speedup mipmap building
mipmap_build benchmark:
before: 3.36ms
after: 2.20ms
BUG=skia:
Review URL: https://codereview.chromium.org/873393002
diff --git a/src/core/SkMipMap.cpp b/src/core/SkMipMap.cpp
index 4e7fc4b..9e0e5e1 100644
--- a/src/core/SkMipMap.cpp
+++ b/src/core/SkMipMap.cpp
@@ -9,32 +9,54 @@
#include "SkBitmap.h"
#include "SkColorPriv.h"
-static void downsampleby2_proc32(SkBitmap* dst, int x, int y,
- const SkBitmap& src) {
+static void downsample32_nocheck(void* dst, int, int, const void* srcPtr, const SkBitmap& srcBM) {
+ const uint32_t* p = static_cast<const uint32_t*>(srcPtr);
+ const uint32_t* baseP = p;
+ uint32_t c, ag, rb;
+
+ c = *p; ag = (c >> 8) & 0xFF00FF; rb = c & 0xFF00FF;
+ p += 1;
+
+ c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF;
+
+ p = baseP;
+ p += srcBM.rowBytes() >> 2;
+
+ c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF;
+ p += 1;
+
+ c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF;
+
+ *(uint32_t*)dst = ((rb >> 2) & 0xFF00FF) | ((ag << 6) & 0xFF00FF00);
+}
+
+static void downsample32_check(void* dst, int x, int y, const void* srcPtr, const SkBitmap& srcBM) {
+ const uint32_t* p = static_cast<const uint32_t*>(srcPtr);
+ const uint32_t* baseP = p;
+
x <<= 1;
y <<= 1;
- const SkPMColor* p = src.getAddr32(x, y);
- const SkPMColor* baseP = p;
+ SkASSERT(srcBM.getAddr32(x, y) == p);
+
SkPMColor c, ag, rb;
c = *p; ag = (c >> 8) & 0xFF00FF; rb = c & 0xFF00FF;
- if (x < src.width() - 1) {
+ if (x < srcBM.width() - 1) {
p += 1;
}
c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF;
p = baseP;
- if (y < src.height() - 1) {
- p += src.rowBytes() >> 2;
+ if (y < srcBM.height() - 1) {
+ p += srcBM.rowBytes() >> 2;
}
c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF;
- if (x < src.width() - 1) {
+ if (x < srcBM.width() - 1) {
p += 1;
}
c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF;
- *dst->getAddr32(x >> 1, y >> 1) =
- ((rb >> 2) & 0xFF00FF) | ((ag << 6) & 0xFF00FF00);
+ *((uint32_t*)dst) = ((rb >> 2) & 0xFF00FF) | ((ag << 6) & 0xFF00FF00);
}
static inline uint32_t expand16(U16CPU c) {
@@ -47,31 +69,33 @@
return (c & ~SK_G16_MASK_IN_PLACE) | ((c >> 16) & SK_G16_MASK_IN_PLACE);
}
-static void downsampleby2_proc16(SkBitmap* dst, int x, int y,
- const SkBitmap& src) {
+static void downsample16(void* dst, int x, int y, const void* srcPtr, const SkBitmap& srcBM) {
+ const uint16_t* p = static_cast<const uint16_t*>(srcPtr);
+ const uint16_t* baseP = p;
+
x <<= 1;
y <<= 1;
- const uint16_t* p = src.getAddr16(x, y);
- const uint16_t* baseP = p;
- SkPMColor c;
+ SkASSERT(srcBM.getAddr16(x, y) == p);
+
+ SkPMColor c;
c = expand16(*p);
- if (x < src.width() - 1) {
+ if (x < srcBM.width() - 1) {
p += 1;
}
c += expand16(*p);
p = baseP;
- if (y < src.height() - 1) {
- p += src.rowBytes() >> 1;
+ if (y < srcBM.height() - 1) {
+ p += srcBM.rowBytes() >> 1;
}
c += expand16(*p);
- if (x < src.width() - 1) {
+ if (x < srcBM.width() - 1) {
p += 1;
}
c += expand16(*p);
- *dst->getAddr16(x >> 1, y >> 1) = (uint16_t)pack16(c >> 2);
+ *((uint16_t*)dst) = (uint16_t)pack16(c >> 2);
}
static uint32_t expand4444(U16CPU c) {
@@ -82,31 +106,33 @@
return (c & 0xF0F) | ((c >> 12) & ~0xF0F);
}
-static void downsampleby2_proc4444(SkBitmap* dst, int x, int y,
- const SkBitmap& src) {
+static void downsample4444(void* dst, int x, int y, const void* srcPtr, const SkBitmap& srcBM) {
+ const uint16_t* p = static_cast<const uint16_t*>(srcPtr);
+ const uint16_t* baseP = p;
+
x <<= 1;
y <<= 1;
- const uint16_t* p = src.getAddr16(x, y);
- const uint16_t* baseP = p;
- uint32_t c;
+ SkASSERT(srcBM.getAddr16(x, y) == p);
+
+ uint32_t c;
c = expand4444(*p);
- if (x < src.width() - 1) {
+ if (x < srcBM.width() - 1) {
p += 1;
}
c += expand4444(*p);
p = baseP;
- if (y < src.height() - 1) {
- p += src.rowBytes() >> 1;
+ if (y < srcBM.height() - 1) {
+ p += srcBM.rowBytes() >> 1;
}
c += expand4444(*p);
- if (x < src.width() - 1) {
+ if (x < srcBM.width() - 1) {
p += 1;
}
c += expand4444(*p);
- *dst->getAddr16(x >> 1, y >> 1) = (uint16_t)collaps4444(c >> 2);
+ *((uint16_t*)dst) = (uint16_t)collaps4444(c >> 2);
}
size_t SkMipMap::AllocLevelsSize(int levelCount, size_t pixelSize) {
@@ -120,21 +146,26 @@
return sk_64_asS32(size);
}
+typedef void SkDownSampleProc(void*, int x, int y, const void* srcPtr, const SkBitmap& srcBM);
+
SkMipMap* SkMipMap::Build(const SkBitmap& src, SkDiscardableFactoryProc fact) {
- void (*proc)(SkBitmap* dst, int x, int y, const SkBitmap& src);
+ SkDownSampleProc* proc_nocheck, *proc_check;
const SkColorType ct = src.colorType();
const SkAlphaType at = src.alphaType();
switch (ct) {
case kRGBA_8888_SkColorType:
case kBGRA_8888_SkColorType:
- proc = downsampleby2_proc32;
+ proc_check = downsample32_check;
+ proc_nocheck = downsample32_nocheck;
break;
case kRGB_565_SkColorType:
- proc = downsampleby2_proc16;
+ proc_check = downsample16;
+ proc_nocheck = proc_check;
break;
case kARGB_4444_SkColorType:
- proc = downsampleby2_proc4444;
+ proc_check = downsample4444;
+ proc_nocheck = proc_check;
break;
default:
return NULL; // don't build mipmaps for any other colortypes (yet)
@@ -208,11 +239,37 @@
dstBM.installPixels(SkImageInfo::Make(width, height, ct, at), addr, rowBytes);
srcBM.lockPixels();
- for (int y = 0; y < height; y++) {
+ const int widthEven = width & ~1;
+ const int heightEven = height & ~1;
+ const size_t pixelSize = srcBM.info().bytesPerPixel();
+
+ const void* srcBasePtr = srcBM.getPixels();
+ void* dstBasePtr = dstBM.getPixels();
+ for (int y = 0; y < heightEven; y++) {
+ const void* srcPtr = srcBasePtr;
+ void* dstPtr = dstBasePtr;
+ for (int x = 0; x < widthEven; x++) {
+ proc_nocheck(dstPtr, x, y, srcPtr, srcBM);
+ srcPtr = (char*)srcPtr + pixelSize * 2;
+ dstPtr = (char*)dstPtr + pixelSize;
+ }
+ if (width & 1) {
+ proc_check(dstPtr, widthEven, y, srcPtr, srcBM);
+ }
+
+ srcBasePtr = (char*)srcBasePtr + srcBM.rowBytes() * 2;
+ dstBasePtr = (char*)dstBasePtr + dstBM.rowBytes();
+ }
+ if (height & 1) {
+ const void* srcPtr = srcBasePtr;
+ void* dstPtr = dstBasePtr;
for (int x = 0; x < width; x++) {
- proc(&dstBM, x, y, srcBM);
+ proc_check(dstPtr, x, heightEven, srcPtr, srcBM);
+ srcPtr = (char*)srcPtr + pixelSize * 2;
+ dstPtr = (char*)dstPtr + pixelSize;
}
}
+
srcBM.unlockPixels();
srcBM = dstBM;