Make astc works on ios platform.

cocos/renderer/CCTexture2D.cpp

@@ -281,8 +281,8 @@ bool Texture2D::updateWithImage(Image* image, backend::PixelFormat format, int i
     case PixelFormat::ASTC4:
     case PixelFormat::ASTC8:
         renderFormat = imagePixelFormat;
-    default:
         break;
+    default:;
     }
     //override renderFormat, since some render format is not supported by metal
     switch (renderFormat)
@@ -326,14 +326,16 @@ bool Texture2D::updateWithImage(Image* image, backend::PixelFormat format, int i
     }
     else if (image->isCompressed())
     {   
+#ifndef CC_USE_METAL
         switch (imagePixelFormat) {
+        case PixelFormat::ETC:
         case PixelFormat::ASTC4:
         case PixelFormat::ASTC8:
-        case PixelFormat::ETC:
             renderFormat = imagePixelFormat;
+            break;
         default:;
         }
-
+#endif
         if (renderFormat != image->getPixelFormat())
         {
             CCLOG("cocos2d: WARNING: This image is compressed and we can't convert it for now");

cocos/renderer/backend/metal/TextureMTL.mm

@@ -140,6 +140,30 @@ namespace
         return bytesPerRow;
     }
     
+    std::size_t getBytesPerRowASTC(MTLPixelFormat pixleFormat, std::size_t width)
+    {
+        std::size_t bytesPerRow = 0;
+#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)
+        uint32_t bytesPerBlock = 0;
+        switch (pixleFormat) {
+            case MTLPixelFormatASTC_4x4_sRGB:
+            case MTLPixelFormatASTC_4x4_LDR:
+            case MTLPixelFormatASTC_4x4_HDR:
+                bytesPerBlock = 4;
+                break;
+            case MTLPixelFormatASTC_8x8_sRGB:
+            case MTLPixelFormatASTC_8x8_LDR:
+            case MTLPixelFormatASTC_8x8_HDR:
+                bytesPerBlock = 8;
+                break;
+            default:
+                CCASSERT(false, "Not supported ASTC format!");
+        }
+        bytesPerRow = width * bytesPerBlock;
+#endif
+        return bytesPerRow;
+    }
+    
     std::size_t getBytesPerRowS3TC(MTLPixelFormat pixleFormat, std::size_t width)
     {
         std::size_t bytesPerRow = 0;
@@ -176,6 +200,10 @@ namespace
         {
             bytesPerRow = getBytesPerRowETC(pixelFormat, width);
         }
+        else if (textureFormat == PixelFormat::ASTC4 || textureFormat == PixelFormat::ASTC8)
+        {
+            bytesPerRow = getBytesPerRowASTC(pixelFormat, width);
+        }
         else if(textureFormat >= PixelFormat::S3TC_DXT1 &&
                 textureFormat <= PixelFormat::S3TC_DXT5)
         {

cocos/renderer/backend/metal/Utils.mm

@@ -123,6 +123,10 @@ MTLPixelFormat Utils::toMTLPixelFormat(PixelFormat textureFormat)
             return MTLPixelFormatPVRTC_RGB_2BPP;
         case PixelFormat::ETC:
             return MTLPixelFormatETC2_RGB8;
+        case PixelFormat::ASTC4:
+            return MTLPixelFormatASTC_4x4_LDR;
+        case PixelFormat::ASTC8:
+            return MTLPixelFormatASTC_8x8_LDR;
 #else
         case PixelFormat::S3TC_DXT1:
             return MTLPixelFormatBC1_RGBA;