/*
 * DIB driver primitives.
 *
 * Copyright 2011 Huw Davies
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

#include "gdi_private.h"
#include "dibdrv.h"

static inline DWORD *get_pixel_ptr_32(const dib_info *dib, int x, int y)
{
    return (DWORD *)((BYTE*)dib->bits + y * dib->stride + x * 4);
}

static inline void do_rop_32(DWORD *ptr, DWORD and, DWORD xor)
{
    *ptr = (*ptr & and) ^ xor;
}

static void solid_rects_32(const dib_info *dib, int num, const RECT *rc, DWORD and, DWORD xor)
{
    DWORD *ptr, *start;
    int x, y, i;

    for(i = 0; i < num; i++, rc++)
    {
        start = ptr = get_pixel_ptr_32(dib, rc->left, rc->top);
        for(y = rc->top; y < rc->bottom; y++, start += dib->stride / 4)
            for(x = rc->left, ptr = start; x < rc->right; x++)
                do_rop_32(ptr++, and, xor);
    }
}

static void solid_rects_null(const dib_info *dib, int num, const RECT *rc, DWORD and, DWORD xor)
{
    return;
}

static inline INT calc_offset(INT edge, INT size, INT origin)
{
    INT offset;

    if(edge - origin >= 0)
        offset = (edge - origin) % size;
    else
    {
        offset = (origin - edge) % size;
        if(offset) offset = size - offset;
    }
    return offset;
}

static inline POINT calc_brush_offset(const RECT *rc, const dib_info *brush, const POINT *origin)
{
    POINT offset;

    offset.x = calc_offset(rc->left, brush->width,  origin->x);
    offset.y = calc_offset(rc->top,  brush->height, origin->y);

    return offset;
}

static void pattern_rects_32(const dib_info *dib, int num, const RECT *rc, const POINT *origin,
                             const dib_info *brush, void *and_bits, void *xor_bits)
{
    DWORD *ptr, *start, *start_and, *and_ptr, *start_xor, *xor_ptr;
    int x, y, i;
    POINT offset;

    for(i = 0; i < num; i++, rc++)
    {
        offset = calc_brush_offset(rc, brush, origin);

        start = get_pixel_ptr_32(dib, rc->left, rc->top);
        start_and = (DWORD*)and_bits + offset.y * brush->stride / 4;
        start_xor = (DWORD*)xor_bits + offset.y * brush->stride / 4;

        for(y = rc->top; y < rc->bottom; y++, start += dib->stride / 4)
        {
            and_ptr = start_and + offset.x;
            xor_ptr = start_xor + offset.x;

            for(x = rc->left, ptr = start; x < rc->right; x++)
            {
                do_rop_32(ptr++, *and_ptr++, *xor_ptr++);
                if(and_ptr == start_and + brush->width)
                {
                    and_ptr = start_and;
                    xor_ptr = start_xor;
                }
            }

            offset.y++;
            if(offset.y == brush->height)
            {
                start_and = and_bits;
                start_xor = xor_bits;
                offset.y = 0;
            }
            else
            {
                start_and += brush->stride / 4;
                start_xor += brush->stride / 4;
            }
        }
    }
}

static void pattern_rects_null(const dib_info *dib, int num, const RECT *rc, const POINT *origin,
                               const dib_info *brush, void *and_bits, void *xor_bits)
{
    return;
}

static DWORD colorref_to_pixel_888(const dib_info *dib, COLORREF color)
{
    return ( ((color >> 16) & 0xff) | (color & 0xff00) | ((color << 16) & 0xff0000) );
}

static inline DWORD put_field(DWORD field, int shift, int len)
{
    shift = shift - (8 - len);
    if (len <= 8)
        field &= (((1 << len) - 1) << (8 - len));
    if (shift < 0)
        field >>= -shift;
    else
        field <<= shift;
    return field;
}

static DWORD colorref_to_pixel_masks(const dib_info *dib, COLORREF colour)
{
    DWORD r,g,b;

    r = GetRValue(colour);
    g = GetGValue(colour);
    b = GetBValue(colour);

    return put_field(r, dib->red_shift,   dib->red_len) |
           put_field(g, dib->green_shift, dib->green_len) |
           put_field(b, dib->blue_shift,  dib->blue_len);
}

static DWORD colorref_to_pixel_null(const dib_info *dib, COLORREF color)
{
    return 0;
}

const primitive_funcs funcs_8888 =
{
    solid_rects_32,
    pattern_rects_32,
    colorref_to_pixel_888
};

const primitive_funcs funcs_32 =
{
    solid_rects_32,
    pattern_rects_32,
    colorref_to_pixel_masks
};

const primitive_funcs funcs_null =
{
    solid_rects_null,
    pattern_rects_null,
    colorref_to_pixel_null
};