png2sp1sprite.py

Quick and dirty png to sprite converter. Right now it only uses 1-bit sprites (no color), and ignores color info. Based on https://github.com/z88dk/z88dk/blob/master/doc/ZXSpectrumZSDCCnewlib_SP1_04_BiggerSprites.md And inspired in https://github.com/reidrac/png2sprite

Usage

png2sp1sprite catinv.png -i sprite_prota

Using in sp1 (using parts of the tutorial)

• HEADS UP: Tested on zcc 20170112 version
• Just generate the sprite from the PNG:

png2sp1sprite cat.png -i mothership_col > gr_window.asm

• Then Create your C game and use it!

#pragma output REGISTER_SP = 0xD000

#include <z80.h>
#include <arch/zx.h>
#include <arch/zx/sp1.h>

extern unsigned char mothership_col1[];
extern unsigned char mothership_col2[];
extern unsigned char mothership_col3[];
extern unsigned char mothership_col4[];
extern unsigned char mothership_col5[];
extern unsigned char mothership_col6[];

struct sp1_Rect full_screen = {0, 0, 32, 24};

int main()
{
  struct sp1_ss  *mothership_sprite;
  unsigned char x;

  zx_border(INK_BLACK);

  sp1_Initialize( SP1_IFLAG_MAKE_ROTTBL | SP1_IFLAG_OVERWRITE_TILES | SP1_IFLAG_OVERWRITE_DFILE,
                  INK_BLACK | PAPER_WHITE,
                  'X' );
  sp1_Invalidate(&full_screen);

  mothership_sprite = sp1_CreateSpr(SP1_DRAW_MASK2LB, SP1_TYPE_2BYTE, 3, (int)mothership_col1, 0);
  sp1_AddColSpr(mothership_sprite, SP1_DRAW_MASK2,    SP1_TYPE_2BYTE, (int)mothership_col2, 0);
  sp1_AddColSpr(mothership_sprite, SP1_DRAW_MASK2,    SP1_TYPE_2BYTE, (int)mothership_col3, 0);
  sp1_AddColSpr(mothership_sprite, SP1_DRAW_MASK2,    SP1_TYPE_2BYTE, (int)mothership_col4, 0);

  sp1_AddColSpr(mothership_sprite, SP1_DRAW_MASK2RB,  SP1_TYPE_2BYTE, 0, 0);

  x=0;
  while(1)
  {
    sp1_MoveSprPix(mothership_sprite, &full_screen, 0, x++, 0);

    z80_delay_ms(10);
    sp1_UpdateNow();
  }
}

• Modify the third parameter of sp1_CreateSpr is correlated with your sprite heigh.
• Do as many calls to sp1_AddColSpr as the script generated. See that last one is 'special'

And it works!

What about animated sprites?

Just add the next frame next to current sprite (in x), and then use -f WIDTH of each sprite frame.

e.g. an image of 64 px width will generate TWO frames: png2sp1sprite cat_animated.png -i sprite_protar -f 32

See this thread https://www.z88dk.org/forum/viewtopic.php?id=10277

Then sp1_MoveSprPix allows you to change the displayed sprite part.

e.g. if the sprite is 32x16, as it has mask, take the height=16, multiply by 2 (because of mask), and add a 16 bytes margin. 16x2 = 32 + 16=48 + DELTA = so 49 will be the second frame: sp1_MoveSprPix(mothership_sprite, &full_screen, (void*) 49, x++, 0);

And... udgs?

png2udg my8x8udgfile.png

Future work

Be able to 'cut' a big UDG file into smaller udgs.