#include "dmlib.h"


void dmFillRect(SDL_Surface *screen, int x0, int y0, int x1, int y1, Uint32 col)
{
    SDL_Rect rc;
    rc.x = x0;
    rc.y = y0;
    rc.w = x1 - x0 + 1;
    rc.h = y1 - y0 + 1;
    SDL_FillRect(screen, &rc, col);
}

#define DM_SWAP(T, A, B) { if ((B) < (A)) { T swtmp = (B); B = (A); A = swtmp; } }

void dmDrawHLine(SDL_Surface *screen, int x0, int x1, int yc, const Uint32 col)
{
    int x;
    const int bpp = screen->format->BytesPerPixel,
              cx0 = screen->clip_rect.x, cy0 = screen->clip_rect.y,
              cx1 = screen->clip_rect.x + screen->clip_rect.w - 1,
              cy1 = screen->clip_rect.y + screen->clip_rect.h - 1;
    
    DM_SWAP(int, x0, x1);
    if (yc < cy0|| yc > cy1 || x1 < cx0 || x0 > cx1) return;
    if (x0 < cx0) x0 = cx0;
    if (x1 > cx1) x1 = cx1;
    
    Uint8 *pix = screen->pixels + yc * screen->pitch + (x0 * bpp);
    switch (screen->format->BitsPerPixel)
    {
        case 8:
            for (x = x0; x <= x1; x++)
                *pix++ = col;
            break;
        
        case 15:
        case 16:
            {
            Uint16 *p = (Uint16 *) pix;
            for (x = x0; x <= x1; x++)
                *p++ = col;
            }
            break;

        case 24:
            for (x = x0; x <= x1; x++)
            {
                *pix++ = col;
                *pix++ = col;
                *pix++ = col;
            }
            break;
        
        case 32:
            {
            Uint32 *p = (Uint32 *) pix;
            for (x = x0; x <= x1; x++)
                *p++ = col;
            }
            break;
    }
}


void dmDrawVLine(SDL_Surface *screen, int y0, int y1, int xc, const Uint32 col)
{
    int y;
    const int bpp = screen->format->BytesPerPixel,
              pitch = screen->pitch / bpp,
              cx0 = screen->clip_rect.x, cy0 = screen->clip_rect.y,
              cx1 = screen->clip_rect.x + screen->clip_rect.w - 1,
              cy1 = screen->clip_rect.y + screen->clip_rect.h - 1;

    DM_SWAP(int, y0, y1);
    if (xc < cx0 || xc > cx1 || y1 < cy0 || y0 > cy1) return;
    if (y0 < cy0) y0 = cy0;
    if (y1 > cy1) y1 = cy1;

    Uint8 *pix = screen->pixels + y0 * screen->pitch + (xc * bpp);
    switch (screen->format->BitsPerPixel)
    {
        case 8:
            for (y = y0; y <= y1; y++, pix += pitch)
                *pix = col;
            break;
        
        case 16:
        case 15:
            {
            Uint16 *p = (Uint16 *) pix;
            for (y = y0; y <= y1; y++, p += pitch)
                *p = col;
            }
            break;

        case 24:
            for (y = y0; y <= y1; y++, pix += pitch)
                pix[0] = pix[1] = pix[2] = col;
            break;
        
        case 32:
            {
            Uint32 *p = (Uint32 *) pix;
            for (y = y0; y <= y1; y++, p += pitch)
                *p = col;
            }
            break;
    }
}


void dmDrawBox3D(SDL_Surface *screen, int x0, int y0, int x1, int y1, Uint32 bgcol, Uint32 ucol, Uint32 dcol)
{
    SDL_Rect rc;

    rc.x = x0 + 1;
    rc.y = y0 + 1;
    rc.w = x1 - x0 - 1;
    rc.h = y1 - y0 - 1;
    SDL_FillRect(screen, &rc, bgcol);

    dmDrawHLine(screen, x0    , x1 - 1, y0, ucol);
    dmDrawHLine(screen, x0 + 1, x1    , y1, dcol);

    dmDrawVLine(screen, y0    , y1 - 1, x0, ucol);
    dmDrawVLine(screen, y0 + 1, y1    , x1, dcol);
}


void dmClearSurface(SDL_Surface *screen, const Uint32 col)
{
    SDL_FillRect(screen, NULL, col);
}


Uint32 dmMapRGB(SDL_Surface *screen, int r, int g, int b)
{
    return SDL_MapRGB(screen->format, r, g, b);
}


Uint32 dmMapRGBA(SDL_Surface *screen, int r, int g, int b, int a)
{
    return SDL_MapRGBA(screen->format, r, g, b, a);
}


int dmDirectBlitSurface(SDL_Surface *bmp, SDL_Surface *screen)
{
    return SDL_BlitSurface(bmp, NULL, screen, NULL);
}