Re: [AD] scanline extension

[Bertrand Coconnier <bcoconni@xxxxxxxxxx>]

tom st denis wrote :
> 
> ok I gave it more thought... lets use this...
> 
> typedef struct {
>    BITMAP *dest,    /* destination bitmap */
>           *txt;     /* texture map if any */
>    int    x1, x2,   /* x start and end coords */
>           y,        /* line to draw on */
>           u1, u2,   /* texture x start/end */
>           v1, v2,   /* texture y start/end */
>           c1, c2;   /* color start/end */
>    float  z1,z2;    /* scanline start/end Z */
> } scanlineinfo;
> 
> void draw_scanline(scanlineinfo *sli);
> 
> Then you tell allegro
> 
> add_scanline_drawer(&draw_scanline, MYTYPE)
> 
> Where MYTYPE is an integer.

You are reinventing the wheel :-) If you take a look at iscan.s (ASM
rendering func) or cscan.h (C rendering func) you'll see that :

1. The struct you are talking about already exists : it is called
POLYGON_SEGMENT (declared in private headers file
include/allegro/aintern.h)
2. The actual rendering functions are declared this way :

void _poly_scanline_the_mode(unsigned long addr, int w, POLYGON_SEGMENT
*info)

where - addr is the BITMAP address where the scanline will be rendered
      - w is the scanline width
      - info is the structure which contains (u, du, v, dv, c, dc,
texture address, etc...)

	Bertrand.