NUKE RGBA16 format handling

This was used for the color buffer in a previous iteration of
overbright.

Author: slipher

src/engine/renderer/tr_image.cpp

@@ -923,18 +923,6 @@ void R_UploadImage( const char *name, const byte **dataArray, int numLayers, int
 		format = GL_DEPTH_STENCIL;
 		internalFormat = GL_DEPTH24_STENCIL8;
 	}
-	else if ( image->bits & IF_RGBA16 )
-	{
-		if ( !glConfig2.textureRGBA16BlendAvailable )
-		{
-			Log::Warn("RGBA16 image '%s' cannot be blended", image->name );
-			internalFormat = GL_RGBA8;
-		}
-		else
-		{
-			internalFormat = GL_RGBA16;
-		}
-	}
 	else if ( image->bits & ( IF_RGBA16F | IF_RGBA32F | IF_TWOCOMP16F | IF_TWOCOMP32F | IF_ONECOMP16F | IF_ONECOMP32F ) )
 	{
 		if( !glConfig2.textureFloatAvailable ) {

src/engine/renderer/tr_init.cpp

@@ -1047,20 +1047,6 @@ ScreenshotCmd screenshotPNGRegistration("screenshotPNG", ssFormat_t::SSF_PNG, "p
 			Log::Notice("%sMissing GPU vertex skinning, models are not hardware-accelerated.", Color::ToString( Color::Red ) );
 		}
 
-		switch ( glConfig2.textureRGBA16BlendAvailable )
-		{
-			case 1:
-				Log::Notice( "%sUsing GL_RGBA16 with GL_FRAMEBUFFER_BLEND.", Color::ToString( Color::Green ) );
-				break;
-			case -1:
-				Log::Notice( "%sUsing GL_RGBA16 with GL_FRAMEBUFFER_BLEND (assumed to be available).", Color::ToString( Color::Yellow ) );
-				break;
-			default:
-			case 0:
-				Log::Notice( "%sMissing GL_RGBA16 with GL_FRAMEBUFFER_BLEND.", Color::ToString( Color::Red ) );
-				break;
-		}
-
 		if ( glConfig.smpActive )
 		{
 			Log::Notice("Using dual processor acceleration." );

src/engine/renderer/tr_local.h

@@ -473,7 +473,6 @@ enum class ssaoMode {
 	  IF_DEPTH32 = BIT( 11 ),
 	  IF_PACKED_DEPTH24_STENCIL8 = BIT( 12 ),
 	  IF_LIGHTMAP = BIT( 13 ),
-	  IF_RGBA16 = BIT( 14 ),
 	  IF_RGBE = BIT( 15 ),
 	  IF_ALPHATEST = BIT( 16 ), // FIXME: this is unused
 	  IF_ALPHA = BIT( 17 ),

src/engine/renderer/tr_public.h

@@ -87,10 +87,8 @@ struct glconfig2_t
 	int maxTexIndirections;
 
 	bool drawBuffersAvailable;
-	bool internalFormatQuery2Available;
 	bool textureHalfFloatAvailable;
 	bool textureFloatAvailable;
-	int textureRGBA16BlendAvailable;
 	bool textureIntegerAvailable;
 	bool textureRGAvailable;
 	bool computeShaderAvailable;

src/engine/sys/sdl_glimp.cpp

@@ -135,10 +135,6 @@ static Cvar::Cvar<bool> workaround_glDriver_amd_oglp_disableBindlessTexture(
 	"workaround.glDriver.amd.oglp.disableBindlessTexture",
 	"Disable ARB_bindless_texture on AMD OGLP driver",
 	Cvar::NONE, true );
-static Cvar::Cvar<bool> workaround_glDriver_mesa_ati_rv300_disableRgba16Blend(
-	"workaround.glDriver.mesa.ati.rv300.disableRgba16Blend",
-	"Disable misdetected RGBA16 on Mesa driver on RV300 hardware",
-	Cvar::NONE, true );
 static Cvar::Cvar<bool> workaround_glDriver_mesa_ati_rv300_useFloatVertex(
 	"workaround.glDriver.mesa.ati.rv300.useFloatVertex",
 	"Use float vertex instead of supported-but-slower half-float vertex on Mesa driver on ATI RV300 hardware",
@@ -2108,75 +2104,6 @@ static void GLimp_InitExtensions()
 	// made required in OpenGL 3.0
 	glConfig2.textureFloatAvailable = LOAD_EXTENSION_WITH_TEST( ExtFlag_CORE, ARB_texture_float, r_ext_texture_float.Get() );
 
-	glConfig2.internalFormatQuery2Available = LOAD_EXTENSION_WITH_TEST( ExtFlag_NONE, ARB_internalformat_query2, r_arb_internalformat_query2.Get() );
-
-	if ( glConfig2.internalFormatQuery2Available )
-	{
-		GLint64 param;
-		glGetInternalformati64v( GL_TEXTURE_2D, GL_RGBA16, GL_FRAMEBUFFER_BLEND, 1, &param );
-
-		if ( param == GL_FULL_SUPPORT || param == GL_TRUE )
-		{
-			/* There is a discrepancy between OpenGL specification and OpenGL reference pages.
-
-			The OpenGL 4.3 Core specification says the query should return either GL_FULL_SUPPORT,
-			GL_CAVEAT_SUPPORT, or GL_NONE:
-
-			- https://registry.khronos.org/OpenGL/specs/gl/glspec43.core.pdf#page=517
-
-			The ARB_internalformat_query2 document says the same:
-
-			- https://registry.khronos.org/OpenGL/extensions/ARB/ARB_internalformat_query2.txt
-
-			The OpenGL wiki page for glGetInternalformat says the same:
-
-			- https://www.khronos.org/opengl/wiki/GLAPI/glGetInternalformat
-
-			But the glGetInternalformat reference page says the query should return GL_TRUE
-			or GL_FALSE:
-
-			- https://registry.khronos.org/OpenGL-Refpages/gl4/html/glGetInternalformat.xhtml
-
-			The meaning of GL_CAVEAT_SUPPORT as a return of a GL_FRAMEBUFFER_BLEND query is
-			unknown. See this thread for details:
-
-			- https://github.com/KhronosGroup/OpenGL-Refpages/issues/157
-
-			Because of this discrepancy in documentation, drivers may have implemented
-			either GL_FULL_SUPPORT or GL_TRUE as a return for feature availability. */
-			glConfig2.textureRGBA16BlendAvailable = 1;
-		}
-		else if ( param == GL_CAVEAT_SUPPORT || param == GL_NONE )
-		{
-			/* Older Mesa versions were mistakenly reporting full support for every driver on
-			every hardware. A return that is not GL_FULL_SUPPORT and not GL_TRUE is the only
-			value we can trust. See those threads for details:
-
-			- https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30612
-			- https://gitlab.freedesktop.org/mesa/mesa/-/issues/11669#note_2521403
-
-			GL_FALSE has same value as GL_NONE. */
-			glConfig2.textureRGBA16BlendAvailable = 0;
-		}
-	}
-	else
-	{
-		/* Assume this is an old driver without the query extension but the RGBA16 blending is
-		available, as the feature is much older than the extension to check for it, the feature
-		is very likely supported. */
-		glConfig2.textureRGBA16BlendAvailable = -1;
-	}
-
-	/* Workaround for drivers not implementing the feature query or wrongly reporting the feature
-	to be supported, for various reasons. */
-	if ( workaround_glDriver_mesa_ati_rv300_disableRgba16Blend.Get() )
-	{
-		if ( glConfig2.textureRGBA16BlendAvailable != 0 && glConfig.hardwareType == glHardwareType_t::GLHW_R300 )
-		{
-			glConfig2.textureRGBA16BlendAvailable = 0;
-		}
-	}
-
 	bool gpuShader4Enabled = r_ext_gpu_shader4.Get();
 
 	if ( gpuShader4Enabled
@@ -2708,7 +2635,6 @@ bool GLimp_Init()
 
 	Cvar::Latch( workaround_glDriver_amd_adrenalin_disableBindlessTexture );
 	Cvar::Latch( workaround_glDriver_amd_oglp_disableBindlessTexture );
-	Cvar::Latch( workaround_glDriver_mesa_ati_rv300_disableRgba16Blend );
 	Cvar::Latch( workaround_glDriver_mesa_ati_rv300_useFloatVertex );
 	Cvar::Latch( workaround_glDriver_mesa_ati_rv600_disableHyperZ );
 	Cvar::Latch( workaround_glDriver_mesa_broadcom_vc4_useFloatVertex );