d55ac-95cf-4e76-9f9a-cbaa9c17b72d
---
 core/mixer/image/image_kernel.cpp |  6 ++++--
 core/mixer/image/image_kernel.h   | 11 +++++++++++
 core/mixer/image/image_mixer.cpp  |  3 +--
 core/mixer/image/image_shader.cpp | 15 +++++++++------
 4 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/core/mixer/image/image_kernel.cpp b/core/mixer/image/image_kernel.cpp
index 1fd83d91d..9e5e4de0c 100644
--- a/core/mixer/image/image_kernel.cpp
+++ b/core/mixer/image/image_kernel.cpp
@@ -120,14 +120,16 @@ struct image_kernel::implementation : boost::noncopyable
 
 			shader_->set("background",	texture_id::background);
 			shader_->set("blend_mode",	params.blend_mode);
+			shader_->set("keyer",		params.keyer);
 		}
 		else
 		{
-			switch(params.blend_mode)
+			switch(params.keyer)
 			{
-			case blend_mode::mix:
+			case keyer::additive:
 				ogl.blend_func(GL_ONE, GL_ONE);	
 				break;
+			case keyer::linear:
 			default:				
 				ogl.blend_func(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);	
 			}		
diff --git a/core/mixer/image/image_kernel.h b/core/mixer/image/image_kernel.h
index 31e9098e4..9db54b321 100644
--- a/core/mixer/image/image_kernel.h
+++ b/core/mixer/image/image_kernel.h
@@ -33,18 +33,29 @@ namespace caspar { namespace core {
 class device_buffer;
 class ogl_device;
 
+struct keyer
+{
+	enum type
+	{
+		linear = 0,
+		additive
+	};
+};
+
 struct draw_params
 {
 	pixel_format_desc						pix_desc;
 	std::vector<safe_ptr<device_buffer>>	textures;
 	frame_transform							transform;
 	blend_mode::type						blend_mode;
+	keyer::type								keyer;
 	std::shared_ptr<device_buffer>			background;
 	std::shared_ptr<device_buffer>			local_key;
 	std::shared_ptr<device_buffer>			layer_key;
 
 	draw_params() 
 		: blend_mode(blend_mode::normal)
+		, keyer(keyer::linear)
 	{
 	}
 };
diff --git a/core/mixer/image/image_mixer.cpp b/core/mixer/image/image_mixer.cpp
index 393c8a714..35e95f0a3 100644
--- a/core/mixer/image/image_mixer.cpp
+++ b/core/mixer/image/image_mixer.cpp
@@ -178,7 +178,6 @@ private:
 		draw_params.pix_desc				= std::move(item.pix_desc);
 		draw_params.textures				= std::move(item.textures);
 		draw_params.transform				= std::move(item.transform);
-		draw_params.blend_mode				= blend_mode::normal;
 
 		if(item.transform.is_key)
 		{
@@ -198,7 +197,7 @@ private:
 			draw_params.local_key			= std::move(local_key_buffer);
 			draw_params.layer_key			= layer_key_buffer;
 
-			draw_params.blend_mode			= blend_mode::mix;
+			draw_params.keyer				= keyer::additive;
 
 			kernel_.draw(channel_.ogl(), std::move(draw_params));
 		}
diff --git a/core/mixer/image/image_shader.cpp b/core/mixer/image/image_shader.cpp
index 85ceb4cca..6d89630c2 100644
--- a/core/mixer/image/image_shader.cpp
+++ b/core/mixer/image/image_shader.cpp
@@ -69,12 +69,15 @@ std::string get_blend_color_func()
 	"																					\n"																			  
 	"vec4 blend(vec4 fore)																\n"
 	"{																					\n"
-	"   vec4 back = texture2D(background, gl_TexCoord[1].st).bgra;						\n"	
-	"																					\n"		
-	"	if(blend_mode == 29) // mix														\n"
-	"		return fore + back;															\n"
-	"																					\n"		
+	"   vec4 back = texture2D(background, gl_TexCoord[1].st).bgra;						\n"		
 	"	fore.rgb = get_blend_color(back.rgb, fore.rgb);									\n"
+	"																					\n"		
+	"	switch(keyer)																	\n"
+	"	{																				\n"
+	"		case 0: return fore + (1.0-fore.a)*back; // linear							\n"
+	"		case 1: return fore + back; // additive										\n"
+	"	}																				\n"
+	"																					\n"					
 	"	return fore + (1.0-fore.a)*back;												\n"
 	"}																					\n";			
 }
@@ -119,7 +122,7 @@ std::string get_fragment(bool blend_modes)
 	"uniform bool		has_local_key;													\n"
 	"uniform bool		has_layer_key;													\n"
 	"uniform int		blend_mode;														\n"
-	"uniform int		alpha_mode;														\n"
+	"uniform int		keyer;															\n"
 	"uniform int		pixel_format;													\n"
 	"																					\n"
 	"uniform float		opacity;														\n"
-- 
2.39.2