Revert "- add dithering to present shader"

This reverts commit 60ae0915b9.

This was extremely slow on intel, the dither matrix was recreated on every frame even when not used.

src/gl/renderer/gl_postprocess.cpp

@@ -155,8 +155,6 @@ EXTERN_CVAR(Float, vid_contrast)
 EXTERN_CVAR(Float, vid_saturation)
 EXTERN_CVAR(Int, gl_satformula)
 
-CVAR(Bool, gl_dither, false, CVAR_ARCHIVE | CVAR_GLOBALCONFIG | CVAR_NOINITCALL)
-
 void FGLRenderer::RenderScreenQuad()
 {
 	mVBO->BindVBO();
@@ -887,7 +885,6 @@ void FGLRenderer::DrawPresentTexture(const GL_IRECT &box, bool applyGamma)
 		mPresentShader->Saturation.Set(clamp<float>(vid_saturation, -15.0f, 15.f));
 		mPresentShader->GrayFormula.Set(static_cast<int>(gl_satformula));
 	}
-	mPresentShader->ColorScale.Set(static_cast<float>(gl_dither ? 255.0f : 0.0f));
 	mPresentShader->Scale.Set(mScreenViewport.width / (float)mBuffers->GetWidth(), mScreenViewport.height / (float)mBuffers->GetHeight());
 	RenderScreenQuad();
 }

src/gl/shaders/gl_presentshader.cpp

@@ -49,7 +49,6 @@ void FPresentShaderBase::Init(const char * vtx_shader_name, const char * program
 	Saturation.Init(mShader, "Saturation");
 	GrayFormula.Init(mShader, "GrayFormula");
 	Scale.Init(mShader, "UVScale");
-	ColorScale.Init(mShader, "ColorScale");
 }
 
 void FPresentShader::Bind()

src/gl/shaders/gl_presentshader.h

@@ -15,7 +15,6 @@ public:
 	FBufferedUniform1f Saturation;
 	FBufferedUniform1i GrayFormula;
 	FBufferedUniform2f Scale;
-	FBufferedUniform1f ColorScale;
 
 protected:
 	virtual void Init(const char * vtx_shader_name, const char * program_name);

src/gl/stereo3d/gl_interleaved3d.cpp

@@ -45,7 +45,6 @@ EXTERN_CVAR(Float, vid_saturation)
 EXTERN_CVAR(Float, vid_brightness)
 EXTERN_CVAR(Float, vid_contrast)
 EXTERN_CVAR(Int, gl_satformula)
-EXTERN_CVAR(Bool, gl_dither)
 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
@@ -113,7 +112,6 @@ static void prepareInterleavedPresent(FPresentStereoShaderBase& shader)
 		shader.Saturation.Set(clamp<float>(vid_saturation, -15.0f, 15.0f));
 		shader.GrayFormula.Set(static_cast<int>(gl_satformula));
 	}
-	shader.ColorScale.Set(static_cast<float>(gl_dither ? 255.0f : 0.0f));
 	shader.Scale.Set(
 		GLRenderer->mScreenViewport.width / (float)GLRenderer->mBuffers->GetWidth(),
 		GLRenderer->mScreenViewport.height / (float)GLRenderer->mBuffers->GetHeight());

wadsrc/static/language.enu

@@ -2813,7 +2813,6 @@ GLPREFMNU_LENS					= "Lens distortion effect";
 GLPREFMNU_SSAO					= "Ambient occlusion quality";
 GLPREFMNU_SSAO_PORTALS			= "Portals with AO";
 GLPREFMNU_FXAA					= "FXAA Quality";
-GLPREFMNU_DITHER				= "Dither output";
 GLPREFMNU_PALTONEMAPORDER		= "Tonemap Palette Order";
 GLPREFMNU_PALTONEMAPPOWER		= "Tonemap Palette Exponent";
 GLPREFMNU_SWLMBANDED			= "Banded SW Lightmode";

wadsrc/static/menudef.txt

@@ -2363,7 +2363,6 @@ OptionMenu "OpenGLOptions" protected
 	Option "$GLPREFMNU_SSAO",		 			gl_ssao,						"SSAOModes"
 	Slider "$GLPREFMNU_SSAO_PORTALS",			gl_ssao_portals,				0.0, 4.0, 1.0, 0
 	Option "$GLPREFMNU_FXAA",		 			gl_fxaa,						"FXAAQuality"
-	Option "$GLPREFMNU_DITHER",		 			gl_dither,						"OnOff"
 	StaticText " "
 	Slider "$GLPREFMNU_PALTONEMAPPOWER",		gl_paltonemap_powtable,			0.2, 3.0, 0.1, 1
 	Option "$GLPREFMNU_PALTONEMAPORDER",		gl_paltonemap_reverselookup,	"LookupOrder"

wadsrc/static/shaders/glsl/present.fp

@@ -8,7 +8,6 @@ uniform float Contrast;
 uniform float Brightness;
 uniform float Saturation;
 uniform int GrayFormula;
-uniform float ColorScale;
 
 vec4 ApplyGamma(vec4 c)
 {
@@ -23,36 +22,7 @@ vec4 ApplyGamma(vec4 c)
 	return vec4(val, c.a);
 }
 
-#define HALFSTEP 1./65.
-float DitherMatrix[64] = float[](
-	 0.0 / 16.0 + HALFSTEP * 1,  8.0 / 16.0 + HALFSTEP * 1,  2.0 / 16.0 + HALFSTEP * 1, 10.0 / 16.0 + HALFSTEP * 1,
-	 0.0 / 16.0 + HALFSTEP * 3,  8.0 / 16.0 + HALFSTEP * 3,  2.0 / 16.0 + HALFSTEP * 3, 10.0 / 16.0 + HALFSTEP * 3,
-	12.0 / 16.0 + HALFSTEP * 1,  4.0 / 16.0 + HALFSTEP * 1, 14.0 / 16.0 + HALFSTEP * 1,  6.0 / 16.0 + HALFSTEP * 1,
-	12.0 / 16.0 + HALFSTEP * 3,  4.0 / 16.0 + HALFSTEP * 3, 14.0 / 16.0 + HALFSTEP * 3,  6.0 / 16.0 + HALFSTEP * 3,
-	 3.0 / 16.0 + HALFSTEP * 1, 11.0 / 16.0 + HALFSTEP * 1,  1.0 / 16.0 + HALFSTEP * 1,  9.0 / 16.0 + HALFSTEP * 1,
-	 3.0 / 16.0 + HALFSTEP * 3, 11.0 / 16.0 + HALFSTEP * 3,  1.0 / 16.0 + HALFSTEP * 3,  9.0 / 16.0 + HALFSTEP * 3,
-	15.0 / 16.0 + HALFSTEP * 1,  7.0 / 16.0 + HALFSTEP * 1, 13.0 / 16.0 + HALFSTEP * 1,  5.0 / 16.0 + HALFSTEP * 1,
-	15.0 / 16.0 + HALFSTEP * 3,  7.0 / 16.0 + HALFSTEP * 3, 13.0 / 16.0 + HALFSTEP * 3,  5.0 / 16.0 + HALFSTEP * 3,
-	 0.0 / 16.0 + HALFSTEP * 4,  8.0 / 16.0 + HALFSTEP * 4,  2.0 / 16.0 + HALFSTEP * 4, 10.0 / 16.0 + HALFSTEP * 4,
-	 0.0 / 16.0 + HALFSTEP * 2,  8.0 / 16.0 + HALFSTEP * 2,  2.0 / 16.0 + HALFSTEP * 2, 10.0 / 16.0 + HALFSTEP * 2,
-	12.0 / 16.0 + HALFSTEP * 4,  4.0 / 16.0 + HALFSTEP * 4, 14.0 / 16.0 + HALFSTEP * 4,  6.0 / 16.0 + HALFSTEP * 4,
-	12.0 / 16.0 + HALFSTEP * 2,  4.0 / 16.0 + HALFSTEP * 2, 14.0 / 16.0 + HALFSTEP * 2,  6.0 / 16.0 + HALFSTEP * 2,
-	 3.0 / 16.0 + HALFSTEP * 4, 11.0 / 16.0 + HALFSTEP * 4,  1.0 / 16.0 + HALFSTEP * 4,  9.0 / 16.0 + HALFSTEP * 4,
-	 3.0 / 16.0 + HALFSTEP * 2, 11.0 / 16.0 + HALFSTEP * 2,  1.0 / 16.0 + HALFSTEP * 2,  9.0 / 16.0 + HALFSTEP * 2,
-	15.0 / 16.0 + HALFSTEP * 4,  7.0 / 16.0 + HALFSTEP * 4, 13.0 / 16.0 + HALFSTEP * 4,  5.0 / 16.0 + HALFSTEP * 4,
-	15.0 / 16.0 + HALFSTEP * 2,  7.0 / 16.0 + HALFSTEP * 2, 13.0 / 16.0 + HALFSTEP * 2,  5.0 / 16.0 + HALFSTEP * 2
-);
-
-vec4 Dither(vec4 c)
-{
-	if (ColorScale == 0.0)
-		return c;
-	ivec2 pos = ivec2(gl_FragCoord.xy) & 7;
-	float threshold = DitherMatrix[pos.x + (pos.y << 3)];
-	return vec4(floor(c.rgb * ColorScale + threshold) / ColorScale, c.a);
-}
-
 void main()
 {
-	FragColor = Dither(ApplyGamma(texture(InputTexture, TexCoord)));
+	FragColor = ApplyGamma(texture(InputTexture, TexCoord));
 }