Commit 8b89f185 authored by Sven Neumann's avatar Sven Neumann Committed by Sven Neumann

applied some simple but effective optimizations to

2001-08-19  Sven Neumann  <sven@gimp.org>

	* pixops/pixops.c: applied some simple but effective optimizations
	to pixops_composite_nearest() and pixops_composite_color_nearest().
parent 112eb9b2
2001-08-19 Sven Neumann <sven@gimp.org>
* pixops/pixops.c: applied some simple but effective optimizations
to pixops_composite_nearest() and pixops_composite_color_nearest().
2001-08-07 Sven Neumann <sven@gimp.org>
* gdk-pixbuf.c (gdk_pixbuf_fill): a comment asked to optimize this
......
......@@ -176,37 +176,39 @@ pixops_composite_nearest (guchar *dest_buf,
else
a0 = overall_alpha;
if (dest_has_alpha)
{
unsigned int w0 = 0xff * a0;
unsigned int w1 = (0xff - a0) * dest[3];
unsigned int w = w0 + w1;
switch (a0)
{
case 0:
break;
case 255:
dest[0] = p[0];
dest[1] = p[1];
dest[2] = p[2];
if (dest_has_alpha)
dest[3] = 0xff;
break;
default:
if (dest_has_alpha)
{
unsigned int w0 = 0xff * a0;
unsigned int w1 = (0xff - a0) * dest[3];
unsigned int w = w0 + w1;
if (w != 0)
{
dest[0] = (w0 * p[0] + w1 * dest[0]) / w;
dest[1] = (w0 * p[1] + w1 * dest[1]) / w;
dest[2] = (w0 * p[2] + w1 * dest[2]) / w;
dest[3] = w / 0xff;
}
else
{
dest[0] = 0;
dest[1] = 0;
dest[2] = 0;
dest[3] = 0;
}
}
else
{
dest[0] = (a0 * p[0] + (0xff - a0) * dest[0]) / 0xff;
dest[1] = (a0 * p[1] + (0xff - a0) * dest[1]) / 0xff;
dest[2] = (a0 * p[2] + (0xff - a0) * dest[2]) / 0xff;
if (dest_channels == 4)
dest[3] = 0xff;
}
}
else
{
unsigned int a1 = 0xff - a0;
dest[0] = (a0 * p[0] + a1 * dest[0]) / 0xff;
dest[1] = (a0 * p[1] + a1 * dest[1]) / 0xff;
dest[2] = (a0 * p[2] + a1 * dest[2]) / 0xff;
}
break;
}
dest += dest_channels;
x += x_step;
}
......@@ -283,31 +285,48 @@ pixops_composite_color_nearest (guchar *dest_buf,
else
a0 = overall_alpha;
if (a0 == 255)
{
switch (a0)
{
case 0:
if (((j + check_x) >> check_shift) & 1)
{
dest[0] = r2;
dest[1] = g2;
dest[2] = b2;
}
else
{
dest[0] = r1;
dest[1] = g1;
dest[2] = b1;
}
break;
case 255:
dest[0] = p[0];
dest[1] = p[1];
dest[2] = p[2];
}
else
if (((j + check_x) >> check_shift) & 1)
{
tmp = ((int) p[0] - r2) * a0;
dest[0] = r2 + ((tmp + (tmp >> 8) + 0x80) >> 8);
tmp = ((int) p[1] - g2) * a0;
dest[1] = g2 + ((tmp + (tmp >> 8) + 0x80) >> 8);
tmp = ((int) p[2] - b2) * a0;
dest[2] = b2 + ((tmp + (tmp >> 8) + 0x80) >> 8);
}
else
{
tmp = ((int) p[0] - r1) * a0;
dest[0] = r1 + ((tmp + (tmp >> 8) + 0x80) >> 8);
tmp = ((int) p[1] - g1) * a0;
dest[1] = g1 + ((tmp + (tmp >> 8) + 0x80) >> 8);
tmp = ((int) p[2] - b1) * a0;
dest[2] = b1 + ((tmp + (tmp >> 8) + 0x80) >> 8);
}
break;
default:
if (((j + check_x) >> check_shift) & 1)
{
tmp = ((int) p[0] - r2) * a0;
dest[0] = r2 + ((tmp + (tmp >> 8) + 0x80) >> 8);
tmp = ((int) p[1] - g2) * a0;
dest[1] = g2 + ((tmp + (tmp >> 8) + 0x80) >> 8);
tmp = ((int) p[2] - b2) * a0;
dest[2] = b2 + ((tmp + (tmp >> 8) + 0x80) >> 8);
}
else
{
tmp = ((int) p[0] - r1) * a0;
dest[0] = r1 + ((tmp + (tmp >> 8) + 0x80) >> 8);
tmp = ((int) p[1] - g1) * a0;
dest[1] = g1 + ((tmp + (tmp >> 8) + 0x80) >> 8);
tmp = ((int) p[2] - b1) * a0;
dest[2] = b1 + ((tmp + (tmp >> 8) + 0x80) >> 8);
}
break;
}
if (dest_channels == 4)
dest[3] = 0xff;
......
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