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-rw-r--r--gn/core.gni2
-rw-r--r--src/core/SkAnalyticEdge.cpp37
-rw-r--r--src/core/SkFDot6.h37
-rw-r--r--src/core/SkFDot6Constants.h (renamed from src/core/SkAAAConstants.h)21
-rw-r--r--tests/MathTest.cpp34
5 files changed, 75 insertions, 56 deletions
diff --git a/gn/core.gni b/gn/core.gni
index d7f11569a8..fcc8de1f74 100644
--- a/gn/core.gni
+++ b/gn/core.gni
@@ -121,7 +121,7 @@ skia_core_sources = [
"$_src/core/SkEmptyShader.h",
"$_src/core/SkEndian.h",
"$_src/core/SkAnalyticEdge.cpp",
- "$_src/core/SkAAAConstants.h",
+ "$_src/core/SkFDot6Constants.h",
"$_src/core/SkEdge.cpp",
"$_src/core/SkEdge.h",
"$_src/core/SkFDot6.h",
diff --git a/src/core/SkAnalyticEdge.cpp b/src/core/SkAnalyticEdge.cpp
index 17e3793ec0..a9cbc50204 100644
--- a/src/core/SkAnalyticEdge.cpp
+++ b/src/core/SkAnalyticEdge.cpp
@@ -9,37 +9,6 @@
#include "SkAnalyticEdge.h"
#include "SkFDot6.h"
#include "SkMathPriv.h"
-#include "SkAAAConstants.h"
-
-class QuickFDot6Inverse {
-private:
- static constexpr const SkFDot6* table = gFDot6INVERSE + kInverseTableSize;
-public:
- inline static SkFixed Lookup(SkFDot6 x) {
- SkASSERT(SkAbs32(x) < kInverseTableSize);
- return table[x];
- }
-};
-
-static inline SkFixed quickSkFDot6Div(SkFDot6 a, SkFDot6 b) {
- // Max inverse of b is 2^6 which is 2^22 in SkFixed format.
- // Hence the safe value of abs(a) should be less than 2^9.
- if (SkAbs32(b) < kInverseTableSize && SkAbs32(a) < (1 << 9)) {
- SkASSERT((int64_t)a * QuickFDot6Inverse::Lookup(b) <= SK_MaxS32
- && (int64_t)a * QuickFDot6Inverse::Lookup(b) >= SK_MinS32);
- SkFixed ourAnswer = (a * QuickFDot6Inverse::Lookup(b)) >> 6;
- #ifdef SK_DEBUG
- SkFixed directAnswer = SkFDot6Div(a, b);
- SkASSERT(
- (directAnswer == 0 && ourAnswer == 0) ||
- SkFixedDiv(SkAbs32(directAnswer - ourAnswer), SkAbs32(directAnswer)) <= 1 << 10
- );
- #endif
- return ourAnswer;
- } else {
- return SkFDot6Div(a, b);
- }
-}
// This will become a bottleneck for small ovals rendering if we call SkFixedDiv twice here.
// Therefore, we'll let the outter function compute the slope once and send in the value.
@@ -74,7 +43,7 @@ bool SkAnalyticEdge::updateLine(SkFixed x0, SkFixed y0, SkFixed x1, SkFixed y1,
? SK_MaxS32
: absSlope < kInverseTableSize
? QuickFDot6Inverse::Lookup(absSlope)
- : SkAbs32(quickSkFDot6Div(dy, dx));
+ : SkAbs32(QuickSkFDot6Div(dy, dx));
return true;
}
@@ -136,7 +105,7 @@ bool SkAnalyticQuadraticEdge::updateQuadratic() {
{
newx = oldx + (dx >> shift);
newy = oldy + (dy >> shift);
- slope = dy >> 10 > 0 ? quickSkFDot6Div(dx >> 10, dy >> 10) : SK_MaxS32;
+ slope = dy >> 10 > 0 ? QuickSkFDot6Div(dx >> 10, dy >> 10) : SK_MaxS32;
if (SkAbs32(dy) >= SK_Fixed1 * 2) { // only snap when dy is large enough
newSnappedY = SkTMin<SkFixed>(fQEdge.fQLastY, SkFixedRoundToFixed(newy));
newSnappedX = newx + SkFixedMul(slope, newSnappedY - newy);
@@ -154,7 +123,7 @@ bool SkAnalyticQuadraticEdge::updateQuadratic() {
newSnappedY = newy;
newSnappedX = newx;
slope = (newSnappedY - fSnappedY) >> 10
- ? quickSkFDot6Div((newx - fSnappedX) >> 10, (newy - fSnappedY) >> 10)
+ ? QuickSkFDot6Div((newx - fSnappedX) >> 10, (newy - fSnappedY) >> 10)
: SK_MaxS32;
}
if (slope < SK_MaxS32) {
diff --git a/src/core/SkFDot6.h b/src/core/SkFDot6.h
index 726aa2e46d..b9a5c2a12d 100644
--- a/src/core/SkFDot6.h
+++ b/src/core/SkFDot6.h
@@ -75,4 +75,41 @@ inline SkFixed SkFDot6Div(SkFDot6 a, SkFDot6 b) {
}
}
+#include "SkFDot6Constants.h"
+
+class QuickFDot6Inverse {
+private:
+ static constexpr const SkFDot6* table = gFDot6INVERSE + kInverseTableSize;
+public:
+ inline static SkFixed Lookup(SkFDot6 x) {
+ SkASSERT(SkAbs32(x) < kInverseTableSize);
+ return table[x];
+ }
+};
+
+static inline SkFixed QuickSkFDot6Div(SkFDot6 a, SkFDot6 b) {
+ const int kMinBits = 3; // abs(b) should be at least (1 << kMinBits) for quick division
+ const int kMaxBits = 31; // Number of bits available in signed int
+ // Given abs(b) <= (1 << kMinBits), the inverse of abs(b) is at most 1 << (22 - kMinBits) in
+ // SkFixed format. Hence abs(a) should be less than kMaxAbsA
+ const int kMaxAbsA = 1 << (kMaxBits - (22 - kMinBits));
+ SkFDot6 abs_a = SkAbs32(a);
+ SkFDot6 abs_b = SkAbs32(b);
+ if (abs_b >= (1 << kMinBits) && abs_b < kInverseTableSize && abs_a < kMaxAbsA) {
+ SkASSERT((int64_t)a * QuickFDot6Inverse::Lookup(b) <= SK_MaxS32
+ && (int64_t)a * QuickFDot6Inverse::Lookup(b) >= SK_MinS32);
+ SkFixed ourAnswer = (a * QuickFDot6Inverse::Lookup(b)) >> 6;
+ #ifdef SK_DEBUG
+ SkFixed directAnswer = SkFDot6Div(a, b);
+ SkASSERT(
+ (directAnswer == 0 && ourAnswer == 0) ||
+ SkFixedDiv(SkAbs32(directAnswer - ourAnswer), SkAbs32(directAnswer)) <= 1 << 10
+ );
+ #endif
+ return ourAnswer;
+ } else {
+ return SkFDot6Div(a, b);
+ }
+}
+
#endif
diff --git a/src/core/SkAAAConstants.h b/src/core/SkFDot6Constants.h
index e008e4b647..945bee522d 100644
--- a/src/core/SkAAAConstants.h
+++ b/src/core/SkFDot6Constants.h
@@ -10,26 +10,6 @@
static const int kInverseTableSize = 1024; // SK_FDot6One * 16
-/*
-The following table is generated by:
-
-struct FDot6InverseTable {
- SkFixed storage[kInverseTableSize * 2];
- SkFixed* table = storage + kInverseTableSize;
-
- FDot6InverseTable() {
- SkDebugf("static const int gFDot6INVERSE[] = {");
- for (SkFDot6 i=-kInverseTableSize; i<kInverseTableSize; i++) {
- if (i != 0) {
- table[i] = SkFDot6Div(SK_FDot6One, i);
- }
- SkDebugf("%d, ", table[i]);
- }
- SkDebugf("}\n");
- }
-};
-*/
-
static constexpr const SkFDot6 gFDot6INVERSE[kInverseTableSize * 2] = {
-4096, -4100, -4104, -4108, -4112, -4116, -4120, -4124, -4128, -4132, -4136,
-4140, -4144, -4148, -4152, -4156, -4161, -4165, -4169, -4173, -4177, -4181,
@@ -216,5 +196,4 @@ static constexpr const SkFDot6 gFDot6INVERSE[kInverseTableSize * 2] = {
4124, 4120, 4116, 4112, 4108, 4104, 4100
};
-
#endif
diff --git a/tests/MathTest.cpp b/tests/MathTest.cpp
index 35b4136b44..0bd3cf5da5 100644
--- a/tests/MathTest.cpp
+++ b/tests/MathTest.cpp
@@ -9,6 +9,7 @@
#include "SkColorPriv.h"
#include "SkEndian.h"
+#include "SkFDot6.h"
#include "SkFixed.h"
#include "SkFloatBits.h"
#include "SkFloatingPoint.h"
@@ -36,6 +37,38 @@ static void test_clz(skiatest::Reporter* reporter) {
}
}
+static void test_quick_div(skiatest::Reporter* reporter) {
+ /*
+ The inverse table is generated by turning on SkDebugf in the following test code
+ */
+ SkFixed storage[kInverseTableSize * 2];
+ SkFixed* table = storage + kInverseTableSize;
+
+ // SkDebugf("static const int gFDot6INVERSE[] = {");
+ for (SkFDot6 i=-kInverseTableSize; i<kInverseTableSize; i++) {
+ if (i != 0) {
+ table[i] = SkFDot6Div(SK_FDot6One, i);
+ REPORTER_ASSERT(reporter, table[i] == gFDot6INVERSE[i + kInverseTableSize]);
+ }
+ // SkDebugf("%d, ", table[i]);
+ }
+ // SkDebugf("}\n");
+
+
+ for (SkFDot6 a = -1024; a <= 1024; a++) {
+ for (SkFDot6 b = -1024; b <= 1024; b++) {
+ if (b != 0) {
+ SkFixed ourAnswer = QuickSkFDot6Div(a, b);
+ SkFixed directAnswer = SkFDot6Div(a, b);
+ REPORTER_ASSERT(reporter,
+ (directAnswer == 0 && ourAnswer == 0) ||
+ SkFixedDiv(SkAbs32(directAnswer - ourAnswer), SkAbs32(directAnswer)) <= 1 << 10
+ );
+ }
+ }
+ }
+}
+
///////////////////////////////////////////////////////////////////////////////
static float sk_fsel(float pred, float result_ge, float result_lt) {
@@ -576,6 +609,7 @@ DEF_TEST(Math, reporter) {
test_muldivround(reporter);
test_clz(reporter);
+ test_quick_div(reporter);
}
template <typename T> struct PairRec {
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-09 12:47:39 +0000