Allow index sources to be unpremul.

src/images/SkScaledBitmapSampler.cpp

 /*
  * Copyright 2007 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkScaledBitmapSampler.h"
 #include "SkBitmap.h"
@@ skipping 378 matching lines @@
         if (c != 0) {
             dst[x] = c;
         }
         src += deltaSrc;
     }
     return cc != A32_MASK_IN_PLACE;
 }
 
 static SkScaledBitmapSampler::RowProc
 get_index_to_8888_proc(const SkScaledBitmapSampler::Options& opts) {
-    if (!opts.fPremultiplyAlpha) {
-        // Unpremultiplied is not supported for an index source.
-        return NULL;
-    }
+    // The caller is expected to have created the source colortable
+    // properly with respect to opts.fPremultiplyAlpha, so premul makes
+    // no difference here.
     // Dither makes no difference
     if (opts.fSkipZeros) {
         return Sample_Index_D8888_SkipZ;
     }
     return Sample_Index_D8888;
 }
 
 static bool Sample_Index_D565(void* SK_RESTRICT dstRow,
                                const uint8_t* SK_RESTRICT src,
                        int width, int deltaSrc, int, const SkPMColor ctable[]) {
@@ skipping 383 matching lines @@
     Sample_Gray_DA8,    Sample_Gray_DA8,        NULL,                       NULL,                       // to A8
     NULL,               NULL,                   NULL,                       NULL,                       // to Index8
     Sample_Gray_D565,   Sample_Gray_D565_D,     Sample_Gray_D565,           Sample_Gray_D565_D,         // to 565
     Sample_Gray_D4444,  Sample_Gray_D4444_D,    Sample_Gray_D4444,          Sample_Gray_D4444_D,        // to 4444
     Sample_Gray_D8888,  Sample_Gray_D8888,      Sample_Gray_D8888,          Sample_Gray_D8888,          // to 8888
     // Index
     NULL,               NULL,                   NULL,                       NULL,                       // to A8
     Sample_Index_DI,    Sample_Index_DI,        NULL,                       NULL,                       // to Index8
     Sample_Index_D565,  Sample_Index_D565_D,    Sample_Index_D565,          Sample_Index_D565_D,        // to 565
     Sample_Index_D4444, Sample_Index_D4444_D,   NULL,                       NULL,                       // to 4444
-    Sample_Index_D8888, Sample_Index_D8888,     NULL,                       NULL,                       // to 8888
+    Sample_Index_D8888, Sample_Index_D8888,     Sample_Index_D8888,         Sample_Index_D8888,         // to 8888
     // RGB
     NULL,               NULL,                   NULL,                       NULL,                       // to A8
     NULL,               NULL,                   NULL,                       NULL,                       // to Index8
     Sample_RGBx_D565,   Sample_RGBx_D565_D,     Sample_RGBx_D565,           Sample_RGBx_D565_D,         // to 565
     Sample_RGBx_D4444,  Sample_RGBx_D4444_D,    Sample_RGBx_D4444,          Sample_RGBx_D4444_D,        // to 4444
     Sample_RGBx_D8888,  Sample_RGBx_D8888,      Sample_RGBx_D8888,          Sample_RGBx_D8888,          // to 8888
     // RGBx is the same as RGB
     NULL,               NULL,                   NULL,                       NULL,                       // to A8
     NULL,               NULL,                   NULL,                       NULL,                       // to Index8
     Sample_RGBx_D565,   Sample_RGBx_D565_D,     Sample_RGBx_D565,           Sample_RGBx_D565_D,         // to 565
@@ skipping 50 matching lines @@
                     SkScaledBitmapSampler::RowProc actual = RowProcTester::getRowProc(sampler);
                     SkASSERT(expected == actual);
                     procCounter++;
                 }
             }
         }
     }
     SkASSERT(SK_ARRAY_COUNT(gTestProcs) == procCounter);
 }
 #endif // SK_DEBUG