From e5a37a70232f43cd6bd3b76afcb26d0053fe56b5 Mon Sep 17 00:00:00 2001
From: scrawl <scrawl@baseoftrash.de>
Date: Thu, 18 Feb 2016 00:00:12 +0100
Subject: [PATCH] Add normal map code

---
 files/shaders/objects_fragment.glsl | 20 ++++++++++++++++++--
 files/shaders/objects_vertex.glsl   | 12 +++++++++++-
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/files/shaders/objects_fragment.glsl b/files/shaders/objects_fragment.glsl
index f3a9aa766..6346aa499 100644
--- a/files/shaders/objects_fragment.glsl
+++ b/files/shaders/objects_fragment.glsl
@@ -20,9 +20,15 @@ uniform sampler2D emissiveMap;
 varying vec2 emissiveMapUV;
 #endif
 
+#if @normalMap
+uniform sampler2D normalMap;
+varying vec2 normalMapUV;
+varying vec3 viewTangent;
+#endif
+
 varying float depth;
 
-#define PER_PIXEL_LIGHTING 0
+#define PER_PIXEL_LIGHTING @normalMap
 
 #if !PER_PIXEL_LIGHTING
 varying vec4 lighting;
@@ -50,11 +56,21 @@ void main()
     gl_FragData[0].xyz *= texture2D(darkMap, darkMapUV).xyz;
 #endif
 
+#if @normalMap
+    vec3 viewNormal = passViewNormal;
+    vec3 normalTex = texture2D(normalMap, normalMapUV).xyz;
+
+    vec3 viewBinormal = cross(viewTangent, viewNormal);
+    mat3 tbn = mat3(viewTangent, viewBinormal, viewNormal);
+
+    viewNormal = normalize(tbn * (normalTex * 2.0 - 1.0));
+#endif
+
 
 #if !PER_PIXEL_LIGHTING
     gl_FragData[0] *= lighting;
 #else
-    gl_FragData[0] *= doLighting(passViewPos, passViewNormal, passColour);
+    gl_FragData[0] *= doLighting(passViewPos, normalize(viewNormal), passColour);
 #endif
 
 #if @emissiveMap
diff --git a/files/shaders/objects_vertex.glsl b/files/shaders/objects_vertex.glsl
index 7a6f0ca21..08fdb4ef8 100644
--- a/files/shaders/objects_vertex.glsl
+++ b/files/shaders/objects_vertex.glsl
@@ -16,9 +16,14 @@ varying vec2 detailMapUV;
 varying vec2 emissiveMapUV;
 #endif
 
+#if @normalMap
+varying vec2 normalMapUV;
+varying vec3 viewTangent;
+#endif
+
 varying float depth;
 
-#define PER_PIXEL_LIGHTING 0
+#define PER_PIXEL_LIGHTING @normalMap
 
 #if !PER_PIXEL_LIGHTING
 varying vec4 lighting;
@@ -55,6 +60,11 @@ void main(void)
     emissiveMapUV = (gl_TextureMatrix[@emissiveMapUV] * gl_MultiTexCoord@emissiveMapUV).xy;
 #endif
 
+#if @normalMap
+    normalMapUV = (gl_TextureMatrix[@normalMapUV] * gl_MultiTexCoord@normalMapUV).xy;
+    viewTangent = normalize(gl_NormalMatrix * gl_MultiTexCoord7.xyz);
+#endif
+
 #if !PER_PIXEL_LIGHTING
     lighting = doLighting(viewPos.xyz, viewNormal, gl_Color);
 #else