add fFx1 field, returning where to start the iterator for fCount1 range
add unittest
git-svn-id: http://skia.googlecode.com/svn/trunk@1145 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/core/SkClampRange.h b/include/core/SkClampRange.h
index b80c78b..999faa0 100644
--- a/include/core/SkClampRange.h
+++ b/include/core/SkClampRange.h
@@ -31,11 +31,12 @@
int fCount0; // count for fV0
int fCount1; // count for interpolating (fV0...fV1)
int fCount2; // count for fV1
+ SkFixed fFx1; // initial fx value for the fCount1 range.
+ // only valid if fCount1 > 0
int fV0, fV1;
+ bool fOverflowed; // true if we had to clamp due to numerical overflow
void init(SkFixed fx, SkFixed dx, int count, int v0, int v1);
-
- static void UnitTest();
};
#endif
diff --git a/src/core/SkClampRange.cpp b/src/core/SkClampRange.cpp
index 222b8a4..be41067 100644
--- a/src/core/SkClampRange.cpp
+++ b/src/core/SkClampRange.cpp
@@ -42,12 +42,24 @@
fV0 = v0;
fV1 = v1;
+ // check for over/underflow
+ {
+ int64_t eex = (int64_t)fx + count * (int64_t)dx;
+ if (eex > SK_FixedMax) {
+
+ } else if (eex < -SK_FixedMax) {
+ }
+ }
+
+ // remember our original fx
+ const SkFixed fx0 = fx;
// start with ex equal to the last computed value
SkFixed ex = fx + (count - 1) * dx;
if ((unsigned)(fx | ex) <= 0xFFFF) {
fCount0 = fCount2 = 0;
fCount1 = count;
+ fFx1 = fx;
return;
}
if (fx <= 0 && ex <= 0) {
@@ -96,83 +108,11 @@
if (doSwap) {
SkTSwap(fCount0, fCount2);
SkTSwap(fV0, fV1);
+ dx = -dx;
+ }
+
+ if (fCount1 > 0) {
+ fFx1 = fx0 + fCount0 * dx;
}
}
-////////////////////////////
-#include "SkRandom.h"
-
-#ifdef SK_DEBUG
-static bool in_range(int x, int target, int slop) {
- SkASSERT(slop >= 0);
- return SkAbs32(x - target) <= slop;
-}
-
-static int classify_value(SkFixed fx, int v0, int v1) {
- if (fx <= 0) {
- return v0;
- }
- if (fx >= 0xFFFF) {
- return v1;
- }
- SkASSERT(!"bad fx");
- return 0;
-}
-
-#define V0 -42
-#define V1 1024
-
-static void slow_check(const SkClampRange& range,
- SkFixed fx, SkFixed dx, int count) {
- SkASSERT(range.fCount0 + range.fCount1 + range.fCount2 == count);
-
- int i;
- for (i = 0; i < range.fCount0; i++) {
- int v = classify_value(fx, V0, V1);
- SkASSERT(v == range.fV0);
- fx += dx;
- }
- for (i = 0; i < range.fCount1; i++) {
- SkASSERT(fx >= 0 && fx <= 0xFFFF);
- fx += dx;
- }
- for (i = 0; i < range.fCount2; i++) {
- int v = classify_value(fx, V0, V1);
- SkASSERT(v == range.fV1);
- fx += dx;
- }
-}
-
-static void test_range(SkFixed fx, SkFixed dx, int count) {
- SkClampRange range;
- range.init(fx, dx, count, V0, V1);
- slow_check(range, fx, dx, count);
-}
-
-#define ff(x) SkIntToFixed(x)
-
-void SkClampRange::UnitTest() {
- test_range(0, 0, 20);
- test_range(0xFFFF, 0, 20);
- test_range(-ff(2), 0, 20);
- test_range( ff(2), 0, 20);
-
- test_range(-10, 1, 20);
- test_range(10, -1, 20);
- test_range(-10, 3, 20);
- test_range(10, -3, 20);
-
- SkRandom rand;
-
- for (int i = 0; i < 1000000; i++) {
- SkFixed fx = rand.nextS() >> 1;
- SkFixed sx = rand.nextS() >> 1;
- int count = rand.nextU() % 1000 + 1;
- SkFixed dx = (sx - fx) / count;
- test_range(fx, dx, count);
- }
-}
-#else
-void SkClampRange::UnitTest() {}
-#endif
-
diff --git a/tests/ClampRangeTest.cpp b/tests/ClampRangeTest.cpp
new file mode 100644
index 0000000..b3d1e78
--- /dev/null
+++ b/tests/ClampRangeTest.cpp
@@ -0,0 +1,86 @@
+#include "Test.h"
+#include "SkClampRange.h"
+#include "SkRandom.h"
+
+static skiatest::Reporter* gReporter;
+
+static int classify_value(SkFixed fx, int v0, int v1) {
+ if (fx <= 0) {
+ return v0;
+ }
+ if (fx >= 0xFFFF) {
+ return v1;
+ }
+ REPORTER_ASSERT(gReporter, false);
+ return 0;
+}
+
+#define V0 -42
+#define V1 1024
+
+static void slow_check(const SkClampRange& range,
+ SkFixed fx, SkFixed dx, int count) {
+ SkASSERT(range.fCount0 + range.fCount1 + range.fCount2 == count);
+
+ int i;
+ for (i = 0; i < range.fCount0; i++) {
+ int v = classify_value(fx, V0, V1);
+ REPORTER_ASSERT(gReporter, v == range.fV0);
+ fx += dx;
+ }
+ REPORTER_ASSERT(gReporter, range.fCount1 == 0 || fx == range.fFx1);
+ for (i = 0; i < range.fCount1; i++) {
+ REPORTER_ASSERT(gReporter, fx >= 0 && fx <= 0xFFFF);
+ fx += dx;
+ }
+ for (i = 0; i < range.fCount2; i++) {
+ int v = classify_value(fx, V0, V1);
+ REPORTER_ASSERT(gReporter, v == range.fV1);
+ fx += dx;
+ }
+}
+
+static void test_range(SkFixed fx, SkFixed dx, int count) {
+ SkClampRange range;
+ range.init(fx, dx, count, V0, V1);
+ slow_check(range, fx, dx, count);
+}
+
+#define ff(x) SkIntToFixed(x)
+
+static void TestClampRange(skiatest::Reporter* reporter) {
+ gReporter = reporter;
+
+ test_range(0, 0, 20);
+ test_range(0xFFFF, 0, 20);
+ test_range(-ff(2), 0, 20);
+ test_range( ff(2), 0, 20);
+
+ test_range(-10, 1, 20);
+ test_range(10, -1, 20);
+ test_range(-10, 3, 20);
+ test_range(10, -3, 20);
+
+ SkRandom rand;
+
+ // test non-overflow cases
+ for (int i = 0; i < 1000000; i++) {
+ SkFixed fx = rand.nextS() >> 1;
+ SkFixed sx = rand.nextS() >> 1;
+ int count = rand.nextU() % 1000 + 1;
+ SkFixed dx = (sx - fx) / count;
+ test_range(fx, dx, count);
+ }
+
+ // test overflow cases
+ for (int i = 0; i < 0*1000000; i++) {
+ SkFixed fx = rand.nextS();
+ SkFixed sx = rand.nextS();
+ int count = rand.nextU() % 1000 + 1;
+ SkFixed dx = (sx - fx) / count;
+ test_range(fx, dx, count);
+ }
+}
+
+#include "TestClassDef.h"
+DEFINE_TESTCLASS("ClampRange", ClampRangeClass, TestClampRange)
diff --git a/tests/tests_files.mk b/tests/tests_files.mk
index 526a219..f78481a 100644
--- a/tests/tests_files.mk
+++ b/tests/tests_files.mk
@@ -2,6 +2,7 @@
BitmapCopyTest.cpp \
BitmapGetColorTest.cpp \
BlitRowTest.cpp \
+ ClampRangeTest.cpp \
ClipCubicTest.cpp \
ClipStackTest.cpp \
ClipperTest.cpp \