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tdeaddons/noatun-plugins/tippercanoe/polygon.h

99 lines
2.2 KiB

#include <string.h>
template<class Pixel>
struct Bitmap {
int width, height, extra;
Pixel *data;
Bitmap(int e=0) : extra(e), data(0) { };
~Bitmap() { delete[] data; };
void size(int w,int h) {
delete[] data;
width = w;
height = h;
data = new Pixel[w*h+extra];
clear();
}
void clear() {
memset(data,0,sizeof(Pixel)*(width*height+extra));
}
};
template<class Pixel, class Combiner, int superSampleShift>
struct PolygonEngine : public Bitmap<Pixel> {
PolygonEngine() : Bitmap<Pixel>(1) { }
#define super (1<<superSampleShift)
void apply(Pixel *dest) {
Pixel sum=0;
int count = this->width*this->height;
Pixel *src = this->data;
while(count--) {
sum += *(src++);
if (sum)
*dest = Combiner::combine(sum,*dest);
dest++;
}
}
void add(Pixel color,int x,int y) {
if (y < 0) return;
if (y >= this->height) return;
if (x < 0) x = 0;
if (x > this->width) x = this->width;
this->data[x+y*this->width] += color;
}
/* Color is char[layers] */
// zwoosh, yknow, it goes... zwoosh an all these bars and lines and
// crap intersect.
Pixel colorTable[2][super+1];
void pen(Pixel color) {
for(int i=0;i<super+1;i++) {
colorTable[0][i] = color*i;
colorTable[1][i] = -(color*i);
}
}
void line(int x1,int y1,int x2,int y2) {
Pixel *colors;
if (y2 < y1) {
int temp;
temp = x2; x2 = x1; x1 = temp;
temp = y2; y2 = y1; y1 = temp;
colors = colorTable[1];
} else {
if (y1 == y2) return;
colors= colorTable[0];
}
int slope = (x1-x2 << 16)/(y1-y2);
int x = x1<<16, y = y1;
while(y < y2) {
add(colors[super-((x>>16)&(super-1))],
x>>(16+superSampleShift),y>>superSampleShift);
add(colors[(x>>16)&(super-1)],
1+(x>>(16+superSampleShift)),y>>superSampleShift);
x += slope;
y++;
}
}
void icon(double icon[][4],Pixel color,double x,double y,
double scaleX, double scaleY) {
pen(color);
x *= super;
y *= super;
scaleX *= super;
scaleY *= super;
for(int i=0;icon[i][1] != icon[i][3];i++)
line(int(icon[i][0]*scaleX+x),int(icon[i][1]*scaleY+y),
int(icon[i][2]*scaleX+x),int(icon[i][3]*scaleY+y));
}
#undef super
};