protected override unsafe void AddSurfaceRectangleToHistogram(ImageSurface surface, Gdk.Rectangle rect)
{
long[] histogramB = histogram[0];
long[] histogramG = histogram[1];
long[] histogramR = histogram[2];
int rect_right = rect.GetRight ();
for (int y = rect.Y; y <= rect.GetBottom (); ++y)
{
ColorBgra* ptr = surface.GetPointAddressUnchecked(rect.X, y);
for (int x = rect.X; x <= rect_right; ++x)
{
++histogramB[ptr->B];
++histogramG[ptr->G];
++histogramR[ptr->R];
++ptr;
}
}
}
//same as RenderRect, except the histogram is alpha-weighted instead of keeping a separate alpha channel histogram.
public unsafe void RenderRectWithAlpha(
int rad,
ImageSurface src,
ImageSurface dst,
Gdk.Rectangle rect)
{
int width = src.Width;
int height = src.Height;
int* leadingEdgeX = stackalloc int[rad + 1];
int stride = src.Stride / sizeof(ColorBgra);
// approximately (rad + 0.5)^2
int cutoff = ((rad * 2 + 1) * (rad * 2 + 1) + 2) / 4;
for (int v = 0; v <= rad; ++v)
{
for (int u = 0; u <= rad; ++u)
{
if (u * u + v * v <= cutoff)
{
leadingEdgeX[v] = u;
}
}
}
const int hLength = 256;
int* hb = stackalloc int[hLength];
int* hg = stackalloc int[hLength];
int* hr = stackalloc int[hLength];
uint hSize = (uint)(sizeof(int) * hLength);
for (int y = rect.Top; y <= rect.GetBottom (); y++)
{
SetToZero(hb, hSize);
SetToZero(hg, hSize);
SetToZero(hr, hSize);
int area = 0;
int sum = 0;
ColorBgra* ps = src.GetPointAddressUnchecked(rect.Left, y);
ColorBgra* pd = dst.GetPointAddressUnchecked(rect.Left, y);
// assert: v + y >= 0
int top = -Math.Min(rad, y);
// assert: v + y <= height - 1
int bottom = Math.Min(rad, height - 1 - y);
// assert: u + x >= 0
int left = -Math.Min(rad, rect.Left);
// assert: u + x <= width - 1
int right = Math.Min(rad, width - 1 - rect.Left);
for (int v = top; v <= bottom; ++v)
{
ColorBgra* psamp = src.GetPointAddressUnchecked(rect.Left + left, y + v);
for (int u = left; u <= right; ++u)
{
byte w = psamp->A;
if ((u * u + v * v) <= cutoff)
{
++area;
sum += w;
hb[psamp->B] += w;
hg[psamp->G] += w;
hr[psamp->R] += w;
}
++psamp;
}
}
for (int x = rect.Left; x <= rect.GetRight (); x++)
{
*pd = ApplyWithAlpha(*ps, area, sum, hb, hg, hr);
// assert: u + x >= 0
left = -Math.Min(rad, x);
// assert: u + x <= width - 1
right = Math.Min(rad + 1, width - 1 - x);
// Subtract trailing edge top half
int v = -1;
while (v >= top)
{
int u = leadingEdgeX[-v];
if (-u >= left)
{
break;
}
--v;
}
while (v >= top)
{
int u = leadingEdgeX[-v];
ColorBgra* p = unchecked(ps + (v * stride)) - u;
byte w = p->A;
hb[p->B] -= w;
hg[p->G] -= w;
hr[p->R] -= w;
sum -= w;
--area;
--v;
}
// add leading edge top half
v = -1;
while (v >= top)
{
int u = leadingEdgeX[-v];
if (u + 1 <= right)
{
break;
}
--v;
}
while (v >= top)
{
int u = leadingEdgeX[-v];
ColorBgra* p = unchecked(ps + (v * stride)) + u + 1;
byte w = p->A;
hb[p->B] += w;
hg[p->G] += w;
hr[p->R] += w;
sum += w;
++area;
--v;
}
// Subtract trailing edge bottom half
v = 0;
while (v <= bottom)
{
int u = leadingEdgeX[v];
if (-u >= left)
{
break;
}
++v;
}
while (v <= bottom)
{
int u = leadingEdgeX[v];
ColorBgra* p = ps + v * stride - u;
byte w = p->A;
hb[p->B] -= w;
hg[p->G] -= w;
hr[p->R] -= w;
sum -= w;
--area;
++v;
}
// add leading edge bottom half
v = 0;
while (v <= bottom)
{
int u = leadingEdgeX[v];
if (u + 1 <= right)
{
break;
}
++v;
}
while (v <= bottom)
{
int u = leadingEdgeX[v];
ColorBgra* p = ps + v * stride + u + 1;
byte w = p->A;
hb[p->B] += w;
hg[p->G] += w;
hr[p->R] += w;
sum += w;
++area;
++v;
}
++ps;
++pd;
}
}
}
public void Invert (Gdk.Rectangle rect)
{
for (int y = rect.Y; y <= rect.GetBottom (); ++y) {
for (int x = rect.X; x <= rect.GetRight (); ++x) {
Invert (x, y);
}
}
}
private unsafe static void RenderClouds(ImageSurface surface, Gdk.Rectangle rect, int scale, byte seed, double power, ColorBgra colorFrom, ColorBgra colorTo)
{
int w = surface.Width;
int h = surface.Height;
for (int y = rect.Top; y <= rect.GetBottom (); ++y)
{
ColorBgra* ptr = surface.GetPointAddressUnchecked(0, y - rect.Top);
int dy = 2 * y - h;
for (int x = rect.Left; x <= rect.GetRight (); ++x)
{
int dx = 2 * x - w;
double val = 0;
double mult = 1;
int div = scale;
for (int i = 0; i < 12 && mult > 0.03 && div > 0; ++i)
{
double dxr = 65536 + (double)dx / (double)div;
double dyr = 65536 + (double)dy / (double)div;
int dxd = (int)dxr;
int dyd = (int)dyr;
dxr -= dxd;
dyr -= dyd;
double noise = Noise(
unchecked((byte)dxd),
unchecked((byte)dyd),
dxr, //(double)dxr / div,
dyr, //(double)dyr / div,
(byte)(seed ^ i));
val += noise * mult;
div /= 2;
mult *= power;
}
*ptr = ColorBgra.Lerp(colorFrom, colorTo, (val + 1) / 2);
++ptr;
}
}
}
public void Set (Gdk.Rectangle rect, bool newValue)
{
for (int y = rect.Y; y <= rect.GetBottom (); ++y) {
for (int x = rect.X; x <= rect.GetRight (); ++x) {
Set (x, y, newValue);
}
}
}