GLRenderer.modifyTexture on GLES fix (#1235)

* Update GLImageFormats.java

* First implementation to solve the glTexSubImage issue

* Setting proper format to the image

* Removed the Image.convertToFormat method and its usage from GLRenderer.modifyTexture. Added a warning instead for the potential failing cases
Fixing the issue in JmeBatchRenderBackend.loadImage transforming it to RGBA8 if required

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

@@ -2549,6 +2549,9 @@ public final class GLRenderer implements Renderer {
     @Deprecated
     public void modifyTexture(Texture tex, Image pixels, int x, int y) {
         setTexture(0, tex);
+        if(caps.contains(Caps.OpenGLES20) && pixels.getFormat()!=tex.getImage().getFormat() ) {
+            logger.log(Level.WARNING, "Incompatible texture subimage");
+        }
         int target = convertTextureType(tex.getType(), pixels.getMultiSamples(), -1);
         texUtil.uploadSubTexture(target,pixels, 0, x, y,0,0,pixels.getWidth(),pixels.getHeight(), linearizeSrgbImages);     
     }
@@ -2566,6 +2569,9 @@ public final class GLRenderer implements Renderer {
      */
     public void modifyTexture(Texture2D dest, Image src, int destX, int destY, int srcX, int srcY, int areaW, int areaH) {
         setTexture(0, dest);
+        if(caps.contains(Caps.OpenGLES20) && src.getFormat()!=dest.getImage().getFormat() ) {
+            logger.log(Level.WARNING, "Incompatible texture subimage");
+        }
         int target = convertTextureType(dest.getType(), src.getMultiSamples(), -1);
         texUtil.uploadSubTexture(target, src, 0, destX, destY, srcX, srcY, areaW, areaH, linearizeSrgbImages);
     }

jme3-niftygui/src/main/java/com/jme3/niftygui/JmeBatchRenderBackend.java

@@ -43,7 +43,9 @@ import java.util.logging.Logger;
 import com.jme3.asset.TextureKey;
 import com.jme3.material.Material;
 import com.jme3.material.RenderState;
+import com.jme3.math.ColorRGBA;
 import com.jme3.math.Matrix4f;
+import com.jme3.renderer.Caps;
 import com.jme3.renderer.RenderManager;
 import com.jme3.renderer.Renderer;
 import com.jme3.scene.Geometry;
@@ -52,6 +54,7 @@ import com.jme3.scene.VertexBuffer;
 import com.jme3.scene.VertexBuffer.Type;
 import com.jme3.scene.VertexBuffer.Usage;
 import com.jme3.texture.Image.Format;
+import com.jme3.texture.image.ImageRaster;
 import com.jme3.texture.Texture.MagFilter;
 import com.jme3.texture.Texture.MinFilter;
 import com.jme3.texture.Texture2D;
@@ -214,6 +217,31 @@ public class JmeBatchRenderBackend implements BatchRenderBackend {
     key.setGenerateMips(false);
 
     Texture2D texture = (Texture2D) display.getAssetManager().loadTexture(key);
+    // Fix GLES format incompatibility issue with glTexSubImage 
+    Renderer renderer = display.getRenderer();
+    if(renderer==null || renderer.getCaps().contains(Caps.OpenGLES20)) {
+        if(texture.getImage().getFormat()!=Format.RGBA8) {
+            com.jme3.texture.Image sourceImage = texture.getImage();
+            int size = sourceImage.getWidth() * sourceImage.getHeight() * 4;
+            ByteBuffer buffer = BufferUtils.createByteBuffer(size);
+            com.jme3.texture.Image rgba8Image = new com.jme3.texture.Image(Format.RGBA8,
+                                         sourceImage.getWidth(),
+                                         sourceImage.getHeight(),
+                                         buffer,
+                                         sourceImage.getColorSpace());
+            
+            ImageRaster input = ImageRaster.create(sourceImage, 0, 0, false);
+            ImageRaster output = ImageRaster.create(rgba8Image, 0, 0, false);
+            ColorRGBA color = new ColorRGBA();
+
+            for (int y = 0; y < sourceImage.getHeight(); y++) {
+                for (int x = 0; x < sourceImage.getWidth(); x++) {
+                    output.setPixel(x, y, input.getPixel(x, y, color));
+                }
+            }
+            return new ImageImpl(rgba8Image);
+        }
+    }
     return new ImageImpl(texture.getImage());
   }