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#include <u.h>
#include <libc.h>
#include <thread.h>
#include <draw.h>
#include <memdraw.h>
#include <geometry.h>
#include "libobj/obj.h"
#include "graphics.h"
#include "internal.h"
/*
* uv-coords belong to the 1st quadrant (v grows bottom-up),
* hence the need to reverse the v coord.
*/
static Point
uv2tp(Point2 uv, Memimage *i)
{
assert(uv.x >= 0 && uv.x <= 1 && uv.y >= 0 && uv.y <= 1);
return Pt(uv.x*Dx(i->r), (1 - uv.y)*Dy(i->r));
}
static Color
ul2col(ulong l)
{
Color c;
c.a = (l & 0xff)/255.0;
c.b = (l>>8 & 0xff)/255.0;
c.g = (l>>16 & 0xff)/255.0;
c.r = (l>>24 & 0xff)/255.0;
return c;
}
static Color
cbuf2col(uchar b[4])
{
Color c;
c.a = b[0] / 255.0;
c.b = b[1] / 255.0;
c.g = b[2] / 255.0;
c.r = b[3] / 255.0;
return c;
}
static Color
_memreadcolor(Memimage *i, Point sp)
{
uchar cbuf[4];
switch(i->chan){
case RGB24:
unloadmemimage(i, rectaddpt(UR, sp), cbuf+1, sizeof cbuf - 1);
cbuf[0] = 0xFF;
break;
case RGBA32:
unloadmemimage(i, rectaddpt(UR, sp), cbuf, sizeof cbuf);
break;
case XRGB32:
unloadmemimage(i, rectaddpt(UR, sp), cbuf, sizeof cbuf);
memmove(cbuf+1, cbuf, 3);
cbuf[0] = 0xFF;
break;
}
return cbuf2col(cbuf);
}
/*
* nearest-neighbour sampler
*/
Color
neartexsampler(Memimage *i, Point2 uv)
{
return _memreadcolor(i, uv2tp(uv, i));
}
/*
* bilinear sampler
*/
Color
bilitexsampler(Memimage *i, Point2 uv)
{
Rectangle r;
Color c1, c2;
r = rectaddpt(UR, uv2tp(uv, i));
if(r.min.x < i->r.min.x){
r.min.x++;
r.max.x++;
}if(r.min.y < i->r.min.y){
r.min.y++;
r.max.y++;
}if(r.max.x >= i->r.max.x){
r.min.x--;
r.max.x--;
}if(r.max.y >= i->r.max.y){
r.min.y--;
r.max.y--;
}
c1 = lerp3(_memreadcolor(i, r.min), _memreadcolor(i, Pt(r.max.x, r.min.y)), 0.5);
c2 = lerp3(_memreadcolor(i, Pt(r.min.x, r.max.y)), _memreadcolor(i, r.max), 0.5);
return lerp3(c1, c2, 0.5);
}
Color
texture(Memimage *i, Point2 uv, Color(*sampler)(Memimage*,Point2))
{
return sampler(i, uv);
}
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