static void PrepareVerticalMinMax(int width, int height, int radius, LimitMinMax[] limitMinMax)
{
int heightMinus1 = height - 1;
for (int y = height - 1; y >= 0; --y)
{
limitMinMax[y] = new LimitMinMax(
min(y + radius + 1, heightMinus1) * width,
max(y - radius, 0) * width);
}
}
//------------------------------------------------
static void PrepareHorizontalMinMax(int width, int radius, LimitMinMax[] limitMinMax)
{
int widthMinus1 = width - 1;
for (int x = width - 1; x >= 0; --x)
{
limitMinMax[x] = new LimitMinMax(
min(x + radius + 1, widthMinus1),
max(x - radius, 0));
}
}
static void PrepareVerticalMinMax(int width, int height, int radius, LimitMinMax[] limitMinMax)
{
int heightMinus1 = height - 1;
for (int y = height - 1; y >= 0; --y)
{
limitMinMax[y] = new LimitMinMax(
min(y + radius + 1, heightMinus1) * width,
max(y - radius, 0) * width);
}
}
//------------------------------------------------
static void PrepareHorizontalMinMax(int width, int radius, LimitMinMax[] limitMinMax)
{
int widthMinus1 = width - 1;
for (int x = width - 1; x >= 0; --x)
{
limitMinMax[x] = new LimitMinMax(
min(x + radius + 1, widthMinus1),
max(x - radius, 0));
}
}
public static void FastBlur32ARGB(int[] srcBuffer,
int[] dest,
int srcImageWidth,
int srcImageHeight,
int radius)
{
if (srcImageWidth < 1)
{
return;
}
//---------------------------------------------
//assign dimension info and copy buffer
int width = srcImageWidth;
int height = srcImageHeight;
int wh = width * height;
var r_buffer = new byte[wh];
var g_buffer = new byte[wh];
var b_buffer = new byte[wh];
var a_buffer = new byte[wh];
int p1, p2;
LimitMinMax[] limitMinMax = new LimitMinMax[max(width, height)];
//------------------------------
//look up table : depends on radius,
var dvLookup = PrepareLookupTable(radius);
//------------------------------
PrepareHorizontalMinMax(width, radius, limitMinMax);
int px_row_head = 0;
int pixel_index = 0;
for (int y = 0; y < height; y++)
{
// blur horizontal
int rsum, gsum, bsum, asum;
CalculateSumARGBHorizontal(srcBuffer, width, pixel_index, radius, out rsum, out gsum, out bsum, out asum);
for (int x = 0; x < width; x++)
{
r_buffer[pixel_index] = dvLookup[rsum];
g_buffer[pixel_index] = dvLookup[gsum];
b_buffer[pixel_index] = dvLookup[bsum];
a_buffer[pixel_index] = dvLookup[asum];
LimitMinMax lim = limitMinMax[x];
p1 = srcBuffer[px_row_head + lim.Min];
p2 = srcBuffer[px_row_head + lim.Max];
rsum += ((p1 >> R_SHIFT) & 0xff) - ((p2 >> R_SHIFT) & 0xff);
gsum += ((p1 >> G_SHIFT) & 0xff) - ((p2 >> G_SHIFT) & 0xff);
bsum += ((p1 >> B_SHIFT) & 0xff) - ((p2 >> B_SHIFT) & 0xff);
asum += ((p1 >> A_SHIFT) & 0xff) - ((p2 >> A_SHIFT) & 0xff);
pixel_index++;
}
//go next row
px_row_head += width;
}
PrepareVerticalMinMax(width, height, radius, limitMinMax);
//-------------------------------------------------------------------
for (int x = 0; x < width; x++)
{
// blur vertical
int rsum, gsum, bsum, asum;
rsum = gsum = bsum = asum = 0;
//-----------------------------
int yp = -radius * width;
for (int i = -radius; i <= 0; ++i)
{
pixel_index = x;
rsum += r_buffer[pixel_index];
gsum += g_buffer[pixel_index];
bsum += b_buffer[pixel_index];
asum += a_buffer[pixel_index];
yp += width;
}
for (int i = 1; i <= radius; ++i)
{
pixel_index = yp + x;
rsum += r_buffer[pixel_index];
gsum += g_buffer[pixel_index];
bsum += b_buffer[pixel_index];
asum += a_buffer[pixel_index];
yp += width;
}
//-----------------------------
pixel_index = x;
for (int y = 0; y < height; y++)
{
//assign pixel value here
dest[pixel_index] = (int)((uint)(dvLookup[rsum] << R_SHIFT) |
(uint)(dvLookup[gsum] << G_SHIFT) |
(uint)(dvLookup[bsum] << B_SHIFT) |
unchecked ((uint)(dvLookup[asum] << A_SHIFT)));
var limit = limitMinMax[y];
p1 = x + limit.Min;
p2 = x + limit.Max;
rsum += r_buffer[p1] - r_buffer[p2]; //diff between 2 pixels
gsum += g_buffer[p1] - g_buffer[p2]; //diff between 2 pixels
bsum += b_buffer[p1] - b_buffer[p2]; //diff between 2 pixels
asum += a_buffer[p1] - a_buffer[p2];
pixel_index += width;
}
}
}
public static void FastBlur32ARGB(int[] srcBuffer,
int[] dest,
int srcImageWidth,
int srcImageHeight,
int radius)
{
if (srcImageWidth < 1)
{
return;
}
//---------------------------------------------
//assign dimension info and copy buffer
int width = srcImageWidth;
int height = srcImageHeight;
int wh = width * height;
var r_buffer = new byte[wh];
var g_buffer = new byte[wh];
var b_buffer = new byte[wh];
var a_buffer = new byte[wh];
int p1, p2;
LimitMinMax[] limitMinMax = new LimitMinMax[max(width, height)];
//------------------------------
//look up table : depends on radius,
var dvLookup = PrepareLookupTable(radius);
//------------------------------
PrepareHorizontalMinMax(width, radius, limitMinMax);
int px_row_head = 0;
int pixel_index = 0;
for (int y = 0; y < height; y++)
{
// blur horizontal
int rsum, gsum, bsum, asum;
CalculateSumARGBHorizontal(srcBuffer, width, pixel_index, radius, out rsum, out gsum, out bsum, out asum);
for (int x = 0; x < width; x++)
{
r_buffer[pixel_index] = dvLookup[rsum];
g_buffer[pixel_index] = dvLookup[gsum];
b_buffer[pixel_index] = dvLookup[bsum];
a_buffer[pixel_index] = dvLookup[asum];
LimitMinMax lim = limitMinMax[x];
p1 = srcBuffer[px_row_head + lim.Min];
p2 = srcBuffer[px_row_head + lim.Max];
rsum += ((p1 >> R_SHIFT) & 0xff) - ((p2 >> R_SHIFT) & 0xff);
gsum += ((p1 >> G_SHIFT) & 0xff) - ((p2 >> G_SHIFT) & 0xff);
bsum += ((p1 >> B_SHIFT) & 0xff) - ((p2 >> B_SHIFT) & 0xff);
asum += ((p1 >> A_SHIFT) & 0xff) - ((p2 >> A_SHIFT) & 0xff);
pixel_index++;
}
//go next row
px_row_head += width;
}
PrepareVerticalMinMax(width, height, radius, limitMinMax);
//-------------------------------------------------------------------
for (int x = 0; x < width; x++)
{
// blur vertical
int rsum, gsum, bsum, asum;
rsum = gsum = bsum = asum = 0;
//-----------------------------
int yp = -radius * width;
for (int i = -radius; i <= 0; ++i)
{
pixel_index = x;
rsum += r_buffer[pixel_index];
gsum += g_buffer[pixel_index];
bsum += b_buffer[pixel_index];
asum += a_buffer[pixel_index];
yp += width;
}
for (int i = 1; i <= radius; ++i)
{
pixel_index = yp + x;
rsum += r_buffer[pixel_index];
gsum += g_buffer[pixel_index];
bsum += b_buffer[pixel_index];
asum += a_buffer[pixel_index];
yp += width;
}
//-----------------------------
pixel_index = x;
for (int y = 0; y < height; y++)
{
//assign pixel value here
dest[pixel_index] = (int)((uint)(dvLookup[rsum] << R_SHIFT) |
(uint)(dvLookup[gsum] << G_SHIFT) |
(uint)(dvLookup[bsum] << B_SHIFT) |
unchecked((uint)(dvLookup[asum] << A_SHIFT)));
var limit = limitMinMax[y];
p1 = x + limit.Min;
p2 = x + limit.Max;
rsum += r_buffer[p1] - r_buffer[p2]; //diff between 2 pixels
gsum += g_buffer[p1] - g_buffer[p2]; //diff between 2 pixels
bsum += b_buffer[p1] - b_buffer[p2]; //diff between 2 pixels
asum += a_buffer[p1] - a_buffer[p2];
pixel_index += width;
}
}
}
