test scalePixels and unpremul

Bug: skia:5733
Change-Id: I6c661408198f6a536e1e55ba01d976948446b8eb
Reviewed-on: https://skia-review.googlesource.com/70280
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/gm/image.cpp b/gm/image.cpp
index 6bf9f01154..576d7e8f98 100644
--- a/gm/image.cpp
+++ b/gm/image.cpp
@@ -381,3 +381,39 @@ DEF_SIMPLE_GM(new_texture_image, canvas, 280, 60) {
         canvas->translate(kSize + kPad, 0);
     }
 }
+
+static void draw_pixmap(SkCanvas* canvas, const SkPixmap& pm, SkScalar x, SkScalar y) {
+    canvas->drawImage(SkImage::MakeRasterCopy(pm), x, y, nullptr);
+}
+
+static void slam_ff(const SkPixmap& pm) {
+    for (int y = 0; y < pm.height(); ++y) {
+        for (int x = 0; x < pm.width(); ++x) {
+            *pm.writable_addr32(x, y) = *pm.addr32(x, y) | SkPackARGB32(0xFF, 0, 0, 0);
+        }
+    }
+}
+
+DEF_SIMPLE_GM(scalepixels_unpremul, canvas, 1080, 280) {
+    SkImageInfo info = SkImageInfo::MakeN32(16, 16, kUnpremul_SkAlphaType);
+    SkAutoPixmapStorage pm;
+    pm.alloc(info);
+    for (int y = 0; y < 16; ++y) {
+        for (int x = 0; x < 16; ++x) {
+            *pm.writable_addr32(x, y) = SkPackARGB32NoCheck(0, (y << 4) | y, (x << 4) | x, 0xFF);
+        }
+    }
+    SkAutoPixmapStorage pm2;
+    pm2.alloc(SkImageInfo::MakeN32(256, 256, kUnpremul_SkAlphaType));
+
+    const SkFilterQuality qualities[] = {
+        kNone_SkFilterQuality, kLow_SkFilterQuality, kMedium_SkFilterQuality, kHigh_SkFilterQuality
+    };
+
+    for (auto fq : qualities) {
+        pm.scalePixels(pm2, fq);
+        slam_ff(pm2);
+        draw_pixmap(canvas, pm2, 10, 10);
+        canvas->translate(pm2.width() + 10.0f, 0);
+    }
+}