/* DOSGRAPH.C
 * Renato Ferreira Borges
 * Setembro 94
 */

#include <stdlib.h>
#include <stdio.h>
#include <dos.h>

#include <graphics.h>
#include "dg.h"

static struct {
	int x0, x1, y0, y1;
} clip;
static int maxx, maxy;
DgMode mode = dgCOPY;

static void limit( int*p, int menor, int maior )
{
	if (*p<menor) *p=menor;
	else if (*p>maior) *p=maior;
}

static void normaliza(int *x0, int *y0, int *x1, int *y1)
{
	if (*x1 < *x0)
	{
		int x = *x0;
		*x0 = *x1;
		*x1 = x;
	}
	if (*y1 < *y0)
	{
		int y = *y0;
		*y0 = *y1;
		*y1 = y;
	}
	limit(x0, 0, maxx);
	limit(x1, 0, maxx);
	limit(y0, 0, maxy);
	limit(y1, 0, maxy);
}

static void showMouse(void)
{
	union REGS regs;
	regs.x.ax = 1;
	int86(0x33, &regs, &regs);
}

static void hideMouse(void)
{
	union REGS regs;
	regs.x.ax = 2;
	int86(0x33, &regs, &regs);
}

static void mouseInit(void)
{
	union REGS regs;

	regs.x.ax = 0;
	int86(0x33, &regs, &regs);
	showMouse();
}

int far  dgOpen(void)
{
	int gdriver = DETECT, gmode, errorcode;

	initgraph(&gdriver, &gmode, "");
	errorcode = graphresult();

	if (errorcode != grOk)
	{
		printf("Erro: %s\n", grapherrormsg(errorcode));
		return 1;
	}
	maxx = getmaxx();
	maxy = getmaxy();
	clip.x0 = 0;
	clip.y0 = 0;
	clip.x1 = maxx;
	clip.y1 = maxy;
	mode = dgCOPY;
	mouseInit();
	return 0;
}

void far  dgClose(void)
{
	closegraph();
}

int far  dgWidth(void)
{
	return maxx;
}

int far  dgHeight(void)
{
	return maxy;
}

void far  dgLine(int x0, int y0, int x1, int y1)
{
	setviewport(clip.x0, clip.y0, clip.x1, clip.y1, 1);
	hideMouse();
	line(x0-clip.x0, y0-clip.y0, x1-clip.x0, y1-clip.y0);
	showMouse();
	setviewport(0, 0, maxx, maxy, 1);
}

void far  dgRectangle(int x0, int y0, int x1, int y1)
{
	setviewport(clip.x0, clip.y0, clip.x1, clip.y1, 1);
	hideMouse();
	moveto(x0-clip.x0, y0-clip.y0);
	lineto(x0-clip.x0, y1-clip.y0);
	lineto(x1-clip.x0, y1-clip.y0);
	lineto(x1-clip.x0, y0-clip.y0);
	lineto(x0-clip.x0, y0-clip.y0);
	showMouse();
	setviewport(0, 0, maxx, maxy, 1);
}

void far  dgFill( int x0, int y0, int x1, int y1)
{
	int p[8];

	normaliza(&x0, &y0, &x1, &y1);
	setviewport(clip.x0, clip.y0, clip.x1, clip.y1, 1);
	hideMouse();
	if (mode == dgXOR)
	{
		int i=0;
		for (i=y0; i<=y1; i++)
			line(x0,i,x1,i);
	}
	else
	{
		p[0] = x0 - clip.x0;
		p[1] = y0 - clip.y0;
		p[2] = x1 - clip.x0;
		p[3] = y0 - clip.y0;
		p[4] = x1 - clip.x0;
		p[5] = y1 - clip.y0;
		p[6] = x0 - clip.x0;
		p[7] = y1 - clip.y0;
		fillpoly(4, p);
	}
	showMouse();
	setviewport(0, 0, maxx, maxy, 1);
}

void far  dgSetColor(DgColor cor)
{
	setcolor((int)cor);
	setfillstyle(1, (int)cor);
}

void far  dgSetMode(DgMode modo)
{
	mode = modo;
	setwritemode((int)modo);
}

void far  dgClear(int x0, int y0, int x1, int y1)
{
	setviewport(x0, y0, x1, y1, 1);
	hideMouse();
	clearviewport();
	showMouse();
	setviewport(0, 0, maxx, maxy, 1);
}

void far  dgMove(int x0, int y0, int x1, int y1, int newx, int newy)
{
	unsigned size;
	void *image;

	normaliza(&x0, &y0, &x1, &y1);
	if (x0==newx && y0==newy) return;
	size = imagesize(x0,y0,x1,y1);
	if (size==0xffff) return;
	image = malloc(size);
	getimage(x0,y0,x1,y1,image);
	putimage(newx, newy, image, COPY_PUT);
	free(image);
}

void far  dgClip(int x0, int y0, int x1, int y1)
{
	normaliza(&x0, &y0, &x1, &y1);
	clip.x0 = x0;
	clip.x1 = x1;
	clip.y0 = y0;
	clip.y1 = y1;
}

DgEventType far  dgGetEvent(DgEvent far* ev)
{
	union REGS regs;
	static int x=0, y=0, b1=0, b2=0;

	while (1)
	{
		regs.x.ax = 3;
		int86(0x33, &regs, &regs);
		if (b1!=(regs.x.bx&1))
		{
			b1 = regs.x.bx&1;
			ev->x = x;
			ev->y = y;
			if (b1==0)
			{
				ev->tipo = dgUNCLICK1;
				return dgUNCLICK1;
			}
			else
			{
				ev->tipo = dgCLICK1;
				return dgCLICK1;
			}
		}
		if (b2!=(regs.x.bx&2))
		{
			b2 = regs.x.bx&2;
			ev->x = x;
			ev->y = y;
			if (b2==0)
			{
				ev->tipo = dgUNCLICK2;
				return dgUNCLICK2;
			}
			else
			{
				ev->tipo = dgCLICK2;
				return dgCLICK2;
			}
		}
		if ((x!=regs.x.cx) || (y!=regs.x.dx))
		{
			x = regs.x.cx;
			y = regs.x.dx;
			ev->x = x;
			ev->y = y;
			ev->tipo = dgMOVE;
			return dgMOVE;
		}
	}
}

int far points[200];
int used;

void far dgBeginPoly()
{
	used = 0;
}

void far dgPolyPoint(int x, int y)
{
	points[used++]=x;
	points[used++]=y;
}

void far dgEndPoly(DgPolyType type)
{
	hideMouse();
	switch (type)
	{
		case dgOPENED:
			drawpoly(used/2, points);
			break;
		case dgCLOSED:
			points[used++] = points[0];
			points[used++] = points[1];
			drawpoly(used/2, points);
			break;
		case dgFILL:
			fillpoly(used/2, points);
			break;
	}
	showMouse();
}