/*
 * DMLib
 * -- Arbitrary line drawing functions
 * Programmed and designed by Matti 'ccr' Hamalainen
 * (C) Copyright 2011 Tecnic Software productions (TNSP)
 */
#include "dmlib.h"


/* Clip line coordinates. Return value:
 * = 0  : No clipping needed.
 * > 0  : Clipped. Line partially inside the clipping area.
 * < 0  : Line completely outside the clipping area.
 */
int dmClipLineCoords(int *x0, int *y0, int *x1, int *y1, SDL_Surface *screen)
{
#if 0
    const int clipX0 = screen->clip_rect.x,
              clipY0 = screen->clip_rect.y;
    const int clipX1 = clipX0 + screen->clip_rect.w - 1,
              clipY1 = clipY0 + screen->clip_rect.h - 1;
    const int dx = *x1 - *x0,
              dy = *y1 - *y0;
    DMFixedPoint k, kdx, kdy;

    // Is line completely outside the clipping area?
    if ((*x0 < clipX0 && *x1 < clipX0) || (*x0 > clipX1 && *x1 > clipX1) ||
        (*y0 < clipY0 && *y1 < clipY0) || (*y0 > clipY1 && *y1 > clipY1))
        return -1;
    
    FP_SETHL(kdx, dx);
    FP_SETHL(kdy, dy);
#endif        
    
    return 0;
}


int dmTestLineCoords(int x0, int y0, int x1, int y1, SDL_Surface *screen)
{
    return dmClipLineCoords(&x0, &y0, &x1, &y1, screen);
}


#include "dmlinefunc.h"

static const DMDrawLineFunc dmDrawLineTable[DMD_NMODES][DMD_NBITDEPTHS] =
{
    /* DMD_NONE          */ { dmDrawLine8              , dmDrawLine32 },
#if 0
    /* DMD_TRANSPARENT   */ { dmDrawLine8Transparent   , dmDrawLine32Transparent },
    /* DMD_SATURATE      */ { dmDrawLine8Saturate      , dmDrawLine32Saturate },

    /* DMD_NONE + AA     */ { NULL, NULL },
    /* DMD_TRANSP + AA   */ { NULL, NULL },
    /* DMD_SATURATE + AA */ { dmDrawLine8AASaturate    , dmDrawLine32AASaturate },
#endif
};

static const int ndmDrawLineTable = sizeof(dmDrawLineTable) / sizeof(dmDrawLineTable[0]);


DMDrawLineFunc dmGetDrawLineFunc(SDL_PixelFormat *dst, int mode)
{
    int index;
    if (dst == NULL || mode < 0 || mode >= ndmDrawLineTable)
        return NULL;

    if ((index = dmBitsPerPixel2Index(dst->BitsPerPixel)) < 0)
        return NULL;
    
    return dmDrawLineTable[mode][index];
}


int dmDrawLineAny(SDL_Surface *screen, int x0, int y0, int x1, int y1, const Uint32 col, int mode)
{
    DMDrawLineFunc bfunc = dmGetDrawLineFunc(screen->format, mode);

    if (bfunc == NULL)
        return -15;

    return bfunc(screen, x0, y0, x1, y1, col);
}