Texture compression unit tests along with a couple of bug fixes

tests/TextureCompressionTest.cpp

Index: tests/TextureCompressionTest.cpp
diff --git a/tests/TextureCompressionTest.cpp b/tests/TextureCompressionTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..d0671408e9ff70eae24b0a16e2318f88315ce757
--- /dev/null
+++ b/tests/TextureCompressionTest.cpp
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkBitmap.h"
+#include "SkData.h"
+#include "SkEndian.h"
+#include "SkImageInfo.h"
+#include "SkTextureCompressor.h"
+#include "Test.h"
+
+static const int kLATCBlockDimension = 4;
+static const int kLATCEncodedBlockSize = 8;
+
+/**
+ * Make sure that we properly fail when we don't have multiple of four image dimensions.
+ */
+DEF_TEST(CompressLATCFailure, reporter) {
+    SkBitmap bitmap;

[robertphillips, 2014/06/11 18:16:35]

kWidth & kHeight ?

[krajcevski, 2014/06/11 18:51:10]

Done.

+    static const int width = 63;
+    static const int height = 63;

[robertphillips, 2014/06/11 18:16:35]

MakeA8? kOpaque ??

[krajcevski, 2014/06/11 18:51:10]

Done.

+    SkImageInfo info = SkImageInfo::Make(width, height,
+                                         kAlpha_8_SkColorType,
+                                         kOpaque_SkAlphaType);
+    REPORTER_ASSERT(reporter, width % kLATCBlockDimension != 0);
+    REPORTER_ASSERT(reporter, height % kLATCBlockDimension != 0);
+

[robertphillips, 2014/06/11 18:16:36]

Make the next two lines one line ?

[krajcevski, 2014/06/11 18:51:10]

Done.

+    bool setInfoSuccess = false;
+    setInfoSuccess = bitmap.setInfo(info);
+    REPORTER_ASSERT(reporter, setInfoSuccess);
+

[robertphillips, 2014/06/11 18:16:35]

1 line?

[krajcevski, 2014/06/11 18:51:10]

Done.

+    bool allocPixelsSuccess = false;
+    allocPixelsSuccess = bitmap.allocPixels(info);
+    REPORTER_ASSERT(reporter, allocPixelsSuccess);
+    bitmap.unlockPixels();
+
+    const SkTextureCompressor::Format kLATCFormat = SkTextureCompressor::kLATC_Format;

[robertphillips, 2014/06/11 18:16:35]

What makes this bitmap white?

[krajcevski, 2014/06/11 18:51:10]

Artifact of copypasta. Fixed.

+    SkAutoDataUnref whiteLATC(SkTextureCompressor::CompressBitmapToFormat(bitmap, kLATCFormat));
+    REPORTER_ASSERT(reporter, NULL == whiteLATC);
+}
+
+/**
+ * Make sure that if we pass in a solid color bitmap that we get the appropriate results
+ */
+DEF_TEST(CompressLATC, reporter) {
+    SkBitmap bitmap;

[robertphillips, 2014/06/11 18:16:35]

kWidth, kHeight?

[krajcevski, 2014/06/11 18:51:11]

Done.

+    static const int width = 8;
+    static const int height = 8;

[robertphillips, 2014/06/11 18:16:35]

Same as above ?

[krajcevski, 2014/06/11 18:51:11]

Done.

+    SkImageInfo info = SkImageInfo::Make(width, height,
+                                         kAlpha_8_SkColorType,
+                                         kOpaque_SkAlphaType);
+

[robertphillips, 2014/06/11 18:16:36]

1 line ?

[krajcevski, 2014/06/11 18:51:11]

Done.

+    bool setInfoSuccess = false;
+    setInfoSuccess = bitmap.setInfo(info);
+    REPORTER_ASSERT(reporter, setInfoSuccess);
+

[robertphillips, 2014/06/11 18:16:36]

1 line ?

[krajcevski, 2014/06/11 18:51:10]

Done.

+    bool allocPixelsSuccess = false;
+    allocPixelsSuccess = bitmap.allocPixels(info);
+    REPORTER_ASSERT(reporter, allocPixelsSuccess);
+

[robertphillips, 2014/06/11 18:16:35]

I would just ditch this test here and check it every time you grab the pixels in
the loop.

[krajcevski, 2014/06/11 18:51:10]

Done.

+    uint8_t* pixels = reinterpret_cast<uint8_t*>(bitmap.getPixels());
+    bitmap.unlockPixels();
+    REPORTER_ASSERT(reporter, NULL != pixels);
+
+    REPORTER_ASSERT(reporter, width % kLATCBlockDimension == 0);
+    REPORTER_ASSERT(reporter, height % kLATCBlockDimension == 0);
+    int numBlocks = (width / kLATCBlockDimension) * (height / kLATCBlockDimension);
+
+    for (int lum = 0; lum < 256; ++lum) {

[robertphillips, 2014/06/11 18:16:36]

regrab the pixels in here ?

[krajcevski, 2014/06/11 18:51:11]

Done.

+        bitmap.lockPixels();
+        for (int i = 0; i < width*height; ++i) {
+            pixels[i] = lum;
+        }
+        bitmap.unlockPixels();
+
+        const SkTextureCompressor::Format kLATCFormat = SkTextureCompressor::kLATC_Format;
+        SkAutoDataUnref latcData(
+            SkTextureCompressor::CompressBitmapToFormat(bitmap, kLATCFormat));
+        REPORTER_ASSERT(reporter, NULL != latcData);
+

[robertphillips, 2014/06/11 18:16:36]

Move kSizeToBe out of the loop?

[krajcevski, 2014/06/11 18:51:11]

Done.

+        const size_t kSizeToBe = static_cast<size_t>(kLATCEncodedBlockSize * numBlocks);
+        REPORTER_ASSERT(reporter, kSizeToBe == latcData->size());
+
+        // Make sure that it all matches a given block encoding.

[robertphillips, 2014/06/11 18:16:35]

Rename 'encoding' 'encodedConstColorBlock' - or something?
Add a comment about why this is the encoding for a constant color block?

[krajcevski, 2014/06/11 18:51:10]

Done.

+        const uint64_t encoding = SkEndian_SwapLE64(lum | (lum << 8));
+        const uint64_t* blockPtr = reinterpret_cast<const uint64_t*>(latcData->data());

[robertphillips, 2014/06/11 18:16:36]

++i ?

[krajcevski, 2014/06/11 18:51:11]

Done.

+        for (int i = 0; i < numBlocks; i++) {
+            REPORTER_ASSERT(reporter, blockPtr[i] == encoding);
+        }
+    }
+}