/************************************************************************** * Etch A Sketch 1.1. Computer control of the drawing toy. * * Copyright (C) 2004 Neil Fraser * * http://neil.fraser.name/hardware/etch/ * * * * This program is free software; you can redistribute it and/or * * modify it under the terms of the GNU General Public License * * as published by the Free Software Foundation. * * * * This program is distributed in the hope that it will be useful, * * but WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * * GNU General Public License (www.gnu.org) for more details. * * * * Thanks to David Brackeen for mouse code. * * http://www.brackeen.com/home/vga/mouse.html * * * * Thanks to Peter Anderson for graphics code. * * http://www.phanderson.com/graphics/ * * * * Compile with: tcc etch.c graphics.lib * * Executed with: etch [d] (where d is the delay factor) * **************************************************************************/ #include #include #include #include #define ETCH_WIDTH 1000 /* width in steps of etch a sketch */ #define ETCH_HEIGHT 700 /* height in steps of etch a sketch */ #define VIEW_WIDTH 390 /* width in pixels of view portal */ #define VIEW_HEIGHT 198 /* height in pixels of view portal */ #define SCREEN_WIDTH 640 /* width in pixels of screen */ #define SCREEN_HEIGHT 200 /* height in pixels of screen */ #define THRESHOLD 1 /* How many mouse ticks needed for one stepper step */ #define LAG 2 /* How many steps needed to compensate for the lag */ #define MOUSE_INT 0x33 #define MOUSE_RESET 0x00 #define MOUSE_GETPRESS 0x05 #define MOUSE_GETRELEASE 0x06 #define MOUSE_GETMOTION 0x0B #define LEFT_BUTTON 0x00 #define RIGHT_BUTTON 0x01 #define MIDDLE_BUTTON 0x02 #define PORT 0x3BC /* choose from: 0x3BC | 0x378 | 0x278 */ typedef unsigned char byte; typedef unsigned short word; typedef unsigned long dword; typedef short sword; /* signed word */ /************************************************************************** * get_mouse_motion * * Returns the distance the mouse has moved since it was lasted * * checked. * **************************************************************************/ void get_mouse_motion(sword *dx, sword *dy) { union REGS regs; regs.x.ax = MOUSE_GETMOTION; int86(MOUSE_INT, ®s, ®s); *dx=regs.x.cx; *dy=regs.x.dx; } /************************************************************************** * init_mouse * * Resets the mouse. Returns 0 if mouse not found. * **************************************************************************/ sword init_mouse() { sword dx,dy; union REGS regs; regs.x.ax = MOUSE_RESET; int86(MOUSE_INT, ®s, ®s); get_mouse_motion(&dx,&dy); return regs.x.ax; } /************************************************************************** * get_mouse_press * * Returns 1 if a button has been pressed since it was last checked. * **************************************************************************/ sword get_mouse_press(sword button) { union REGS regs; regs.x.ax = MOUSE_GETPRESS; regs.x.bx = button; int86(MOUSE_INT, ®s, ®s); return regs.x.bx; } /************************************************************************** * get_mouse_release * * Returns 1 if a button has been released since it was last checked. * **************************************************************************/ sword get_mouse_release(sword button) { union REGS regs; regs.x.ax = MOUSE_GETRELEASE; regs.x.bx = button; int86(MOUSE_INT, ®s, ®s); return regs.x.bx; } /************************************************************************** * clearscreen * * Clear the screen and redraw the border * **************************************************************************/ void clearscreen() { cleardevice(); setcolor(WHITE); rectangle((SCREEN_WIDTH-VIEW_WIDTH)/2-1, 0, (SCREEN_WIDTH-VIEW_WIDTH)/2+VIEW_WIDTH, VIEW_HEIGHT+1); } /************************************************************************** * Main * **************************************************************************/ int main(int argc, char *argv[]) { sword dx = 0, dy = 0; sword olddx = 0, olddy = 0; int bufferx = 0, buffery = 0; word press, release; long etchx = ETCH_WIDTH/2, etchy = ETCH_HEIGHT/2; int lagx = 0, lagy = 0; int graphdriver = DETECT; /* Expected mode will be 640x200 CGA */ int graphmode; int statusbyte; /* Latest byte received from the parallel port */ int commandbyte; /* Byte to be sent out the parallel port */ int keypress = 0; /* Latest character from keyboard */ int flipmode = 0; /* Are we tilting down (-1) up (1) or not moving (0) */ int horizontalquad = 0; /* Current step position for motor (0-3) */ int verticalquad = 0; /* Current step position for motor (0-3) */ int now; int lasttilttime = 0; int lasthorizontaltime = 0; int lastverticaltime = 0; int beep = 0; int delay = 0; int d = 0; if (argc == 2) { delay = atoi(argv[1]); printf("Delay = %d.\n", delay); } /* Initialize the mouse */ if (!init_mouse()) { printf("Mouse not found.\n"); exit(1); } /* Initialize graphics system */ initgraph(&graphdriver, &graphmode, ""); clearscreen(); while (keypress != 27) { /* start main loop */ now = time(); /* Read the keyboard and mouse buttons */ if (kbhit() != 0) keypress = getch(); else keypress = 0; if (get_mouse_press(LEFT_BUTTON) || keypress == '+') { flipmode = (flipmode == 0) ? 1 : 0; lasttilttime = now; } if (get_mouse_press(RIGHT_BUTTON) || keypress == '-') { flipmode = (flipmode == 0) ? -1 : 0; lasttilttime = now; } if (get_mouse_release(LEFT_BUTTON)) { flipmode = 0; lasttilttime = now; } if (get_mouse_release(RIGHT_BUTTON)) { flipmode = 0; lasttilttime = now; } if (keypress == ' ') { clearscreen(); } commandbyte = 0; if (flipmode != 0) { if (now > lasttilttime + 5) { flipmode = 0; /* Motor stalled? */ beep = 1; } statusbyte = inportb (PORT+1); if ((flipmode == 1) && !(statusbyte & 16) && (statusbyte & 32)) { flipmode = 0; /* Upper limit */ } if ((flipmode == -1) && (statusbyte & 16) && (statusbyte & 32)) { flipmode = 0; /* Lower limit */ clearscreen(); /* Clear CRT */ } } if (flipmode == 1) { commandbyte += 128; } else if (flipmode == -1) { commandbyte += 64; } /* printf("X = %d \t Y = %d\n", mouse.x, mouse.y); */ get_mouse_motion(&dx,&dy); /* Add a tiny bit of momentum */ dx = (dx + olddx) / 2; dy = (dy + olddy) / 2; /* Draw a velocity vector setcolor(BLACK); moveto(100,100); lineto(100+olddx,100+olddy); setcolor(WHITE); moveto(100,100); lineto(100+dx,100+dy); */ olddx = dx; olddy = dy; bufferx += dx; buffery += dy; if (bufferx>THRESHOLD) { horizontalquad++; lasthorizontaltime = now; if (lagx == LAG) { etchx++; if (etchx>ETCH_WIDTH-1) etchx=ETCH_WIDTH-1; bufferx =- THRESHOLD; } else { lagx++; } } else if (bufferx<-THRESHOLD) { horizontalquad--; lasthorizontaltime = now; if (lagx == -LAG) { etchx--; if (etchx<0) etchx=0; bufferx =+ THRESHOLD; } else { lagx--; } } if (buffery>THRESHOLD) { verticalquad++; lastverticaltime = now; if (lagy == LAG) { etchy++; if (etchy>ETCH_HEIGHT-1) etchy=ETCH_HEIGHT-1; buffery =- THRESHOLD; } else { lagy++; } } else if (buffery<-THRESHOLD) { verticalquad--; lastverticaltime = now; if (lagy == -LAG) { etchy--; if (etchy<0) etchy=0; buffery =+ THRESHOLD; } else { lagy--; } } putpixel((SCREEN_WIDTH-VIEW_WIDTH)/2 + VIEW_WIDTH*etchx/ETCH_WIDTH, 1 + VIEW_HEIGHT*etchy/ETCH_HEIGHT, WHITE); if (now > lasthorizontaltime + 1) { /* It's been over a second without movement, idle the motor */ commandbyte += (0+0+4); } else { switch (horizontalquad) { case 4: horizontalquad = 0; /* Fall through */ case 0: commandbyte += 0+0+0; break; case 1: commandbyte += 0+2+0; break; case 2: commandbyte += 1+2+0; break; case -1: horizontalquad = 3; /* Fall through */ case 3: commandbyte += 1+0+0; } } if (now > lastverticaltime + 1) { /* It's been over a second without movement, idle the motor */ commandbyte += (0+0+32); } else { switch (verticalquad) { case 4: verticalquad = 0; /* Fall through */ case 0: commandbyte += 0+0+0; break; case 1: commandbyte += 8+0+0; break; case 2: commandbyte += 8+16+0; break; case -1: verticalquad=3; /* Fall through */ case 3: commandbyte += 0+16+0; } } outportb (PORT, commandbyte); if (beep) { sound(750); /* Stall warning */ sleep(1); nosound(); beep = 0; } for (d=0; d