From b3e41db14bbe7928885ab7f2028a7773ba0843ec Mon Sep 17 00:00:00 2001
From: Benau <Benau@users.noreply.github.com>
Date: Fri, 30 Nov 2018 23:33:30 +0800
Subject: [PATCH] Add EMT_STK_GRASS for GLES2 to draw grass material without
 vertex color

Now EMT_TRANSPARENT_ALPHA_CHANNEL_REF in GLES2 can be used with vertex
color
---
 .../shaders/irrlicht/COGLES2FixedPipeline.fsh | 24 +++++++++++++++----
 lib/irrlicht/include/EMaterialTypes.h         |  3 +++
 .../source/Irrlicht/COGLES2Driver.cpp         |  2 +-
 .../Irrlicht/COGLES2FixedPipelineRenderer.cpp |  3 +++
 src/graphics/material.cpp                     |  5 ++++
 5 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/data/shaders/irrlicht/COGLES2FixedPipeline.fsh b/data/shaders/irrlicht/COGLES2FixedPipeline.fsh
index f6efdf4e2..09285e7f4 100644
--- a/data/shaders/irrlicht/COGLES2FixedPipeline.fsh
+++ b/data/shaders/irrlicht/COGLES2FixedPipeline.fsh
@@ -12,6 +12,7 @@ precision mediump float;
 #define TransparentAlphaChannelRef 7
 #define TransparentVertexAlpha 8
 #define TransparentReflection2Layer 9
+#define StkGrass 10
 
 /* Uniforms */
 
@@ -101,6 +102,16 @@ vec4 renderTransparent()
 	return Color;
 }
 
+vec4 renderTransparentVertexColor()
+{
+	vec4 Color = varVertexColor;
+
+	if(uTextureUsage0)
+		Color *= texture2D(uTextureUnit0, varTexCoord0);
+
+	return Color;
+}
+
 void main ()
 {
     if (uMaterialType == Solid)
@@ -119,11 +130,16 @@ void main ()
 		gl_FragColor = renderTransparent();
 	else if(uMaterialType == TransparentAlphaChannelRef)
 	{
-		vec4 Color = renderTransparent();
-		
+		vec4 Color = renderTransparentVertexColor();
+		if (Color.a < 0.5)
+			discard;
+		gl_FragColor = Color;
+	}
+	else if(uMaterialType == StkGrass)
+	{
+		vec4 Color = renderTransparent();
 		if (Color.a < 0.5)
 			discard;
-		
 		gl_FragColor = Color;
 	}
 	else if(uMaterialType == TransparentVertexAlpha)
@@ -142,4 +158,4 @@ void main ()
 	}
 	else
 		gl_FragColor = vec4(1.0, 1.0, 1.0, 1.0);
-}
\ No newline at end of file
+}
diff --git a/lib/irrlicht/include/EMaterialTypes.h b/lib/irrlicht/include/EMaterialTypes.h
index 086ca3459..a88f50074 100644
--- a/lib/irrlicht/include/EMaterialTypes.h
+++ b/lib/irrlicht/include/EMaterialTypes.h
@@ -192,6 +192,9 @@ namespace video
 		/** Using only first texture. Generic blending method. */
 		EMT_ONETEXTURE_BLEND,
 
+		//! Alphatest material for grass without using vertex color in stk. */
+		EMT_STK_GRASS,
+
 		//! This value is not used. It only forces this enumeration to compile to 32 bit.
 		EMT_FORCE_32BIT = 0x7fffffff
 	};
diff --git a/lib/irrlicht/source/Irrlicht/COGLES2Driver.cpp b/lib/irrlicht/source/Irrlicht/COGLES2Driver.cpp
index 87b87b73e..b7fa02d28 100644
--- a/lib/irrlicht/source/Irrlicht/COGLES2Driver.cpp
+++ b/lib/irrlicht/source/Irrlicht/COGLES2Driver.cpp
@@ -435,7 +435,7 @@ namespace video
 		addAndDropMaterialRenderer(new COGLES2ParallaxMapRenderer(PMVSData, PMFSData, EMT_PARALLAX_MAP_TRANSPARENT_VERTEX_ALPHA, this));
 
 		addAndDropMaterialRenderer(new COGLES2FixedPipelineRenderer(FPVSData, FPFSData, EMT_ONETEXTURE_BLEND, this));
-		
+		addAndDropMaterialRenderer(new COGLES2FixedPipelineRenderer(FPVSData, FPFSData, EMT_STK_GRASS, this));
 		delete[] FPVSData;
 		delete[] FPFSData;
 		delete[] NMVSData;
diff --git a/lib/irrlicht/source/Irrlicht/COGLES2FixedPipelineRenderer.cpp b/lib/irrlicht/source/Irrlicht/COGLES2FixedPipelineRenderer.cpp
index d1393f437..f7ea1a212 100644
--- a/lib/irrlicht/source/Irrlicht/COGLES2FixedPipelineRenderer.cpp
+++ b/lib/irrlicht/source/Irrlicht/COGLES2FixedPipelineRenderer.cpp
@@ -129,6 +129,9 @@ bool COGLES2FixedPipelineRenderer::OnRender(IMaterialRendererServices* service,
 		case EMT_TRANSPARENT_REFLECTION_2_LAYER:
 			materialType = 9;
 			break;
+		case EMT_STK_GRASS:
+			materialType = 10;
+			break;
 		default:
 			break;
 		}
diff --git a/src/graphics/material.cpp b/src/graphics/material.cpp
index ffde5d9b4..027a5d6a2 100644
--- a/src/graphics/material.cpp
+++ b/src/graphics/material.cpp
@@ -819,6 +819,9 @@ void  Material::setMaterialProperties(video::SMaterial *m, scene::IMeshBuffer* m
     }
     else if (m_shader_name == "grass")
     {
+#ifdef USE_GLES2
+        m->MaterialType = video::EMT_STK_GRASS;
+#else
         m->MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL_REF;
 
 #ifndef SERVER_ONLY
@@ -831,6 +834,8 @@ void  Material::setMaterialProperties(video::SMaterial *m, scene::IMeshBuffer* m
             m->EmissiveColor = video::SColor(255, 150, 150, 150);
             m->SpecularColor = video::SColor(255, 150, 150, 150);
         }
+#endif
+
 #endif
     }