HW Skinning

* Added check in shader for number of bones
 * Fix crash when Skinning.glsllib is imported by shader 
 * Fix incorrect transform of tangent vector in shader 

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@10552 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/core-data/Common/ShaderLib/Skinning.glsllib

@@ -1,5 +1,11 @@
 #ifdef NUM_BONES
 
+#if NUM_BONES < 1 || NUM_BONES > 255
+#error NUM_BONES must be between 1 and 255.
+#endif
+
+#define NUM_WEIGHTS_PER_VERT 4
+ 
 attribute vec4 inBoneWeight;
 attribute vec4 inBoneIndex;
 uniform mat4 m_BoneMatrices[NUM_BONES];
@@ -30,11 +36,13 @@ void Skinning_Compute(inout vec4 position, inout vec3 normal){
     mat += m_BoneMatrices[int(inBoneIndex.z)] * inBoneWeight.z;
     mat += m_BoneMatrices[int(inBoneIndex.w)] * inBoneWeight.w;
     position = mat * position;
-    normal = (mat3(mat[0].xyz,mat[1].xyz,mat[2].xyz) * normal);
+
+    mat3 rotMat = mat3(mat[0].xyz, mat[1].xyz, mat[2].xyz);
+    normal = rotMat * normal;
 #endif
 }
  
-void Skinning_Compute(inout vec4 position, inout vec4 tangent, inout vec3 normal){
+void Skinning_Compute(inout vec4 position, inout vec3 tangent, inout vec3 normal){
 #if NUM_WEIGHTS_PER_VERT == 1
     position = m_BoneMatrices[int(inBoneIndex.x)] * position;
     tangent = m_BoneMatrices[int(inBoneIndex.x)] * tangent;
@@ -48,8 +56,11 @@ void Skinning_Compute(inout vec4 position, inout vec4 tangent, inout vec3 normal
     mat += m_BoneMatrices[int(inBoneIndex.z)] * inBoneWeight.z;
     mat += m_BoneMatrices[int(inBoneIndex.w)] * inBoneWeight.w;
     position = mat * position;
-    tangent = mat * tangent;
+
-    normal = (mat3(mat[0].xyz,mat[1].xyz,mat[2].xyz) * normal);
+    mat3 rotMat = mat3(mat[0].xyz, mat[1].xyz, mat[2].xyz);
+    tangent = rotMat * tangent;
+    normal = rotMat * normal;
 #endif
 }
+
 #endif