From 91df3f8c73b30065bb3832f181cb001cfda8b9ed Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Wed, 31 Oct 2018 15:56:20 +0100
Subject: [PATCH] - added option to disable alpha testing for user shaders.

---
 src/gl/shaders/gl_shader.cpp            |  2 --
 src/hwrenderer/scene/hw_sprites.cpp     |  6 ++----
 src/hwrenderer/textures/hw_material.cpp |  2 --
 src/r_data/gldefs.cpp                   | 21 +++++++++++++++++----
 src/textures/textures.h                 |  4 ++++
 5 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/src/gl/shaders/gl_shader.cpp b/src/gl/shaders/gl_shader.cpp
index a45b4cf50..d4352dcb7 100644
--- a/src/gl/shaders/gl_shader.cpp
+++ b/src/gl/shaders/gl_shader.cpp
@@ -43,8 +43,6 @@
 #include "gl/renderer/gl_renderer.h"
 #include "gl/shaders/gl_shader.h"
 
-extern TArray<UserShaderDesc> usershaders;
-
 namespace OpenGLRenderer
 {
 
diff --git a/src/hwrenderer/scene/hw_sprites.cpp b/src/hwrenderer/scene/hw_sprites.cpp
index a053ee423..35c492d96 100644
--- a/src/hwrenderer/scene/hw_sprites.cpp
+++ b/src/hwrenderer/scene/hw_sprites.cpp
@@ -104,10 +104,8 @@ void GLSprite::DrawSprite(HWDrawInfo *di, FRenderState &state, bool translucent)
 		{
 			state.AlphaFunc(Alpha_GEqual, 0.f);
 		}
-		else
-		{
-			state.AlphaFunc(Alpha_GEqual, gl_mask_sprite_threshold);
-		}
+		else if (!gltexture->tex->GetTranslucency()) state.AlphaFunc(Alpha_GEqual, gl_mask_sprite_threshold);
+		else state.AlphaFunc(Alpha_Greater, 0.f);
 
 		if (RenderStyle.BlendOp == STYLEOP_Shadow)
 		{
diff --git a/src/hwrenderer/textures/hw_material.cpp b/src/hwrenderer/textures/hw_material.cpp
index 6bd514ccb..48d313d95 100644
--- a/src/hwrenderer/textures/hw_material.cpp
+++ b/src/hwrenderer/textures/hw_material.cpp
@@ -31,8 +31,6 @@
 
 EXTERN_CVAR(Bool, gl_texture_usehires)
 
-extern TArray<UserShaderDesc> usershaders;
-
 //===========================================================================
 // 
 //	Quick'n dirty image rescaling.
diff --git a/src/r_data/gldefs.cpp b/src/r_data/gldefs.cpp
index 62f6f545d..0861a9773 100644
--- a/src/r_data/gldefs.cpp
+++ b/src/r_data/gldefs.cpp
@@ -1154,6 +1154,15 @@ class GLDefsParser
 		tex->bDisableFullbright = disable_fullbright;
 	}
 
+	void SetShaderIndex(FTexture *tex, unsigned index)
+	{
+		auto desc = usershaders[index - FIRST_USER_SHADER];
+		if (desc.disablealphatest)
+		{
+			tex->bTranslucent = true;
+		}
+		tex->shaderindex = index;
+	}
 
 	//==========================================================================
 	//
@@ -1370,11 +1379,11 @@ class GLDefsParser
 					usershaders[i].shaderType == usershader.shaderType &&
 					!usershaders[i].defines.Compare(usershader.defines))
 				{
-					tex->shaderindex = i + FIRST_USER_SHADER;
+					SetShaderIndex(tex, i + FIRST_USER_SHADER);
 					return;
 				}
 			}
-			tex->shaderindex = usershaders.Push(usershader) + FIRST_USER_SHADER;
+			SetShaderIndex(tex, usershaders.Push(usershader) + FIRST_USER_SHADER);
 		}
 	}
 
@@ -1570,6 +1579,10 @@ class GLDefsParser
 					}
 					desc.defines.AppendFormat("#define %s %s\n", defineName.GetChars(), defineValue.GetChars());
 				}
+				else if (sc.Compare("disablealphatest"))
+				{
+					desc.disablealphatest = true;
+				}
 			}
 			if (!tex)
 			{
@@ -1607,11 +1620,11 @@ class GLDefsParser
 						usershaders[i].shaderType == desc.shaderType &&
 						!usershaders[i].defines.Compare(desc.defines))
 					{
-						tex->shaderindex = i + FIRST_USER_SHADER;
+						SetShaderIndex(tex, i + FIRST_USER_SHADER);
 						return;
 					}
 				}
-				tex->shaderindex = usershaders.Push(desc) + FIRST_USER_SHADER;
+				SetShaderIndex(tex, usershaders.Push(desc) + FIRST_USER_SHADER);
 			}
 		}
 	}
diff --git a/src/textures/textures.h b/src/textures/textures.h
index 924614876..e41c7a447 100644
--- a/src/textures/textures.h
+++ b/src/textures/textures.h
@@ -77,8 +77,12 @@ struct UserShaderDesc
 	FString shader;
 	MaterialShaderIndex shaderType;
 	FString defines;
+	bool disablealphatest = false;
 };
 
+extern TArray<UserShaderDesc> usershaders;
+
+
 struct FloatRect
 {
 	float left,top;