mousecur.c

一个利用SDL语言来实现svgalib函数的示例程序

/* zgv 5.9 - GIF, JPEG and PBM/PGM/PPM viewer, for VGA PCs running Linux.
 * Copyright (C) 1993-2005 Russell Marks. See README for license details.
 *
 * mousecur.c - mouse cursor routines.
 *
 * These all check has_mouse and return if zero, so there's no need
 * to check that before calling them.
 *
 * SDL mouse support by Dimitar Zhekov.
 */

#ifdef BACKEND_SDL

#include <stdlib.h>
#include <SDL/SDL.h>
#include "zgv.h"

static int usenarrow=0;

#define MOUSECUR_XSIZE	16
#define MOUSECUR_YSIZE	16
#define MOUSECUR_PIXMAP_SIZE	(((MOUSECUR_XSIZE+7)/8)*MOUSECUR_YSIZE)

/* data for zgv's mouse cursor, see non-SDL version */
static Uint8 mouse_data[MOUSECUR_PIXMAP_SIZE] =
  {
  0x00, 0x00, 0x60, 0x00, 0x78, 0x00, 0x3e, 0x00,
  0x3f, 0x80, 0x1f, 0xe0, 0x1f, 0xf8, 0x0f, 0x80,
  0x0f, 0x80, 0x06, 0x40, 0x06, 0x20, 0x02, 0x10,
  0x02, 0x08, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00
  };

static Uint8 mouse_mask[MOUSECUR_PIXMAP_SIZE] =
  {
  0x60, 0x00, 0xf8, 0x00, 0xfe, 0x00, 0x7f, 0x80,
  0x7f, 0xe0, 0x3f, 0xf8, 0x3f, 0xfc, 0x1f, 0xf8,
  0x1f, 0xc0, 0x0f, 0xe0, 0x0f, 0x70, 0x07, 0x38,
  0x07, 0x1c, 0x02, 0x0e, 0x00, 0x04, 0x00, 0x00
  };

static Uint8 mouse_data_narrow[MOUSECUR_PIXMAP_SIZE/2] =
  {
  0x00, 0x40, 0x60, 0x70, 0x78, 0x3c, 0x3e, 0x38,
  0x38, 0x14, 0x14, 0x12, 0x12, 0x00, 0x00, 0x00
  };

static Uint8 mouse_mask_narrow[MOUSECUR_PIXMAP_SIZE/2] =
  {
  0x40, 0xe0, 0xf0, 0xf8, 0xfc, 0x7e, 0x7f, 0x7e,
  0x7c, 0x3e, 0x3e, 0x3f, 0x3f, 0x12, 0x00, 0x00
  };

static Uint8 mouse_data_hidden[1] = { 0 }, mouse_mask_hidden[1] = { 0 };

static SDL_Cursor *mouse_cursor=NULL, *mouse_cursor_narrow, *mouse_cursor_hidden;



void mousecur_init(int blackcol,int whitecol)
{
SDL_Surface *surface=SDL_GetVideoSurface();

if(!has_mouse || !surface) return;

if(!mouse_cursor)
  {
  mouse_cursor=SDL_CreateCursor(mouse_data, mouse_mask, MOUSECUR_XSIZE,
                                MOUSECUR_YSIZE, 0, 0);
  mouse_cursor_narrow=SDL_CreateCursor(mouse_data_narrow, mouse_mask_narrow,
                                MOUSECUR_XSIZE/2, MOUSECUR_YSIZE, 0, 0);
  mouse_cursor_hidden=SDL_CreateCursor(mouse_data_hidden, mouse_mask_hidden,
                                1, 1, 0, 0);
  if(!mouse_cursor || !mouse_cursor_narrow || !mouse_cursor_hidden)
    {
    fprintf(stderr, "zgv: SDL create cursor failed - %s\n"
                    "     mouse support disabled...\n", SDL_GetError());
    has_mouse=0;
    return;
    }
  SDL_ShowCursor(SDL_ENABLE);
  }

usenarrow=((surface->w==320 && surface->h==400) ||
           (surface->w==360 && surface->h==480));
}

void mousecur_on(void)
{
if(has_mouse) SDL_SetCursor(usenarrow ? mouse_cursor_narrow : mouse_cursor);
}

void mousecur_off(void)
{
if(has_mouse) SDL_SetCursor(mouse_cursor_hidden);
}


#else	/* !BACKEND_SDL */


#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "zgv_io.h"
#include "rc_config.h"
#include "rcfile.h"
#include "zgv.h"

/* Zgv has more problems with drawing a mouse cursor than most
 * svgalib programs would. For example, since we need to support 640x480
 * 16-colour mode, we can't use any vgagl stuff, or at least not
 * exclusively. And for 320x400/360x480 modes, we have a specially
 * squished pointer. :-)
 */

static int usegl=-1,usenarrow=-1;

/* for area-under-cursor save buffer.
 * width/height may be less than sizes below if near edge of screen.
 */
static int savex,savey,savew,saveh;

static int screen_width,screen_height,screen_bytepp;

#define MOUSECUR_XSIZE	16
#define MOUSECUR_YSIZE	16
#define MOUSECUR_PIXMAP_SIZE	(MOUSECUR_XSIZE*MOUSECUR_YSIZE)

/* next two pixmaps are *4 as must be able to handle up to 32-bpp modes */
static unsigned char mouseptr_save[MOUSECUR_PIXMAP_SIZE*4];
static unsigned char mouseptr_pixmap[MOUSECUR_PIXMAP_SIZE*4];
static unsigned char mouseptr_pixmap_orig[MOUSECUR_PIXMAP_SIZE]=
  {
  /* 1 is black, 2 is white, 0 is transparent */
  0,2,2,0,0,0,0,0,0,0,0,0,0,0,0,0,
  2,1,1,2,2,0,0,0,0,0,0,0,0,0,0,0,
  2,1,1,1,1,2,2,0,0,0,0,0,0,0,0,0,
  0,2,1,1,1,1,1,2,2,0,0,0,0,0,0,0,
  0,2,1,1,1,1,1,1,1,2,2,0,0,0,0,0,
  0,0,2,1,1,1,1,1,1,1,1,2,2,0,0,0,
  0,0,2,1,1,1,1,1,1,1,1,1,1,2,0,0,
  0,0,0,2,1,1,1,1,1,2,2,2,2,0,0,0,
  0,0,0,2,1,1,1,1,1,2,0,0,0,0,0,0,
  0,0,0,0,2,1,1,2,2,1,2,0,0,0,0,0,
  0,0,0,0,2,1,1,2,0,2,1,2,0,0,0,0,
  0,0,0,0,0,2,1,2,0,0,2,1,2,0,0,0,
  0,0,0,0,0,2,1,2,0,0,0,2,1,2,0,0,
  0,0,0,0,0,0,2,0,0,0,0,0,2,1,2,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,2,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
  };

static unsigned char mouseptr_pixmap_narrow_orig[MOUSECUR_PIXMAP_SIZE/2]=
  {
  /* 1 is black, 2 is white, 0 is transparent */
  0,2,0,0,0,0,0,0,
  2,1,2,0,0,0,0,0,
  2,1,1,2,0,0,0,0,
  2,1,1,1,2,0,0,0,
  2,1,1,1,1,2,0,0,
  0,2,1,1,1,1,2,0,
  0,2,1,1,1,1,1,2,
  0,2,1,1,1,2,2,0,
  0,2,1,1,1,2,0,0,
  0,0,2,1,2,1,2,0,
  0,0,2,1,2,1,2,0,
  0,0,2,1,2,2,1,2,
  0,0,2,1,2,2,1,2,
  0,0,0,2,0,0,2,0,
  0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0
  };





void mousecur_init(int blackcol,int whitecol)
{
int f,val;
int mode=vga_getcurrentmode();

if(!has_mouse) return;

screen_bytepp=vga_getmodeinfo(mode)->bytesperpixel;

screen_width =vga_getxdim();
screen_height=vga_getydim();

mouse_setxrange(0,screen_width-1);
mouse_setyrange(0,screen_height-1);

switch(mode)
  {
  case G640x480x16:
  case G320x200x256: case G320x240x256:
  case G320x400x256: case G360x480x256:
    usegl=0; break;
  default:
    usegl=1;
  }

usenarrow=(mode==G320x400x256 || mode==G360x480x256);

if(usegl)
  gl_setcontextvga(vga_getcurrentmode());

for(f=0;f<(usenarrow?MOUSECUR_PIXMAP_SIZE/2:MOUSECUR_PIXMAP_SIZE);f++)
  {
  switch(usenarrow?mouseptr_pixmap_narrow_orig[f]:mouseptr_pixmap_orig[f])
    {
    case 1: /* black */
      val=blackcol; break;
    case 2: /* white (ish :-)) */
      val=whitecol; break;
    default: /* assume zero - transparent */
      val=0; break;
    }
  
  switch(screen_bytepp)
    {
    case 4:
      mouseptr_pixmap[f*4  ]=(val&255);
      mouseptr_pixmap[f*4+1]=(val>>8);
      mouseptr_pixmap[f*4+2]=(val>>16);
      mouseptr_pixmap[f*4+3]=0;
      break;
    case 3:
      mouseptr_pixmap[f*3  ]=(val&255);
      mouseptr_pixmap[f*3+1]=(val>>8);
      mouseptr_pixmap[f*3+2]=(val>>16);
      break;
    case 2:
      mouseptr_pixmap[f*2  ]=(val&255);
      mouseptr_pixmap[f*2+1]=(val>>8);
      break;
    default:
      mouseptr_pixmap[f]=val;
    }
  }
}


void mousecur_on()
{
int small=0,y;

if(!has_mouse) return;

savex=mouse_getx();
savey=mouse_gety();
savew=MOUSECUR_XSIZE;
saveh=MOUSECUR_YSIZE;
if(usenarrow) savew/=2;
/* deal with being near edge of screen */
if(savex>screen_width-savew)
  savew=screen_width-savex,small=1;
if(savey>screen_height-saveh)
  saveh=screen_height-savey,small=1;

/* we need to save existing data, then draw the mouse. */
if(usegl)
  {
  /* gl-using 8/15/16/24/32-bpp version */
  gl_getbox(savex,savey,savew,saveh,mouseptr_save);
  /* since there's no gl_putboxpartmask, and clipping doesn't work for
   * gl_putboxmask, we have to do either masking or clipping ourselves.
   * Hmm. I'll pick clipping, I think...
   */
  if(small)
    /* do it a line at a time */
    for(y=0;y<saveh;y++)
      gl_putboxmask(savex,savey+y,savew,1,
      			mouseptr_pixmap+MOUSECUR_XSIZE*y*screen_bytepp);
  else
    /* full size, no problem */
    gl_putboxmask(savex,savey,savew,saveh,mouseptr_pixmap);
  }
else
  {
  static unsigned char scantmp[80];
  unsigned char *saveptr,*inptr,*outptr;
  int x;
  
  /* 16-col and low-res-8-bit version */
  
  /* save area */
  saveptr=mouseptr_save;
  for(y=0;y<saveh;y++,saveptr+=savew)
    vga_getscansegment(saveptr,savex,savey+y,savew);
  
  saveptr=mouseptr_save;
  for(y=0;y<saveh;y++)
    {
    inptr=mouseptr_pixmap+y*(usenarrow?MOUSECUR_XSIZE/2:MOUSECUR_XSIZE);
    outptr=scantmp;
    for(x=0;x<savew;x++,inptr++,saveptr++)
      *outptr++=((*inptr)?(*inptr):(*saveptr));
    vga_drawscansegment(scantmp,savex,savey+y,savew);
    }
  }
}


void mousecur_off()
{
if(!has_mouse) return;

/* redraw saved data */
if(usegl)
  gl_putbox(savex,savey,savew,saveh,mouseptr_save);
else
  {
  unsigned char *saveptr=mouseptr_save;
  int y;

  for(y=0;y<saveh;y++,saveptr+=savew)
    vga_drawscansegment(saveptr,savex,savey+y,savew);
  }
}


#endif	/* !BACKEND_SDL */