From fe23c1619897eb357e2f064a1cafe4f5f8926ef9 Mon Sep 17 00:00:00 2001
From: Alex Szpakowski <slime73@gmail.com>
Date: Thu, 24 Dec 2020 20:31:33 -0400
Subject: [PATCH] Disable gamma correction on Windows + Intel HD 2/3000  /
 Intel HD Graphics

It's completely broken there. Closes #1592
---
 src/modules/graphics/opengl/Canvas.cpp   |  9 ---------
 src/modules/graphics/opengl/Graphics.cpp |  4 ++--
 src/modules/graphics/opengl/OpenGL.cpp   | 16 ++++++++++++++--
 src/modules/graphics/opengl/OpenGL.h     |  7 +++++++
 4 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/src/modules/graphics/opengl/Canvas.cpp b/src/modules/graphics/opengl/Canvas.cpp
index 9bd14ab51..9a38c0305 100644
--- a/src/modules/graphics/opengl/Canvas.cpp
+++ b/src/modules/graphics/opengl/Canvas.cpp
@@ -39,11 +39,6 @@ static GLenum createFBO(GLuint &framebuffer, TextureType texType, PixelFormat fo
 	glGenFramebuffers(1, &framebuffer);
 	gl.bindFramebuffer(OpenGL::FRAMEBUFFER_ALL, framebuffer);
 
-	// Might work around an Intel driver bug: https://github.com/love2d/love/issues/1592
-	bool current_srgb = gl.isStateEnabled(OpenGL::ENABLE_FRAMEBUFFER_SRGB);
-	if (current_srgb && isPixelFormatDepthStencil(format))
-		gl.setEnableState(OpenGL::ENABLE_FRAMEBUFFER_SRGB, false);
-
 	if (texture != 0)
 	{
 		if (isPixelFormatDepthStencil(format) && (GLAD_ES_VERSION_3_0 || !GLAD_ES_VERSION_2_0))
@@ -110,10 +105,6 @@ static GLenum createFBO(GLuint &framebuffer, TextureType texType, PixelFormat fo
 
 	gl.bindFramebuffer(OpenGL::FRAMEBUFFER_ALL, current_fbo);
 
-	// Restore sRGB state if we turned it off above.
-	if (current_srgb && isPixelFormatDepthStencil(format))
-		gl.setEnableState(OpenGL::ENABLE_FRAMEBUFFER_SRGB, current_srgb);
-
 	return status;
 }
 
diff --git a/src/modules/graphics/opengl/Graphics.cpp b/src/modules/graphics/opengl/Graphics.cpp
index 6b5e229be..d826479ee 100644
--- a/src/modules/graphics/opengl/Graphics.cpp
+++ b/src/modules/graphics/opengl/Graphics.cpp
@@ -198,8 +198,8 @@ bool Graphics::setMode(int width, int height, int pixelwidth, int pixelheight, b
 		glEnable(GL_TEXTURE_CUBE_MAP_SEAMLESS);
 
 	// Set whether drawing converts input from linear -> sRGB colorspace.
-	if (GLAD_VERSION_3_0 || GLAD_ARB_framebuffer_sRGB || GLAD_EXT_framebuffer_sRGB
-		|| GLAD_ES_VERSION_3_0 || GLAD_EXT_sRGB)
+	if (!gl.bugs.brokenSRGB && (GLAD_VERSION_3_0 || GLAD_ARB_framebuffer_sRGB
+		|| GLAD_EXT_framebuffer_sRGB || GLAD_ES_VERSION_3_0 || GLAD_EXT_sRGB))
 	{
 		if (GLAD_VERSION_1_0 || GLAD_EXT_sRGB_write_control)
 			gl.setEnableState(OpenGL::ENABLE_FRAMEBUFFER_SRGB, isGammaCorrect());
diff --git a/src/modules/graphics/opengl/OpenGL.cpp b/src/modules/graphics/opengl/OpenGL.cpp
index 44d7f8767..a5757798f 100644
--- a/src/modules/graphics/opengl/OpenGL.cpp
+++ b/src/modules/graphics/opengl/OpenGL.cpp
@@ -155,6 +155,16 @@ bool OpenGL::initContext()
 		if (strstr(device, "HD Graphics 4000") || strstr(device, "HD Graphics 2500"))
 			bugs.clientWaitSyncStalls = true;
 	}
+
+	if (getVendor() == VENDOR_INTEL)
+	{
+		const char *device = (const char *) glGetString(GL_RENDERER);
+		if (strstr(device, "HD Graphics 3000") || strstr(device, "HD Graphics 2000")
+			|| !strcmp(device, "Intel(R) HD Graphics") || !strcmp(device, "Intel(R) HD Graphics Family"))
+		{
+			bugs.brokenSRGB = true;
+		}
+	}
 #endif
 
 #ifdef LOVE_WINDOWS
@@ -215,8 +225,8 @@ void OpenGL::setupContext()
 	setEnableState(ENABLE_SCISSOR_TEST, state.enableState[ENABLE_SCISSOR_TEST]);
 	setEnableState(ENABLE_FACE_CULL, state.enableState[ENABLE_FACE_CULL]);
 
-	if (GLAD_VERSION_3_0 || GLAD_ARB_framebuffer_sRGB || GLAD_EXT_framebuffer_sRGB
-		|| GLAD_EXT_sRGB_write_control)
+	if (!bugs.brokenSRGB && (GLAD_VERSION_3_0 || GLAD_ARB_framebuffer_sRGB
+		|| GLAD_EXT_framebuffer_sRGB || GLAD_EXT_sRGB_write_control))
 	{
 		setEnableState(ENABLE_FRAMEBUFFER_SRGB, state.enableState[ENABLE_FRAMEBUFFER_SRGB]);
 	}
@@ -1717,6 +1727,8 @@ bool OpenGL::isPixelFormatSupported(PixelFormat pixelformat, bool rendertarget,
 		else
 			return true;
 	case PIXELFORMAT_sRGBA8:
+		if (gl.bugs.brokenSRGB)
+			return false;
 		if (rendertarget)
 		{
 			if (GLAD_VERSION_1_0)
diff --git a/src/modules/graphics/opengl/OpenGL.h b/src/modules/graphics/opengl/OpenGL.h
index a1a6cb61a..a2467ad25 100644
--- a/src/modules/graphics/opengl/OpenGL.h
+++ b/src/modules/graphics/opengl/OpenGL.h
@@ -177,6 +177,13 @@ public:
 		 **/
 		bool brokenR8PixelFormat;
 
+		/**
+		 * Intel HD Graphics drivers on Windows prior to the HD 2500/4000 have
+		 * completely broken sRGB support.
+		 * https://github.com/love2d/love/issues/1592
+		 **/
+		bool brokenSRGB;
+
 		/**
 		 * Other bugs which have workarounds that don't use conditional code at
 		 * the moment: