[PDF] Add unpremultiply support and a GM (try5)
This is a resubmit of https://codereview.chromium.org/22831039 which was
reverted because it causes issues on Windows.
BUG=chromium:175548
R=edisonn@google.com
Review URL: https://codereview.chromium.org/37873003
git-svn-id: http://skia.googlecode.com/svn/trunk@11945 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/bitmappremul.cpp b/gm/bitmappremul.cpp
new file mode 100644
index 0000000..8b4c2d6
--- /dev/null
+++ b/gm/bitmappremul.cpp
@@ -0,0 +1,133 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "gm.h"
+#include "SkBitmap.h"
+#include "SkCanvas.h"
+#include "SkColorPriv.h"
+
+/**
+ * This GM checks that bitmap pixels are unpremultiplied before being exported
+ * to other formats. If unpremultiplication is implemented properly, this
+ * GM should come out completely white. If not, this GM looks like a row of two
+ * greyscale gradients above a row of grey lines.
+ * This tests both the ARGB4444 and ARGB8888 bitmap configurations.
+ */
+
+static const int SLIDE_SIZE = 256;
+static const int PIXEL_SIZE_8888 = SLIDE_SIZE / 256;
+static const int PIXEL_SIZE_4444 = SLIDE_SIZE / 16;
+
+static void init_bitmap(SkBitmap::Config config, SkBitmap* bitmap) {
+ bitmap->setConfig(config, SLIDE_SIZE, SLIDE_SIZE);
+ bitmap->allocPixels();
+ bitmap->eraseColor(SK_ColorWHITE);
+}
+
+static SkBitmap make_argb8888_gradient() {
+ SkBitmap bitmap;
+ init_bitmap(SkBitmap::kARGB_8888_Config, &bitmap);
+ uint8_t rowColor = 0;
+ for (int y = 0; y < SLIDE_SIZE; y++) {
+ uint32_t* dst = bitmap.getAddr32(0, y);
+ for (int x = 0; x < SLIDE_SIZE; x++) {
+ dst[x] = SkPackARGB32(rowColor, rowColor,
+ rowColor, rowColor);
+ }
+ if (y % PIXEL_SIZE_8888 == PIXEL_SIZE_8888 - 1) {
+ rowColor++;
+ }
+ }
+ return bitmap;
+}
+
+static SkBitmap make_argb4444_gradient() {
+ SkBitmap bitmap;
+ init_bitmap(SkBitmap::kARGB_4444_Config, &bitmap);
+ uint8_t rowColor = 0;
+ for (int y = 0; y < SLIDE_SIZE; y++) {
+ uint16_t* dst = bitmap.getAddr16(0, y);
+ for (int x = 0; x < SLIDE_SIZE; x++) {
+ dst[x] = SkPackARGB4444(rowColor, rowColor,
+ rowColor, rowColor);
+ }
+ if (y % PIXEL_SIZE_4444 == PIXEL_SIZE_4444 - 1) {
+ rowColor++;
+ }
+ }
+ return bitmap;
+}
+
+static SkBitmap make_argb8888_stripes() {
+ SkBitmap bitmap;
+ init_bitmap(SkBitmap::kARGB_8888_Config, &bitmap);
+ uint8_t rowColor = 0;
+ for (int y = 0; y < SLIDE_SIZE; y++) {
+ uint32_t* dst = bitmap.getAddr32(0, y);
+ for (int x = 0; x < SLIDE_SIZE; x++) {
+ dst[x] = SkPackARGB32(rowColor, rowColor,
+ rowColor, rowColor);
+ }
+ if (rowColor == 0) {
+ rowColor = 255;
+ } else {
+ rowColor = 0;
+ }
+ }
+ return bitmap;
+}
+
+static SkBitmap make_argb4444_stripes() {
+ SkBitmap bitmap;
+ init_bitmap(SkBitmap::kARGB_4444_Config, &bitmap);
+ uint8_t rowColor = 0;;
+ for (int y = 0; y < SLIDE_SIZE; y++) {
+ uint16_t* dst = bitmap.getAddr16(0, y);
+ for (int x = 0; x < SLIDE_SIZE; x++) {
+ dst[x] = SkPackARGB4444(rowColor, rowColor,
+ rowColor, rowColor);
+ }
+ if (rowColor == 0) {
+ rowColor = 15;
+ } else {
+ rowColor = 0;
+ }
+ }
+ return bitmap;
+}
+
+namespace skiagm {
+
+class BitmapPremulGM : public GM {
+public:
+ BitmapPremulGM() {
+ this->setBGColor(SK_ColorWHITE);
+ }
+
+protected:
+ SkString onShortName() SK_OVERRIDE {
+ return SkString("bitmap_premul");
+ }
+
+ virtual SkISize onISize() SK_OVERRIDE {
+ return SkISize::Make(SLIDE_SIZE * 2, SLIDE_SIZE * 2);
+ }
+
+ virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+ SkScalar slideSize = SkIntToScalar(SLIDE_SIZE);
+ canvas->drawBitmap(make_argb8888_gradient(), 0, 0);
+ canvas->drawBitmap(make_argb4444_gradient(), slideSize, 0);
+ canvas->drawBitmap(make_argb8888_stripes(), 0, slideSize);
+ canvas->drawBitmap(make_argb4444_stripes(), slideSize, slideSize);
+ }
+
+private:
+ typedef GM INHERITED;
+};
+
+DEF_GM( return new BitmapPremulGM; )
+}