PreShadow & PostShadow Support for PBRLighting.j3md (#1265)

* Update PBRLighting.j3md

* Create PreShadowPBR.frag

* Create PostShadowPBR.frag

jme3-core/src/main/resources/Common/MatDefs/Light/PBRLighting.j3md

@@ -168,7 +168,7 @@ MaterialDef PBR Lighting {
     Technique PreShadow {
 
         VertexShader GLSL300 GLSL100 GLSL150 :   Common/MatDefs/Shadow/PreShadow.vert
-        FragmentShader GLSL300 GLSL100 GLSL150 : Common/MatDefs/Shadow/PreShadow.frag
+        FragmentShader GLSL300 GLSL100 GLSL150 : Common/MatDefs/Shadow/PreShadowPBR.frag
 
         WorldParameters {
             WorldViewProjectionMatrix
@@ -198,7 +198,7 @@ MaterialDef PBR Lighting {
 
     Technique PostShadow{
         VertexShader GLSL310 GLSL300 GLSL150:   Common/MatDefs/Shadow/PostShadow.vert
-        FragmentShader GLSL310 GLSL300 GLSL150: Common/MatDefs/Shadow/PostShadow.frag
+        FragmentShader GLSL310 GLSL300 GLSL150: Common/MatDefs/Shadow/PostShadowPBR.frag
 
         WorldParameters {
             WorldViewProjectionMatrix
@@ -233,7 +233,7 @@ MaterialDef PBR Lighting {
 
     Technique PostShadow{
         VertexShader GLSL100:   Common/MatDefs/Shadow/PostShadow.vert
-        FragmentShader GLSL100: Common/MatDefs/Shadow/PostShadow.frag
+        FragmentShader GLSL100: Common/MatDefs/Shadow/PostShadowPBR.frag
 
         WorldParameters {
             WorldViewProjectionMatrix

jme3-core/src/main/resources/Common/MatDefs/Shadow/PostShadowPBR.frag

@@ -0,0 +1,89 @@
+  
+#import "Common/ShaderLib/GLSLCompat.glsllib"
+#import "Common/ShaderLib/Shadows.glsllib"
+#if defined(PSSM) || defined(FADE)
+varying float shadowPosition;
+#endif
+
+varying vec4 projCoord0;
+varying vec4 projCoord1;
+varying vec4 projCoord2;
+varying vec4 projCoord3;
+#ifndef BACKFACE_SHADOWS
+    varying float nDotL;
+#endif
+
+#ifdef POINTLIGHT
+    varying vec4 projCoord4;
+    varying vec4 projCoord5;
+    uniform vec3 m_LightPos;
+    varying vec4 worldPos;
+#else
+    #ifndef PSSM        
+        varying float lightDot;
+    #endif
+#endif
+
+#ifdef DISCARD_ALPHA
+    #ifdef COLOR_MAP
+        uniform sampler2D m_ColorMap;
+    #else    
+        uniform sampler2D m_BaseColorMap;
+    #endif
+    uniform float m_AlphaDiscardThreshold;
+    varying vec2 texCoord;
+#endif
+
+#ifdef FADE
+uniform vec2 m_FadeInfo;
+#endif
+
+void main(){   
+ 
+    #ifdef DISCARD_ALPHA
+        #ifdef COLOR_MAP
+            float alpha = texture2D(m_ColorMap,texCoord).a;
+        #else    
+            float alpha = texture2D(m_BaseColorMap,texCoord).a;
+        #endif
+        if(alpha<=m_AlphaDiscardThreshold){
+            discard;
+        }
+    #endif
+
+    #ifndef BACKFACE_SHADOWS
+        if(nDotL > 0.0){
+            discard;
+        }
+    #endif
+
+
+    float shadow = 1.0;
+ 
+    #ifdef POINTLIGHT         
+            shadow = getPointLightShadows(worldPos, m_LightPos,
+                           m_ShadowMap0,m_ShadowMap1,m_ShadowMap2,m_ShadowMap3,m_ShadowMap4,m_ShadowMap5,
+                           projCoord0, projCoord1, projCoord2, projCoord3, projCoord4, projCoord5);
+    #else
+       #ifdef PSSM
+            shadow = getDirectionalLightShadows(m_Splits, shadowPosition,
+                           m_ShadowMap0,m_ShadowMap1,m_ShadowMap2,m_ShadowMap3,
+                           projCoord0, projCoord1, projCoord2, projCoord3);
+       #else 
+            //spotlight
+            if(lightDot < 0.0){
+                gl_FragColor = vec4(1.0);
+                return;
+            }
+            shadow = getSpotLightShadows(m_ShadowMap0,projCoord0);
+       #endif
+    #endif   
+
+    #ifdef FADE
+        shadow = max(0.0, mix(shadow, 1.0, max(0.0, (shadowPosition - m_FadeInfo.x) * m_FadeInfo.y)));
+    #endif
+
+    shadow = shadow * m_ShadowIntensity + (1.0 - m_ShadowIntensity);
+    gl_FragColor = vec4(shadow, shadow, shadow, 1.0);
+
+}

jme3-core/src/main/resources/Common/MatDefs/Shadow/PreShadowPBR.frag

@@ -0,0 +1,28 @@
+#import "Common/ShaderLib/GLSLCompat.glsllib"
+varying vec2 texCoord;
+
+#ifdef DISCARD_ALPHA
+   #ifdef COLOR_MAP
+      uniform sampler2D m_ColorMap;
+   #else    
+      uniform sampler2D m_BaseColorMap;
+   #endif
+    uniform float m_AlphaDiscardThreshold;
+#endif
+
+
+void main(){
+   #ifdef DISCARD_ALPHA
+       #ifdef COLOR_MAP
+            if (texture2D(m_ColorMap, texCoord).a <= m_AlphaDiscardThreshold){
+                discard;
+            }
+       #else    
+            if (texture2D(m_BaseColorMap, texCoord).a <= m_AlphaDiscardThreshold){
+                discard;
+            }
+       #endif
+   #endif
+
+   gl_FragColor = vec4(1.0);
+}