#include <vga.h>
#include <vgagl.h>
#include <vgakeyboard.h>
#include <stdio.h>

#define ERASE 0
#define DRAW  1

void kbdhandler(int, int);
void clearCar(int, int);
void drawCar(int, int);
void drawPoles(int, int);

static int cX, cY;
static int POLE_OFFSET = 0;
static double tan = (double)16/(double)19;
static int K_105 = 0, K_106 = 0, K_103 = 0;

int
main() {
	int c, y, i;
	double x;

	cX = 270;
	cY = 380;

	vga_init();
	vga_setmode(G640x480x256);
	keyboard_init();
	keyboard_seteventhandler(kbdhandler);

	gl_setcontextvga(G640x480x256);
	gl_setrgbpalette();

	gl_fillbox(0, 0, 640, 100, 15);
	for (y=10; y<380; y++) {
		x = 320.0 - (double)y * tan;
		gl_hline(0, y+90, x, 48);
		gl_hline(x, y+90, 640 - x, 255);
		gl_hline(640 - x, y+90, 640, 48);
		}
	drawCar(cX, cY);
	for (i=0; i<12; i+=2)
		drawPoles(i+1, DRAW);
	while (1)
		keyboard_update();
	vga_setmode(TEXT);
	keyboard_close();
	return (0);
}

void
drawCar(int x, int y)
{
	gl_fillbox(x + 30, y, 60, 20, 15);
	gl_fillbox(x + 20, y + 20, 80, 30, 200);

	gl_fillbox(x, y + 30, 40, 40, 0);
	gl_fillbox(x + 80, y + 30, 40, 40, 0);

	gl_fillbox(x + 25, y + 10, 5, 10, 0);
	gl_fillbox(x + 90, y + 10, 5, 10, 0);
}

void
clearCar(int x, int y)
{
	gl_fillbox(x, y, 125, 70, 255);
}

void
kbdhandler(int scan, int press)
{
	int i, j;
	switch (press) {
		case KEY_EVENTPRESS:
			switch(scan) {
				case 105:
					K_105 = 1;
				break;
				case 106:
					K_106 = 1;
				break;
				case 103:
					K_103 = 1;
				break;
			}
		break;

		case KEY_EVENTRELEASE:
			switch(scan) {
				case 105:
					K_105 = 0;
				break;
				case 106:
					K_106 = 0;
				break;
				case 103:
					K_103 = 0;
					for (j=200; j>0; j--) {
					clearCar(cX, cY);
					cY-=2;
					drawCar(cX, cY);
			
					if (POLE_OFFSET) {
						POLE_OFFSET = 0;
						for (i=0; i<12; i+=2)
							drawPoles(i+1, ERASE);
						for (i=1; i<12; i+=2)
							drawPoles(i+1, DRAW);
					} else {
						POLE_OFFSET = 1;
						for (i=1; i<12; i+=2)
							drawPoles(i+1, ERASE);
						for (i=0; i<12; i+=2)
							drawPoles(i+1, DRAW);
						}
					clearCar(cX, cY);
					cY+=2;
					drawCar(cX, cY);
					}
				break;
			}
				break;
	}

	if (K_103) {
		clearCar(cX, cY);
		cY-=2;
		drawCar(cX, cY);

		if (POLE_OFFSET) {
			POLE_OFFSET = 0;
			for (i=0; i<12; i+=2)
				drawPoles(i+1, ERASE);
			for (i=1; i<12; i+=2)
				drawPoles(i+1, DRAW);
		} else {
			POLE_OFFSET = 1;
			for (i=1; i<12; i+=2)
				drawPoles(i+1, ERASE);
			for (i=0; i<12; i+=2)
				drawPoles(i+1, DRAW);
			}
		clearCar(cX, cY);
		cY+=2;
		drawCar(cX, cY);
	}
	if (K_105) {
		if (cX >= 85) {
		clearCar(cX, cY);
		cX-=10;
		drawCar(cX, cY);
		}
	} else
	if (K_106) {
		if (cX <= 430) {
		clearCar(cX, cY);
		cX+=10;
		drawCar(cX, cY);
		}
	}
}

void
drawPoles(int y, int erase)
{
	int c;
	double x, y2;
	y = y * 30;
	x = 320.0 - y * tan;
	if (erase == DRAW)
		c = 64;
	else
		c = 48;
	y2 = 0.6 * (double)(y + 100);
	gl_line(x-20, y+100, x-20, y2, c);
	gl_line(660 - x, y+100, 660 - x, y2, c);
}