From 451c693101b9ca32e3b0bfa654b8fc2dedb73c87 Mon Sep 17 00:00:00 2001
From: Rinnegatamante <rinnegatamante@gmail.com>
Date: Fri, 23 Oct 2020 01:50:16 +0200
Subject: [PATCH] Optimized skinning vertex shader.

---
 src/gl/shaders/skin.vert    | 15 ++++++++-------
 src/gl/shaders/skin_gl3.inc | 15 ++++++++-------
 2 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/src/gl/shaders/skin.vert b/src/gl/shaders/skin.vert
index 982a9e1..4d2ec42 100644
--- a/src/gl/shaders/skin.vert
+++ b/src/gl/shaders/skin.vert
@@ -4,7 +4,7 @@ void main(
 	fixed4 in_color,
 	half2 in_tex0,
 	float4 in_weights,
-	fixed4 in_indices,
+	float4 in_indices,
 	uniform float4x4 u_wvp,
 	uniform float4x4 u_world,
 	uniform half4 u_ambLight,
@@ -20,12 +20,13 @@ void main(
 	fixed out v_fog : FOG,
 	float4 out gl_Position : POSITION
 ) {
-	float3 SkinVertex = float3(0.0, 0.0, 0.0);
-	float3 SkinNormal = float3(0.0, 0.0, 0.0);
-	for(int i = 0; i < 4; i++){
-		SkinVertex += (mul(float4(in_pos, 1.0), u_boneMatrices[int(in_indices[i])])).xyz * in_weights[i];
-		SkinNormal += mul(in_normal, float3x3(u_boneMatrices[int(in_indices[i])])) * in_weights[i];
-	}
+	float4x4 Skin = u_boneMatrices[(int)in_indices.x] * in_weights.x
+		+ u_boneMatrices[(int)in_indices.y] * in_weights.y
+		+ u_boneMatrices[(int)in_indices.z] * in_weights.z
+		+ u_boneMatrices[(int)in_indices.w] * in_weights.w;
+		
+	float3 SkinVertex = (mul(float4(in_pos, 1.f), Skin)).xyz;
+	float3 SkinNormal = (mul(float4(in_normal, 0.f), Skin)).xyz;
 	
 	gl_Position = mul(float4(SkinVertex, 1.0), u_wvp);
 	float3 Normal = mul(SkinNormal, float3x3(u_world));
diff --git a/src/gl/shaders/skin_gl3.inc b/src/gl/shaders/skin_gl3.inc
index d41d848..c8a2038 100644
--- a/src/gl/shaders/skin_gl3.inc
+++ b/src/gl/shaders/skin_gl3.inc
@@ -5,7 +5,7 @@ const char *skin_vert_src =
 "	fixed4 in_color,\n"
 "	half2 in_tex0,\n"
 "	float4 in_weights,\n"
-"	fixed4 in_indices,\n"
+"	float4 in_indices,\n"
 "	uniform float4x4 u_wvp,\n"
 "	uniform float4x4 u_world,\n"
 "	uniform half4 u_ambLight,\n"
@@ -21,12 +21,13 @@ const char *skin_vert_src =
 "	fixed out v_fog : FOG,\n"
 "	float4 out gl_Position : POSITION\n"
 ") {\n"
-"	float3 SkinVertex = float3(0.0, 0.0, 0.0);\n"
-"	float3 SkinNormal = float3(0.0, 0.0, 0.0);\n"
-"	for(int i = 0; i < 4; i++){\n"
-"		SkinVertex += (mul(float4(in_pos, 1.0), u_boneMatrices[int(in_indices[i])])).xyz * in_weights[i];\n"
-"		SkinNormal += mul(in_normal, float3x3(u_boneMatrices[int(in_indices[i])])) * in_weights[i];\n"
-"	}\n"
+"	float4x4 Skin = u_boneMatrices[(int)in_indices.x] * in_weights.x\n"
+"		+ u_boneMatrices[(int)in_indices.y] * in_weights.y\n"
+"		+ u_boneMatrices[(int)in_indices.z] * in_weights.z\n"
+"		+ u_boneMatrices[(int)in_indices.w] * in_weights.w;\n"
+"	\n"	
+"	float3 SkinVertex = (mul(float4(in_pos, 1.f), Skin)).xyz;\n"
+"	float3 SkinNormal = (mul(float4(in_normal, 0.f), Skin)).xyz;\n"
 "	\n"
 "	gl_Position = mul(float4(SkinVertex, 1.0), u_wvp);\n"
 "	float3 Normal = mul(SkinNormal, float3x3(u_world));\n"