Fixes post shadows compilation issue on android

Author: Nehon

jme3-core/src/main/java/com/jme3/renderer/opengl/GLRenderer.java

@@ -1327,6 +1327,7 @@ public void updateShaderSourceData(ShaderSource source) {
                     + "Only GLSL 1.00 shaders are supported.");
         }
 
+        boolean insertPrecision = false;
         // Upload shader source.
         // Merge the defines and source code.
         stringBuf.setLength(0);
@@ -1346,7 +1347,7 @@ public void updateShaderSourceData(ShaderSource source) {
 
                     if (source.getType() == ShaderType.Fragment) {
                         // GLES2 requires precision qualifier.
-                        stringBuf.append("precision mediump float;\n");
+                        insertPrecision = true;
                     }
                 } else {
                     // version 100 does not exist in desktop GLSL.
@@ -1365,6 +1366,14 @@ public void updateShaderSourceData(ShaderSource source) {
         stringBuf.append(source.getDefines());
         stringBuf.append(source.getSource());
 
+        if(insertPrecision){
+            // precision token is not a preprocessor dirrective therefore it must be placed after #extension tokens to avoid
+            // Error P0001: Extension directive must occur before any non-preprocessor tokens
+            int idx = stringBuf.lastIndexOf("#extension");
+            idx = stringBuf.indexOf("\n", idx);
+            stringBuf.insert(idx + 1, "precision mediump float;\n");
+        }
+
         intBuf1.clear();
         intBuf1.put(0, stringBuf.length());
         gl.glShaderSource(id, new String[]{ stringBuf.toString() }, intBuf1);

jme3-core/src/main/resources/Common/ShaderLib/Shadows.glsllib

@@ -3,7 +3,10 @@
     // gather functions are declared to work on shadowmaps
     #extension GL_ARB_gpu_shader5 : enable
     #define IVEC2 ivec2
-    #ifdef HARDWARE_SHADOWS
+    #if defined GL_ES
+        #define SHADOWMAP sampler2D
+        #define SHADOWCOMPARE(tex,coord) step(coord.z, texture2DProj(tex, coord).r)
+    #elif defined HARDWARE_SHADOWS
         #define SHADOWMAP sampler2DShadow
         #define SHADOWCOMPAREOFFSET(tex,coord,offset) textureProjOffset(tex, coord, offset)
         #define SHADOWCOMPARE(tex,coord) textureProj(tex, coord)

jme3-examples/src/main/java/jme3test/light/TestShadowsPerf.java

@@ -69,7 +69,6 @@ public static void main(String[] args) {
 
     @Override
     public void simpleInitApp() {
-        Logger.getLogger("com.jme3").setLevel(Level.SEVERE);
         flyCam.setMoveSpeed(50);
         flyCam.setEnabled(false);
         viewPort.setBackgroundColor(ColorRGBA.DarkGray);