Creating functions for uploading a mipmapped texture.

src/gpu/SkGr.cpp

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkGr.h"
 
 #include "GrCaps.h"
 #include "GrDrawContext.h"
 #include "GrXferProcessor.h"
 #include "GrYUVProvider.h"
 
 #include "SkColorFilter.h"
 #include "SkConfig8888.h"
 #include "SkCanvas.h"
 #include "SkData.h"
 #include "SkErrorInternals.h"
 #include "SkGrPixelRef.h"
 #include "SkMessageBus.h"
+#include "SkMipMap.h"
 #include "SkPixelRef.h"
 #include "SkResourceCache.h"
 #include "SkTextureCompressor.h"
 #include "SkYUVPlanesCache.h"
 #include "effects/GrBicubicEffect.h"
 #include "effects/GrDitherEffect.h"
 #include "effects/GrPorterDuffXferProcessor.h"
 #include "effects/GrYUVtoRGBEffect.h"
 
 #ifndef SK_IGNORE_ETC1_SUPPORT
@@ skipping 597 matching lines @@
     const GrTextureParams::FilterMode filters[] = {
         GrTextureParams::kNone_FilterMode,      // kUntiled_SkImageUsageType
         GrTextureParams::kNone_FilterMode,      // kTiled_Unfiltered_SkImageUsageType
         GrTextureParams::kBilerp_FilterMode,    // kTiled_Filtered_SkImageUsageType
     };
 
     GrTextureParams params(tiles[usage], filters[usage]);
     return GrRefCachedBitmapTexture(ctx, bitmap, &params);
 }
 
+GrTexture* GrMipMapTexture(GrContext* ctx,
+                           const SkBitmap& bitmap,
+                           SkDiscardableFactoryProc fact) {
+    // If the SkBitmap is already backed by a texture, we do not want to read the contents back
+    // to the cpu and generate the mipmap only to send it back to the GPU.
+    SkASSERT(!bitmap.getTexture());
+
+    GrSurfaceDesc desc;
+    generate_bitmap_texture_desc(bitmap, &desc);
+
+    auto mipmap = SkMipMap::Build(bitmap, fact);
+    if (mipmap == NULL) {
+        // could not create the mipmap
+        return NULL;
+    } else {
+        auto mipLevelCount = mipmap->getLevelsCount();
+        desc.fIsMipMapped = mipLevelCount > 1;
+        SkTArray<SkMipMapLevel> texels(mipLevelCount);
+        for (int i = 0; i < mipLevelCount; i++) {
+            SkMipMap::Level level;
+            mipmap->getLevel(i, &level);
+
+            SkMipMapLevel currentMipLevel(level.fPixels, level.fRowBytes);
+
+            texels.push_back(currentMipLevel);
+        }
+        return ctx->textureProvider()->createTexture(desc, true, texels);
+        // TODO: BitmapInvalidator support
+    }
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 // alphatype is ignore for now, but if GrPixelConfig is expanded to encompass
 // alpha info, that will be considered.
 GrPixelConfig SkImageInfo2GrPixelConfig(SkColorType ct, SkAlphaType, SkColorProfileType pt) {
     switch (ct) {
         case kUnknown_SkColorType:
             return kUnknown_GrPixelConfig;
         case kAlpha_8_SkColorType:
             return kAlpha_8_GrPixelConfig;
@@ skipping 200 matching lines @@
             SkErrorInternals::SetError( kInvalidPaint_SkError,
                                         "Sorry, I don't understand the filtering "
                                         "mode you asked for.  Falling back to "
                                         "MIPMaps.");
             textureFilterMode = GrTextureParams::kMipMap_FilterMode;
             break;
 
     }
     return textureFilterMode;
 }