We were numerically overflowing our 16bit coordinates that we communicate
between these two procs. The fixes was in two parts:
1. Just don't draw bitmaps larger than 64K-1 in width or height, since we
can't represent those coordinates in our transport format (yet).
2. Perform an unsigned shift during the calculation, so we don't get
sign-extension bleed when packing the two values (X,Y) into our 32bit
slot.
Review URL: https://codereview.appspot.com/6173046
git-svn-id: http://skia.googlecode.com/svn/trunk@3836 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/DrawBitmapRectTest.cpp b/tests/DrawBitmapRectTest.cpp
index e5b4463..ec6fa12 100644
--- a/tests/DrawBitmapRectTest.cpp
+++ b/tests/DrawBitmapRectTest.cpp
@@ -8,6 +8,101 @@
#include "Test.h"
#include "SkBitmap.h"
#include "SkCanvas.h"
+#include "SkShader.h"
+
+static void assert_ifDrawnTo(skiatest::Reporter* reporter,
+ const SkBitmap& bm, bool shouldBeDrawn) {
+ for (int y = 0; y < bm.height(); ++y) {
+ for (int x = 0; x < bm.width(); ++x) {
+ if (shouldBeDrawn) {
+ if (0 == *bm.getAddr32(x, y)) {
+ REPORTER_ASSERT(reporter, false);
+ return;
+ }
+ } else {
+ // should not be drawn
+ if (*bm.getAddr32(x, y)) {
+ REPORTER_ASSERT(reporter, false);
+ return;
+ }
+ }
+ }
+ }
+}
+
+static void test_wacky_bitmapshader(skiatest::Reporter* reporter,
+ int width, int height, bool shouldBeDrawn) {
+ SkBitmap dev;
+ dev.setConfig(SkBitmap::kARGB_8888_Config, 0x56F, 0x4f6);
+ dev.allocPixels();
+ dev.eraseColor(0); // necessary, so we know if we draw to it
+
+ SkMatrix matrix;
+
+ SkCanvas c(dev);
+ matrix.setAll(-119.34097, -43.436558, 93489.945,
+ 43.436558, -119.34097, 123.98426,
+ 0, 0, 1);
+ c.concat(matrix);
+
+ SkBitmap bm;
+ bm.setConfig(SkBitmap::kARGB_8888_Config, width, height);
+ bm.allocPixels();
+ bm.eraseColor(SK_ColorRED);
+
+ SkShader* s = SkShader::CreateBitmapShader(bm, SkShader::kRepeat_TileMode,
+ SkShader::kRepeat_TileMode);
+ matrix.setAll(0.0078740157, 0, 249,
+ 0, 0.0078740157, 239,
+ 0, 0, 1);
+ s->setLocalMatrix(matrix);
+
+ SkPaint paint;
+ paint.setShader(s)->unref();
+
+ SkRect r = SkRect::MakeXYWH(681, 239, 695, 253);
+ c.drawRect(r, paint);
+
+ assert_ifDrawnTo(reporter, dev, shouldBeDrawn);
+}
+
+/*
+ * Original bug was asserting that the matrix-proc had generated a (Y) value
+ * that was out of range. This led (in the release build) to the sampler-proc
+ * reading memory out-of-bounds of the original bitmap.
+ *
+ * We were numerically overflowing our 16bit coordinates that we communicate
+ * between these two procs. The fixes was in two parts:
+ *
+ * 1. Just don't draw bitmaps larger than 64K-1 in width or height, since we
+ * can't represent those coordinates in our transport format (yet).
+ * 2. Perform an unsigned shift during the calculation, so we don't get
+ * sign-extension bleed when packing the two values (X,Y) into our 32bit
+ * slot.
+ *
+ * This tests exercises the original setup, plus 3 more to ensure that we can,
+ * in fact, handle bitmaps at 64K-1 (assuming we don't exceed the total
+ * memory allocation limit).
+ */
+static void test_giantrepeat_crbug118018(skiatest::Reporter* reporter) {
+ static const struct {
+ int fWidth;
+ int fHeight;
+ bool fExpectedToDraw;
+ } gTests[] = {
+ { 0x1b294, 0x7f, false }, // crbug 118018 (width exceeds 64K)
+ { 0xFFFF, 0x7f, true }, // should draw, test max width
+ { 0x7f, 0xFFFF, true }, // should draw, test max height
+ { 0xFFFF, 0xFFFF, false }, // allocation fails (too much RAM)
+ };
+
+ for (size_t i = 0; i < SK_ARRAY_COUNT(gTests); ++i) {
+ test_wacky_bitmapshader(reporter,
+ gTests[i].fWidth, gTests[i].fHeight,
+ gTests[i].fExpectedToDraw);
+ }
+}
+///////////////////////////////////////////////////////////////////////////////
static void test_nan_antihair(skiatest::Reporter* reporter) {
SkBitmap bm;
@@ -72,6 +167,7 @@
REPORTER_ASSERT(reporter, check_for_all_zeros(dst));
test_nan_antihair(reporter);
+ test_giantrepeat_crbug118018(reporter);
}
#include "TestClassDef.h"