Improves OpenGL-ES support (especially for Raspberry Pi), contribution of Erkki Nokso-Koivisto

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@10269 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/jogl/com/jme3/renderer/jogl/JoglRenderer.java

@@ -2277,7 +2277,7 @@ public class JoglRenderer implements Renderer {
         assert bufId != -1;
 
         GL gl = GLContext.getCurrentGL();
-        if (gl.isGL2GL3()) {
+
         if (context.boundElementArrayVBO != bufId) {
             gl.glBindBuffer(GL.GL_ELEMENT_ARRAY_BUFFER, bufId);
             context.boundElementArrayVBO = bufId;
@@ -2309,7 +2309,7 @@ public class JoglRenderer implements Renderer {
                 int elementLength = elementLengths[i];
 
                 if (useInstancing) {
-
+                    if (gl.isGL2GL3()) {
                         indexBuf.getData().position(curOffset);
                         indexBuf.getData().limit(curOffset + elementLength);
 
@@ -2318,43 +2318,63 @@ public class JoglRenderer implements Renderer {
                                 fmt,
                                 indexBuf.getData(),
                                 count);
-
                     } else {
+                        throw new IllegalArgumentException(
+                                "instancing is not supported.");
+                    }
+                } else {
+                    if (gl.isGL2GL3()) {
                         gl.getGL2GL3().glDrawRangeElements(elMode,
                                 0,
                                 vertCount,
                                 elementLength,
                                 fmt,
                                 curOffset);
+                    } else {
+                        indexBuf.getData().position(curOffset);
+                        gl.glDrawElements(elMode, elementLength, fmt,
+                                indexBuf.getData());
+                    }
                 }
 
                 //FIXME check whether elSize is required
-                    curOffset += elementLength/* * elSize*/;
+                curOffset += elementLength * elSize;
             }
         } else {
             if (useInstancing) {
+                if (gl.isGL2GL3()) {
                     gl.getGL2GL3().glDrawElementsInstanced(convertElementMode(mesh.getMode()),
                             indexBuf.getData().limit(),
                             convertFormat(indexBuf.getFormat()),
                             indexBuf.getData(),
                             count);
                 } else {
+                    throw new IllegalArgumentException(
+                            "instancing is not supported.");
+                }
+            } else {
+                if (gl.isGL2GL3()) {
                     gl.getGL2GL3().glDrawRangeElements(convertElementMode(mesh.getMode()),
                             0,
                             vertCount,
                             indexBuf.getData().limit(),
                             convertFormat(indexBuf.getFormat()),
                             0);
+                } else {
+                    indexBuf.getData().rewind();
+                    gl.glDrawElements(convertElementMode(mesh.getMode()),
+                            indexBuf.getData().limit(),
+                            convertFormat(indexBuf.getFormat()), 0);
                 }
             }
-        } else {
-            //FIXME: ES impl
         }
     }
 
-    /*********************************************************************\
+    /**
-    |* Render Calls                                                      *|
+     * *******************************************************************\ |*
-    \*********************************************************************/
+     * Render Calls *|
+    \********************************************************************
+     */
     private int convertElementMode(Mesh.Mode mode) {
         switch (mode) {
             case Points:
@@ -2379,10 +2399,7 @@ public class JoglRenderer implements Renderer {
     public void updateVertexArray(Mesh mesh) {
         int id = mesh.getId();
         GL gl = GLContext.getCurrentGL();
-        //FIXME rather use GLCaps and do it once for all
+
-        boolean isVaoSupported = gl.isFunctionAvailable("glGenVertexArrays") && 
-                gl.isFunctionAvailable("glBindVertexArray");
-        if (isVaoSupported) {
         if (id == -1) {
             IntBuffer temp = intBuf1;
             if (gl.isGL2GL3()) {
@@ -2398,7 +2415,6 @@ public class JoglRenderer implements Renderer {
             }
             context.boundVertexArray = id;
         }
-        }
 
         VertexBuffer interleavedData = mesh.getBuffer(Type.InterleavedData);
         if (interleavedData != null && interleavedData.isUpdateNeeded()) {