Plot sprite

I have some 64×32 sprites, some defined in C16 (‘1’ and ‘2’) and some in C256 (‘3’ and ‘4’). If I plot them in C16 (mode 27), then the C256 sprites are plotted double width whereas if I plot them in C256 then the C16 sprites are plotted half width.

See image

>LIST
   10REM >TestPlot
   20*SLOAD TestFruit
   30PROCDisplay(28)
   40*screensave s01
   50W=GET
   60PROCDisplay(27)
   70*screensave s02
   80END
   90:
  100DEFPROCDisplay(m%)
  110MODE m%
  120m%=MODE
  130IF m%=27 THEN
  140  COLOUR 0,&EE,&EE,&EE:REM Light grey
  150  COLOUR 1,&FF,&FF,&FF:REM White
  160  COLOUR 2,&DE,&12,&12:REM Red
  170  COLOUR 3,&EC,&F0,&2D:REM Yellow as on bell & 3
  180  COLOUR 4,&00,&88,&00:REM Dark green table cells
  190  COLOUR 5,&01,&01,&CD:REM Blue as on plum
  200  COLOUR 6,&00,&CC,&CC:REM Cyan
  210  COLOUR 7,0,0,0:REM Black
  220  COLOUR 8,&DC,&9F,&86:REM Pale pink
  230  COLOUR 9,&DF,&51,&4D:REM Pale red
  240  COLOUR 10,&57,&A0,&1A:REM Mid green
  250  COLOUR 11,&92,&00,&00:REM Dark red, text on table
  260  COLOUR 12,&AA,&AA,&AA:REM Pale grey
  270  COLOUR 13,&22,&EE,&22:REM Bright green
  280  COLOUR 14,&DD,&11,&DD:REM Mauve as on grape
  290  COLOUR 15,&12,&12,&55:REM Dark blue
  300ENDIF
  310PRINT "Mode = ";MODE
  320*SCHOOSE sprite2
  330PLOT 237,100,100
  340*schoose sprite4
  350PLOT 237,228,100
  360*schoose sprite7
  370PLOT 237,356,100
  380*schoose sprite11
  390PLOT 237,484,100
  400ENDPROC
>

Is this expected behaviour please (I know the colours look odd but that is a longer story and they are actually what I am expecting)?

Yes, that’s expected behaviour. PLOT/OS_Plot uses OS_SpriteOp 28 (or 48 for mask plotting). These are “dumb” plot routines which don’t do any colour translation or pixel format conversion – they basically just copy bytes from the sprite/mask directly to the screen (while applying the GCOL action). So a 64 pixel wide 8bpp sprite will appear 64*8/4 = 128 pixels wide in a 4bpp mode, and a 64 pixel wide 4bpp sprite will appear 64*4/8 = 32 pixels wide in an 8bpp mode.

If you want to plot sprites where the palette is important, or where the colour depth/pixel format differs, you’ll have to switch to using OS_SpriteOp 52, with whatever translation table ColourTrans generates for you.

Many thanks.