From 0d8b7c55ef1d1a4f6688f770461840c104f7dabb Mon Sep 17 00:00:00 2001
From: Rachael Alexanderson <eruanna@drdteam.org>
Date: Mon, 26 Jun 2017 06:33:59 -0400
Subject: [PATCH] - added a grayscale formula selector

---
 src/gl/renderer/gl_postprocess.cpp    |  2 ++
 src/gl/shaders/gl_presentshader.cpp   |  1 +
 src/gl/shaders/gl_presentshader.h     |  1 +
 src/gl/stereo3d/gl_interleaved3d.cpp  |  3 +++
 src/gl/system/gl_menu.cpp             | 10 +++++++++-
 wadsrc/static/shaders/glsl/present.fp |  6 +++++-
 6 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/gl/renderer/gl_postprocess.cpp b/src/gl/renderer/gl_postprocess.cpp
index efc9e1911..21eaf874d 100644
--- a/src/gl/renderer/gl_postprocess.cpp
+++ b/src/gl/renderer/gl_postprocess.cpp
@@ -150,6 +150,7 @@ CVAR(Float, gl_menu_blur, -1.0f, CVAR_ARCHIVE)
 EXTERN_CVAR(Float, vid_brightness)
 EXTERN_CVAR(Float, vid_contrast)
 EXTERN_CVAR(Float, vid_saturation)
+EXTERN_CVAR(Int, gl_satformula)
 
 
 void FGLRenderer::RenderScreenQuad()
@@ -867,6 +868,7 @@ void FGLRenderer::DrawPresentTexture(const GL_IRECT &box, bool applyGamma)
 		mPresentShader->Contrast.Set(clamp<float>(vid_contrast, 0.1f, 3.f));
 		mPresentShader->Brightness.Set(clamp<float>(vid_brightness, -0.8f, 0.8f));
 		mPresentShader->Saturation.Set(clamp<float>(vid_saturation, -15.0f, 15.f));
+		mPresentShader->GrayFormula.Set(static_cast<int>(gl_satformula));
 	}
 	mPresentShader->Scale.Set(mScreenViewport.width / (float)mBuffers->GetWidth(), mScreenViewport.height / (float)mBuffers->GetHeight());
 	RenderScreenQuad();
diff --git a/src/gl/shaders/gl_presentshader.cpp b/src/gl/shaders/gl_presentshader.cpp
index 8fdf623d9..06056f539 100644
--- a/src/gl/shaders/gl_presentshader.cpp
+++ b/src/gl/shaders/gl_presentshader.cpp
@@ -47,6 +47,7 @@ void FPresentShaderBase::Init(const char * vtx_shader_name, const char * program
 	Contrast.Init(mShader, "Contrast");
 	Brightness.Init(mShader, "Brightness");
 	Saturation.Init(mShader, "Saturation");
+	GrayFormula.Init(mShader, "GrayFormula");
 	Scale.Init(mShader, "UVScale");
 }
 
diff --git a/src/gl/shaders/gl_presentshader.h b/src/gl/shaders/gl_presentshader.h
index acb3f50eb..377a6a4f2 100644
--- a/src/gl/shaders/gl_presentshader.h
+++ b/src/gl/shaders/gl_presentshader.h
@@ -13,6 +13,7 @@ public:
 	FBufferedUniform1f Contrast;
 	FBufferedUniform1f Brightness;
 	FBufferedUniform1f Saturation;
+	FBufferedUniform1i GrayFormula;
 	FBufferedUniform2f Scale;
 
 protected:
diff --git a/src/gl/stereo3d/gl_interleaved3d.cpp b/src/gl/stereo3d/gl_interleaved3d.cpp
index a499f6e0e..4729fbf77 100644
--- a/src/gl/stereo3d/gl_interleaved3d.cpp
+++ b/src/gl/stereo3d/gl_interleaved3d.cpp
@@ -44,6 +44,7 @@
 EXTERN_CVAR(Float, vid_saturation)
 EXTERN_CVAR(Float, vid_brightness)
 EXTERN_CVAR(Float, vid_contrast)
+EXTERN_CVAR(Int, gl_satformula)
 EXTERN_CVAR(Bool, fullscreen)
 EXTERN_CVAR(Int, win_x) // screen pixel position of left of display window
 EXTERN_CVAR(Int, win_y) // screen pixel position of top of display window
@@ -101,6 +102,7 @@ static void prepareInterleavedPresent(FPresentStereoShaderBase& shader)
 		shader.InvGamma.Set(1.0f);
 		shader.Contrast.Set(1.0f);
 		shader.Brightness.Set(0.0f);
+		shader.Saturation.Set(1.0f);
 	}
 	else
 	{
@@ -108,6 +110,7 @@ static void prepareInterleavedPresent(FPresentStereoShaderBase& shader)
 		shader.Contrast.Set(clamp<float>(vid_contrast, 0.1f, 3.f));
 		shader.Brightness.Set(clamp<float>(vid_brightness, -0.8f, 0.8f));
 		shader.Saturation.Set(clamp<float>(vid_saturation, -15.0f, 15.0f));
+		shader.GrayFormula.Set(static_cast<int>(gl_satformula));
 	}
 	shader.Scale.Set(
 		GLRenderer->mScreenViewport.width / (float)GLRenderer->mBuffers->GetWidth(),
diff --git a/src/gl/system/gl_menu.cpp b/src/gl/system/gl_menu.cpp
index 5813613b4..489ad4a9d 100644
--- a/src/gl/system/gl_menu.cpp
+++ b/src/gl/system/gl_menu.cpp
@@ -77,7 +77,15 @@ CUSTOM_CVAR (Float, vid_saturation, 1.f, CVAR_ARCHIVE|CVAR_GLOBALCONFIG)
 {
 	if (screen != NULL)
 	{
-		screen->SetGamma(Gamma); //SetContrast (self);
+		screen->SetGamma(Gamma);
+	}
+}
+
+CUSTOM_CVAR(Int, gl_satformula, 1, CVAR_ARCHIVE|CVAR_GLOBALCONFIG)
+{
+	if (screen != NULL)
+	{
+		screen->SetGamma(Gamma);
 	}
 }
 
diff --git a/wadsrc/static/shaders/glsl/present.fp b/wadsrc/static/shaders/glsl/present.fp
index 9a53e0eb5..eff874ed2 100644
--- a/wadsrc/static/shaders/glsl/present.fp
+++ b/wadsrc/static/shaders/glsl/present.fp
@@ -7,12 +7,16 @@ uniform float InvGamma;
 uniform float Contrast;
 uniform float Brightness;
 uniform float Saturation;
+uniform int GrayFormula;
 
 vec4 ApplyGamma(vec4 c)
 {
 	vec3 valgray;
 	if (Saturation != 1.0) // attempt to cool things a bit, this calculation makes the GPU run really hot
-		valgray = (0.3 * c.r + 0.59 * c.g + 0.11 * c.b) * (1 - Saturation) + c.rgb * Saturation;
+		if (GrayFormula == 0)
+			valgray = vec3(c.r + c.g + c.b) * (1 - Saturation) / 3 + c.rgb * Saturation;
+		else
+			valgray = vec3(0.3 * c.r + 0.56 * c.g + 0.14 * c.b) * (1 - Saturation) + c.rgb * Saturation;
 	else
 		valgray = c.rgb;
 	vec3 val = valgray * Contrast - (Contrast - 1.0) * 0.5;