partial followup to #202.

largely cleanups, though does include glCopyImageSubData for gl revs that support it
TODOS:
1) non glCopyImageSubData for `void GFXGLCubemapArray::copyTo(GFXCubemapArray *pDstCubemap)`
2) while we don't get corruption showing in >0 mips for irradiance maps using the newer code, it nevertheless renders wrong.
not 100% sure if renderdoc is showing blank mips because it expects it due to size, or if we are in fact generating em even though we don't use em in the end for irradiance references.

Engine/source/gfx/gl/gfxGLCubemap.cpp

@@ -227,7 +227,7 @@ void GFXGLCubemap::initDynamic(U32 texSize, GFXFormat faceFormat, U32 mipLevels)
         }
     }
 
-    if( !isCompressed )
+    if( !isCompressed && !mipLevels)
         glGenerateMipmap(GL_TEXTURE_CUBE_MAP);
     mInitialized = true;
 }

Engine/source/gfx/gl/gfxGLDevice.cpp

@@ -475,28 +475,33 @@ void GFXGLDevice::copyResource(GFXTextureObject* pDst, GFXCubemap* pSrc, const U
 
    const bool isCompressed = ImageUtil::isCompressedFormat(format);
 
-   U32 mipLevels = pGLSrc->getMipMapLevels();
-   if (mipLevels < 1) mipLevels = 1;//ensure we loop at least the once
+   U32 mipLevels = gGLDst->getMipLevels();
    for (U32 mip = 0; mip < mipLevels; mip++)
    {
-      U8* pixelData = pGLSrc->getTextureData(face, mip);
-
-      glBindTexture(gGLDst->getBinding(), gGLDst->getHandle());
       const U32 mipSize = getMax(U32(1), pGLSrc->getSize() >> mip);
-      if (isCompressed)
+      if (GFXGL->mCapabilities.copyImage)
       {
-         const U32 mipDataSize = getCompressedSurfaceSize(format, pGLSrc->getSize(), pGLSrc->getSize(), 0);
-
-         glCompressedTexSubImage2D(gGLDst->getBinding(), mip, 0, 0, mipSize, mipSize, GFXGLTextureFormat[format], mipDataSize, pixelData);
+         glCopyImageSubData(pGLSrc->mCubemap, GL_TEXTURE_CUBE_MAP, mip, 0, 0, face, gGLDst->getHandle(), GL_TEXTURE_2D, mip, 0, 0, 0, mipSize, mipSize, 1);
       }
       else
       {
-         //glCopyImageSubData(pGLSrc->mCubemap, GFXGLCubemap::getEnumForFaceNumber(face), mip, 0, 0, face, gGLDst->getHandle(), GL_TEXTURE_2D, mip, 0, 0, 0, mipSize, mipSize, mip);
-         glTexSubImage2D(gGLDst->getBinding(), mip, 0, 0, mipSize, mipSize, GFXGLTextureFormat[format], GFXGLTextureType[format], pixelData);
-      }
-      glBindTexture(gGLDst->getBinding(), 0);
+         U8* pixelData = pGLSrc->getTextureData(face, mip);
+
+         glBindTexture(gGLDst->getBinding(), gGLDst->getHandle());
+         if (isCompressed)
+         {
+            const U32 mipDataSize = getCompressedSurfaceSize(format, pGLSrc->getSize(), pGLSrc->getSize(), 0);
 
-      delete[] pixelData;
+            glCompressedTexSubImage2D(gGLDst->getBinding(), mip, 0, 0, mipSize, mipSize, GFXGLTextureFormat[format], mipDataSize, pixelData);
+         }
+         else
+         {
+            glTexSubImage2D(gGLDst->getBinding(), mip, 0, 0, mipSize, mipSize, GFXGLTextureFormat[format], GFXGLTextureType[format], pixelData);
+         }
+         glBindTexture(gGLDst->getBinding(), 0);
+
+         delete[] pixelData;
+      }
    }
 }
 

Engine/source/gfx/gl/gfxGLTextureObject.cpp

@@ -177,7 +177,6 @@ bool GFXGLTextureObject::copyToBmp(GBitmap * bmp)
    
 
    U32 mipLevels = getMipLevels();
-   if (mipLevels < 1) mipLevels = 1;//ensure we loop at least the once
    for (U32 mip = 0; mip < mipLevels; mip++)
    {
       U32 srcPixelCount = bmp->getSurfaceSize(mip)/ srcBytesPerPixel;
@@ -207,6 +206,7 @@ bool GFXGLTextureObject::copyToBmp(GBitmap * bmp)
          }
       }
    }
+   glBindTexture(mBinding, NULL);
    PROFILE_END();
 
    return true;