static RImage *renderDGradient(unsigned width, unsigned height, int r0, int g0, int b0, int rf, int gf, int bf)
{
RImage *image, *tmp;
int j;
float a, offset;
unsigned char *ptr;
if (width == 1)
return renderVGradient(width, height, r0, g0, b0, rf, gf, bf);
else if (height == 1)
return renderHGradient(width, height, r0, g0, b0, rf, gf, bf);
image = RCreateImage(width, height, False);
if (!image) {
return NULL;
}
tmp = renderHGradient(2 * width - 1, 1, r0, g0, b0, rf, gf, bf);
if (!tmp) {
RReleaseImage(image);
return NULL;
}
ptr = tmp->data;
a = ((float)(width - 1)) / ((float)(height - 1));
width = width * 3;
/* copy the first line to the other lines with corresponding offset */
for (j = 0, offset = 0.0; j < width * height; j += width) {
memcpy(&(image->data[j]), &ptr[3 * (int)offset], width);
offset += a;
}
RReleaseImage(tmp);
return image;
}
static RImage *renderMDGradient(unsigned width, unsigned height, RColor ** colors, int count)
{
RImage *image, *tmp;
float a, offset;
int j;
unsigned char *ptr;
assert(count > 2);
if (width == 1)
return renderMVGradient(width, height, colors, count);
else if (height == 1)
return renderMHGradient(width, height, colors, count);
image = RCreateImage(width, height, False);
if (!image) {
return NULL;
}
if (count > width)
count = width;
if (count > height)
count = height;
if (count > 2)
tmp = renderMHGradient(2 * width - 1, 1, colors, count);
else
tmp = renderHGradient(2 * width - 1, 1, colors[0]->red << 8,
colors[0]->green << 8, colors[0]->blue << 8,
colors[1]->red << 8, colors[1]->green << 8, colors[1]->blue << 8);
if (!tmp) {
RReleaseImage(image);
return NULL;
}
ptr = tmp->data;
a = ((float)(width - 1)) / ((float)(height - 1));
width = width * 3;
/* copy the first line to the other lines with corresponding offset */
for (j = 0, offset = 0; j < width * height; j += width) {
memcpy(&(image->data[j]), &ptr[3 * (int)offset], width);
offset += a;
}
RReleaseImage(tmp);
return image;
}
RImage *RRenderGradient(unsigned width, unsigned height, const RColor *from, const RColor *to, RGradientStyle style)
{
switch (style) {
case RHorizontalGradient:
return renderHGradient(width, height, from->red, from->green,
from->blue, to->red, to->green, to->blue);
case RVerticalGradient:
return renderVGradient(width, height, from->red, from->green,
from->blue, to->red, to->green, to->blue);
case RDiagonalGradient:
return renderDGradient(width, height, from->red, from->green,
from->blue, to->red, to->green, to->blue);
}
assert(0);
return NULL;
}