#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"

static void
framebufctl_draw(Framebufctl *ctl, Image *dst)
{
	Framebuf *fb;

	qlock(ctl);
	fb = ctl->getfb(ctl);
	loadimage(dst, rectaddpt(fb->r, dst->r.min), (uchar*)fb->cb, Dx(fb->r)*Dy(fb->r)*4);
	qunlock(ctl);
}

static void
framebufctl_upscaledraw(Framebufctl *ctl, Image *dst, Point scale)
{
	Framebuf *fb;
	Rectangle blkr;
	Point sp, dp;
	ulong *blk;
	int i;

	blk = emalloc(scale.x*scale.y*4);
	blkr = Rect(0,0,scale.x,scale.y);

	qlock(ctl);
	fb = ctl->getfb(ctl);
	for(sp.y = fb->r.min.y, dp.y = dst->r.min.y; sp.y < fb->r.max.y; sp.y++, dp.y += scale.y)
		for(sp.x = fb->r.min.x, dp.x = dst->r.min.x; sp.x < fb->r.max.x; sp.x++, dp.x += scale.x){
			for(i = 0; i < scale.x*scale.y; i++)
				blk[i] = fb->cb[Dx(fb->r)*sp.y + sp.x];
			loadimage(dst, rectaddpt(blkr, dp), (uchar*)blk, scale.x*scale.y*4);
		}
	qunlock(ctl);
	free(blk);
}

static void
framebufctl_memdraw(Framebufctl *ctl, Memimage *dst)
{
	Framebuf *fb;

	qlock(ctl);
	fb = ctl->getfb(ctl);
	loadmemimage(dst, dst->r, (uchar*)fb->cb, Dx(fb->r)*Dy(fb->r)*4);
	qunlock(ctl);
}

static void
framebufctl_upscalememdraw(Framebufctl *ctl, Memimage *dst, Point scale)
{
	Framebuf *fb;
	Rectangle blkr;
	Point sp, dp;
	ulong *blk;
	int i;

	blk = emalloc(scale.x*scale.y*4);
	blkr = Rect(0,0,scale.x,scale.y);

	qlock(ctl);
	fb = ctl->getfb(ctl);
	for(sp.y = fb->r.min.y, dp.y = dst->r.min.y; sp.y < fb->r.max.y; sp.y++, dp.y += scale.y)
		for(sp.x = fb->r.min.x, dp.x = dst->r.min.x; sp.x < fb->r.max.x; sp.x++, dp.x += scale.x){
			for(i = 0; i < scale.x*scale.y; i++)
				blk[i] = fb->cb[Dx(fb->r)*sp.y + sp.x];
			loadmemimage(dst, rectaddpt(blkr, dp), (uchar*)blk, scale.x*scale.y*4);
		}
	qunlock(ctl);
	free(blk);
}

static void
framebufctl_drawnormals(Framebufctl *ctl, Image *dst)
{
	Framebuf *fb;

	qlock(ctl);
	fb = ctl->getfb(ctl);
	loadimage(dst, rectaddpt(fb->r, dst->r.min), (uchar*)fb->nb, Dx(fb->r)*Dy(fb->r)*4);
	qunlock(ctl);
}

static void
framebufctl_swap(Framebufctl *ctl)
{
	qlock(ctl);
	ctl->idx ^= 1;
	qunlock(ctl);
}

static void
framebufctl_reset(Framebufctl *ctl)
{
	Framebuf *fb;

	/* address the back buffer—resetting the front buffer is VERBOTEN */
	fb = ctl->getbb(ctl);
	memset(fb->nb, 0, Dx(fb->r)*Dy(fb->r)*4);
	memsetd(fb->zb, Inf(-1), Dx(fb->r)*Dy(fb->r));
	memset(fb->cb, 0, Dx(fb->r)*Dy(fb->r)*4);
}

static Framebuf *
framebufctl_getfb(Framebufctl *ctl)
{
	return ctl->fb[ctl->idx];	/* front buffer */
}

static Framebuf *
framebufctl_getbb(Framebufctl *ctl)
{
	return ctl->fb[ctl->idx^1];	/* back buffer */
}

Framebuf *
mkfb(Rectangle r)
{
	Framebuf *fb;

	fb = emalloc(sizeof *fb);
	memset(fb, 0, sizeof *fb);
	fb->cb = emalloc(Dx(r)*Dy(r)*4);
	fb->zb = emalloc(Dx(r)*Dy(r)*sizeof(*fb->zb));
	memsetd(fb->zb, Inf(-1), Dx(r)*Dy(r));
	fb->nb = emalloc(Dx(r)*Dy(r)*4);
	fb->r = r;
	return fb;
}

void
rmfb(Framebuf *fb)
{
	free(fb->zb);
	free(fb->cb);
	free(fb);
}

Framebufctl *
mkfbctl(Rectangle r)
{
	Framebufctl *fc;

	fc = emalloc(sizeof *fc);
	memset(fc, 0, sizeof *fc);
	fc->fb[0] = mkfb(r);
	fc->fb[1] = mkfb(r);
	fc->draw = framebufctl_draw;
	fc->upscaledraw = framebufctl_upscaledraw;
	fc->memdraw = framebufctl_memdraw;
	fc->upscalememdraw = framebufctl_upscalememdraw;
	fc->drawnormals = framebufctl_drawnormals;
	fc->swap = framebufctl_swap;
	fc->reset = framebufctl_reset;
	fc->getfb = framebufctl_getfb;
	fc->getbb = framebufctl_getbb;
	return fc;
}

void
rmfbctl(Framebufctl *fc)
{
	rmfb(fc->fb[1]);
	rmfb(fc->fb[0]);
	free(fc);
}