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Commit d243cf67 authored by Mike Reed's avatar Mike Reed
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pad the top/left of the sum buffer with zeros (so we can use it correctly)

parent b7ace96e
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Showing with 83 additions and 51 deletions
src/effects/SkBlurMask.cpp
View file @ d243cf67
......@@ -18,33 +18,65 @@
#include "SkBlurMask.h"
#include "SkTemplates.h"
static void build_sum_buffer(uint32_t dst[], int w, int h, const uint8_t src[], int srcRB)
{
SkASSERT(srcRB >= w);
#if 0
static void dump_sum_buffer(const uint32_t sum[], const int w, const int h) {
printf("---- sum buffer\n");
for (int y = 0; y <= h; y++) {
for (int x = 0; x <= w; x++) {
printf(" %5d", sum[x]);
}
printf("\n");
sum += w+1;
}
}
#else
#define dump_sum_buffer(sum, w, h)
#endif
/** The sum buffer is an array of u32 to hold the accumulated sum of all of the
src values at their position, plus all values above and to the left.
When we sample into this buffer, we need an initial row and column of 0s,
so we have an index correspondence as follows:
src[i, j] == sum[i+1, j+1]
sum[0, j] == sum[i, 0] == 0
We assume that the sum buffer's stride == its width
*/
static void build_sum_buffer(uint32_t sum[], int srcW, int srcH, const uint8_t src[], int srcRB) {
int sumW = srcW + 1;
SkASSERT(srcRB >= srcW);
// mod srcRB so we can apply it after each row
srcRB -= w;
srcRB -= srcW;
int x, y;
// zero out the top row and column
memset(sum, 0, sumW * sizeof(sum[0]));
sum += sumW;
// special case first row
uint32_t X = 0;
for (x = w - 1; x >= 0; --x)
*sum++ = 0; // initialze the first column to 0
for (x = srcW - 1; x >= 0; --x)
{
X = *src++ + X;
*dst++ = X;
*sum++ = X;
}
src += srcRB;
// now do the rest of the rows
for (y = h - 1; y > 0; --y)
for (y = srcH - 1; y > 0; --y)
{
uint32_t L = 0;
uint32_t C = 0;
for (x = w - 1; x >= 0; --x)
*sum++ = 0; // initialze the first column to 0
for (x = srcW - 1; x >= 0; --x)
{
uint32_t T = dst[-w];
uint32_t T = sum[-sumW];
X = *src++ + L + T - C;
*dst++ = X;
*sum++ = X;
L = X;
C = T;
}
......@@ -52,36 +84,36 @@ static void build_sum_buffer(uint32_t dst[], int w, int h, const uint8_t src[],
}
}
static void apply_kernel(uint8_t dst[], int rx, int ry, const uint32_t src[], int sw, int sh)
{
/* sw and sh are the width and height of the src. Since the sum buffer
matches that, but has an extra row and col at the beginning (with zeros),
we can just use sw and sh as our "max" values for pinning coordinates
when sampling into sum[][]
*/
static void apply_kernel(uint8_t dst[], int rx, int ry, const uint32_t sum[],
int sw, int sh) {
uint32_t scale = (1 << 24) / ((2*rx + 1)*(2*ry + 1));
int rowBytes = sw;
int sumStride = sw + 1;
int dw = sw + 2*rx;
int dh = sh + 2*ry;
sw -= 1; // now it is max_x
sh -= 1; // now it is max_y
int prev_y = -2*ry;
int next_y = 1;
int prev_y = -ry - 1 -ry;
int next_y = ry -ry;
for (int y = 0; y < dh; y++) {
int py = SkClampPos(prev_y) * sumStride;
int ny = SkFastMin32(next_y, sh) * sumStride;
for (int y = 0; y < dh; y++)
{
int py = SkClampPos(prev_y) * rowBytes;
int ny = SkFastMin32(next_y, sh) * rowBytes;
int prev_x = -rx - 1 -rx;
int next_x = rx -rx;
int prev_x = -2*rx;
int next_x = 1;
for (int x = 0; x < dw; x++)
{
for (int x = 0; x < dw; x++) {
int px = SkClampPos(prev_x);
int nx = SkFastMin32(next_x, sw);
uint32_t sum = src[px+py] + src[nx+ny] - src[nx+py] - src[px+ny];
*dst++ = SkToU8(sum * scale >> 24);
uint32_t tmp = sum[px+py] + sum[nx+ny] - sum[nx+py] - sum[px+ny];
*dst++ = SkToU8(tmp * scale >> 24);
prev_x += 1;
next_x += 1;
......@@ -91,8 +123,13 @@ static void apply_kernel(uint8_t dst[], int rx, int ry, const uint32_t src[], in
}
}
static void apply_kernel_interp(uint8_t dst[], int rx, int ry, const uint32_t src[], int sw, int sh, U8CPU outer_weight)
{
/* sw and sh are the width and height of the src. Since the sum buffer
matches that, but has an extra row and col at the beginning (with zeros),
we can just use sw and sh as our "max" values for pinning coordinates
when sampling into sum[][]
*/
static void apply_kernel_interp(uint8_t dst[], int rx, int ry,
const uint32_t sum[], int sw, int sh, U8CPU outer_weight) {
SkASSERT(rx > 0 && ry > 0);
SkASSERT(outer_weight <= 255);
......@@ -105,38 +142,33 @@ static void apply_kernel_interp(uint8_t dst[], int rx, int ry, const uint32_t sr
uint32_t outer_scale = (outer_weight << 16) / ((2*rx + 1)*(2*ry + 1));
uint32_t inner_scale = (inner_weight << 16) / ((2*rx - 1)*(2*ry - 1));
int rowBytes = sw;
int sumStride = sw + 1;
int dw = sw + 2*rx;
int dh = sh + 2*ry;
sw -= 1; // now it is max_x
sh -= 1; // now it is max_y
int prev_y = -2*ry;
int next_y = 1;
int prev_y = -ry - 1 -ry;
int next_y = ry -ry;
for (int y = 0; y < dh; y++) {
int py = SkClampPos(prev_y) * sumStride;
int ny = SkFastMin32(next_y, sh) * sumStride;
for (int y = 0; y < dh; y++)
{
int py = SkClampPos(prev_y) * rowBytes;
int ny = SkFastMin32(next_y, sh) * rowBytes;
int ipy = SkClampPos(prev_y + 1) * rowBytes;
int iny = SkClampMax(next_y - 1, sh) * rowBytes;
int ipy = SkClampPos(prev_y + 1) * sumStride;
int iny = SkClampMax(next_y - 1, sh) * sumStride;
int prev_x = -rx - 1 -rx;
int next_x = rx -rx;
int prev_x = -2*rx;
int next_x = 1;
for (int x = 0; x < dw; x++)
{
for (int x = 0; x < dw; x++) {
int px = SkClampPos(prev_x);
int nx = SkFastMin32(next_x, sw);
int ipx = SkClampPos(prev_x + 1);
int inx = SkClampMax(next_x - 1, sw);
uint32_t outer_sum = src[px+py] + src[nx+ny] - src[nx+py] - src[px+ny];
uint32_t inner_sum = src[ipx+ipy] + src[inx+iny] - src[inx+ipy] - src[ipx+iny];
uint32_t outer_sum = sum[px+py] + sum[nx+ny] - sum[nx+py] - sum[px+ny];
uint32_t inner_sum = sum[ipx+ipy] + sum[inx+iny] - sum[inx+ipy] - sum[ipx+iny];
*dst++ = SkToU8((outer_sum * outer_scale + inner_sum * inner_scale) >> 24);
prev_x += 1;
......@@ -172,8 +204,7 @@ static void merge_src_with_blur(uint8_t dst[], int dstRB,
static void clamp_with_orig(uint8_t dst[], int dstRowBytes,
const uint8_t src[], int srcRowBytes,
int sw, int sh,
SkBlurMask::Style style)
{
SkBlurMask::Style style) {
int x;
while (--sh >= 0) {
switch (style) {
......@@ -252,10 +283,11 @@ bool SkBlurMask::Blur(SkMask* dst, const SkMask& src,
// build the blurry destination
{
SkAutoTMalloc<uint32_t> storage(sw * sh);
SkAutoTMalloc<uint32_t> storage((sw + 1) * (sh + 1));
uint32_t* sumBuffer = storage.get();
build_sum_buffer(sumBuffer, sw, sh, sp, src.fRowBytes);
dump_sum_buffer(sumBuffer, sw, sh);
if (outer_weight == 255)
apply_kernel(dp, rx, ry, sumBuffer, sw, sh);
else
......
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