bounce.d

#!/usr/bin/env -S sh -c 'dmd -run "$0" "$1" "$2" "$3" | ffmpeg -f rawvideo -pixel_format rgb24 -video_size $1x$2 -i pipe: -preset ultrafast $(basename "$0" .d).mp4'
import std;
enum pixels=32;
ubyte[3*pixels] pixels_;

int sentpixels;
pragma(inline):
//void pix(T,S,U)(T r,S b,U g){
void pix(int r,int g,int b){
	sentpixels++;
	static int i=0;
	pixels_[i*3+0]=cast(ubyte)r;
	pixels_[i*3+1]=cast(ubyte)g;
	pixels_[i*3+2]=cast(ubyte)b;
	i++;
	if(i==pixels){
		stdout.rawWrite(pixels_);
		i=0;
	}
}
void pix(ubyte[] a){
	//pix(a[0]); //works when pix(int)
	//pix(a[0],a[0],a[0]);//doesnt work
	pix(a[0],a[1],a[2]);//doesnt work
	//pix!(ubyte,ubyte,ubyte)(a[0],a[1],a[2]);//doesnt work
	//pix!(int,int,int)(a[0],a[1],a[2]); //works
}
void pix(int a){
	pix(a,a,a);
}

void main(string[] s){
	int width=s[1].to!int;
	int h=s[2].to!int;
	int frames=s[3].to!int;
	int w=executeShell("convert lain.jpg -format \"%w\" info:").output.to!int;
	ubyte[] data=cast(ubyte[])executeShell("convert lain.jpg rgb:-").output;
	int x=0;
	int y=0;
	int xv=1;
	int yv=1;
	int imageh=cast(int)data.length/(w*3);
	//assert(imageh==648);
	//imageh--;
	foreach(i;0..frames){
		sentpixels=0;
		auto datai=0;
		foreach(y_;0..y){
			sentpixels=0;
			foreach(zzz;0..width){
				pix(0,0,0);
			}
			assert(sentpixels==width);
		}
		//assert(sentpixels==y*width,sentpixels.to!string~":"~(y*width).to!string);
		foreach(y_;0..imageh){
			sentpixels=0;
			foreach(x_;0..x){
				pix(0,0,0);
			}
			foreach(x_;0..w){
				//pix(datai);
				pix(data[datai*3..(datai+1)*3]);
				//pix(datai,datai,datai);
				datai++;
			}
			foreach(x_;0..width-x-w){
				pix(0,0,0);
			}
			assert(sentpixels==width);
		}
		foreach(y_;0..h-imageh-y){
			foreach(zzz;0..width){
				pix(0,0,0);
			}
		}
		//assert(sentpixels==width*h,sentpixels.to!string);
		x+=xv;
		y+=yv;
		if(x==0){xv*=-1;}
		if(y==0){yv*=-1;}
		if(x==width-w){xv*=-1;}
		if(y==h-imageh){yv*=-1;}
		
		if(x==0&&y==0){return;}
	}
}