rename gamma to table, since it is more general than just gamma
git-svn-id: http://skia.googlecode.com/svn/trunk@412 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/SkTableMaskFilter.cpp b/src/effects/SkTableMaskFilter.cpp
new file mode 100644
index 0000000..aea939f
--- /dev/null
+++ b/src/effects/SkTableMaskFilter.cpp
@@ -0,0 +1,127 @@
+#include "SkTableMaskFilter.h"
+
+SkTableMaskFilter::SkTableMaskFilter() {
+ for (int i = 0; i < 256; i++) {
+ fTable[i] = i;
+ }
+}
+
+SkTableMaskFilter::SkTableMaskFilter(const uint8_t table[256]) {
+ this->setTable(table);
+}
+
+SkTableMaskFilter::~SkTableMaskFilter() {}
+
+void SkTableMaskFilter::setTable(const uint8_t table[256]) {
+ memcpy(fTable, table, 256);
+}
+
+bool SkTableMaskFilter::filterMask(SkMask* dst, const SkMask& src,
+ const SkMatrix&, SkIPoint* margin) {
+ if (src.fFormat != SkMask::kA8_Format) {
+ return false;
+ }
+
+ dst->fBounds = src.fBounds;
+ dst->fRowBytes = SkAlign4(dst->fBounds.width());
+ dst->fFormat = SkMask::kA8_Format;
+ dst->fImage = NULL;
+
+ if (src.fImage) {
+ dst->fImage = SkMask::AllocImage(dst->computeImageSize());
+
+ const uint8_t* srcP = src.fImage;
+ uint8_t* dstP = dst->fImage;
+ const uint8_t* table = fTable;
+ int dstWidth = dst->fBounds.width();
+ int extraZeros = dst->fRowBytes - dstWidth;
+
+ for (int y = dst->fBounds.height() - 1; y >= 0; --y) {
+ for (int x = dstWidth - 1; x >= 0; --x) {
+ dstP[x] = table[srcP[x]];
+ }
+ srcP += src.fRowBytes;
+ // we can't just inc dstP by rowbytes, because if it has any
+ // padding between its width and its rowbytes, we need to zero those
+ // so that the bitters can read those safely if that is faster for
+ // them
+ dstP += dstWidth;
+ for (int i = extraZeros - 1; i >= 0; --i) {
+ *dstP++ = 0;
+ }
+ }
+ }
+
+ if (margin) {
+ margin->set(0, 0);
+ }
+ return true;
+}
+
+SkMask::Format SkTableMaskFilter::getFormat() {
+ return SkMask::kA8_Format;
+}
+
+void SkTableMaskFilter::flatten(SkFlattenableWriteBuffer& wb) {
+ this->INHERITED::flatten(wb);
+ wb.writePad(fTable, 256);
+}
+
+SkTableMaskFilter::SkTableMaskFilter(SkFlattenableReadBuffer& rb)
+ : INHERITED(rb) {
+ rb.read(fTable, 256);
+}
+
+SkFlattenable* SkTableMaskFilter::Factory(SkFlattenableReadBuffer& rb) {
+ return SkNEW_ARGS(SkTableMaskFilter, (rb));
+}
+
+SkFlattenable::Factory SkTableMaskFilter::getFactory() {
+ return SkTableMaskFilter::Factory;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+void SkTableMaskFilter::MakeGammaTable(uint8_t table[256], SkScalar gamma) {
+ float x = 0;
+ const float dx = 1 / 255.0f;
+ for (int i = 0; i < 256; i++) {
+ table[i] = SkPin32(SkScalarRound(powf(x, gamma) * 255), 0, 255);
+ x += dx;
+ }
+}
+
+void SkTableMaskFilter::MakeClipTable(uint8_t table[256], uint8_t min,
+ uint8_t max) {
+ if (0 == max) {
+ max = 1;
+ }
+ if (min >= max) {
+ min = max - 1;
+ }
+ SkASSERT(min < max);
+
+ SkFixed scale = (1 << 16) * 255 / (max - min);
+ memset(table, 0, min + 1);
+ for (int i = min + 1; i < max; i++) {
+ int value = SkFixedRound(scale * (i - min));
+ SkASSERT(value <= 255);
+ table[i] = value;
+ }
+ memset(table + max, 255, 256 - max);
+
+#if 0
+ int j;
+ for (j = 0; j < 256; j++) {
+ if (table[j]) {
+ break;
+ }
+ }
+ SkDebugf("%d %d start [%d]", min, max, j);
+ for (; j < 256; j++) {
+ SkDebugf(" %d", table[j]);
+ }
+ SkDebugf("\n\n");
+#endif
+}
+