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cc65/libsrc/c64/pencalib.c
Greg King 17333e4732 Fixed some line endings.
My Git and repositories are configured for POSIX; but sometimes, Windows line endings "sneak" into new files.
2013-07-25 13:53:15 -04:00

95 lines
2.6 KiB
C

/*
** Calibrate lightpen drivers to the current video hardware.
**
** 2013-07-25, Greg King
**
*/
#include <conio.h>
#include <mouse.h>
#include <pen.h>
#define COMMAND1 "Adjust by clicking on line."
#define COMMAND2 "Finish by clicking off bar."
/*
** There is a delay between when the VIC sends its signal, and when the display
** shows that signal. There is another delay between the display and when
** the lightpen says that it saw that signal. Each display and pen is different.
** Therefore, the driver must be calibrated to them. A white bar is painted on
** the screen; and, a line is drawn down the middle of it. When the user clicks
** on that line, the difference between its position and where the VIC thinks
** that the pen is pointing becomes an offset that is subtracted from what the
** VIC sees.
*/
void __fastcall__ pen_calibrate (unsigned char *XOffset)
{
unsigned char oldBg = bgcolor (COLOR_BLUE);
unsigned char oldText = textcolor (COLOR_GRAY3);
unsigned char oldRev = revers (1);
unsigned char sprite0Color = VIC.spr_color[0];
unsigned char width, width2, height, height4, height8;
struct mouse_info info;
screensize (&width, &height);
width2 = width / 2;
height4 = height / 4;
height8 = height4 * 8;
/* Draw a bar and line. */
clrscr ();
cclearxy (0, height4, height4 * width);
cvlinexy (width2, height4 + 1, height4 - 2);
revers (0);
/* Print instructions. */
cputsxy (width2 - (sizeof COMMAND1) / 2, height / 2 + 1, COMMAND1);
cputsxy (width2 - (sizeof COMMAND2) / 2, height / 2 + 3, COMMAND2);
VIC.spr_color[0] = COLOR_GRAY2;
mouse_show ();
mouse_move (width2 * 8, height8 / 2);
for (;;) {
/* Wait for the main button to be released. */
do ; while ((mouse_buttons () & MOUSE_BTN_LEFT));
/* Wait for the main button to be pressed. */
do {
mouse_info (&info);
} while (!(info.buttons & MOUSE_BTN_LEFT));
/* Find out if the pen is on or off the bar. */
if (info.pos.y < height8 || info.pos.y >= height8 * 2) {
break;
}
/* On the bar; adjust the offset. */
/* Characters are eight pixels wide.
** The VIC-II sees every other pixel;
** so, we use half of the difference.
*/
*XOffset += (info.pos.x - (width2 * 8 + 8/2)) / 2;
}
/* Off the bar; wait for the main button to be released. */
do ; while ((mouse_buttons () & MOUSE_BTN_LEFT));
mouse_hide ();
VIC.spr_color[0] = sprite0Color;
revers (oldRev);
textcolor (oldText);
bgcolor (oldBg);
clrscr ();
}