/*
 * Copyright 2005, Stephan Aßmus <superstippi@gmx.de>. All rights reserved.
 * Distributed under the terms of the MIT License.
 *
 * DrawingMode implementing B_OP_OVER on B_RGBA32.
 *
 */

#ifndef DRAWING_MODE_OVER_H
#define DRAWING_MODE_OVER_H

#include "DrawingMode.h"

// BLEND_OVER
#define BLEND_OVER(d, r, g, b, a) \
{ \
        BLEND(d, r, g, b, a) \
}

// ASSIGN_OVER
#define ASSIGN_OVER(d, r, g, b) \
{ \
        d[0] = (b); \
        d[1] = (g); \
        d[2] = (r); \
        d[3] = 255; \
}

// blend_pixel_over
void
blend_pixel_over(int x, int y, const color_type& c, uint8 cover,
                                 agg_buffer* buffer, const PatternHandler* pattern)
{
        if (pattern->IsHighColor(x, y)) {
                uint8* p = buffer->row_ptr(y) + (x << 2);
                rgb_color color = pattern->HighColor();
                if (cover == 255) {
                        ASSIGN_OVER(p, color.red, color.green, color.blue);
                } else {
                        BLEND_OVER(p, color.red, color.green, color.blue, cover);
                }
        }
}

// blend_hline_over
void
blend_hline_over(int x, int y, unsigned len, 
                                 const color_type& c, uint8 cover,
                                 agg_buffer* buffer, const PatternHandler* pattern)
{
        if (cover == 255) {
                rgb_color color = pattern->HighColor();
                uint32 v;
                uint8* p8 = (uint8*)&v;
                p8[0] = (uint8)color.blue;
                p8[1] = (uint8)color.green;
                p8[2] = (uint8)color.red;
                p8[3] = 255;
                uint32* p32 = (uint32*)(buffer->row_ptr(y)) + x;
                do {
                        if (pattern->IsHighColor(x, y))
                                *p32 = v;
                        p32++;
                        x++;
                } while(--len);
        } else {
                uint8* p = buffer->row_ptr(y) + (x << 2);
                rgb_color color = pattern->HighColor();
                do {
                        if (pattern->IsHighColor(x, y)) {
                                BLEND_OVER(p, color.red, color.green, color.blue, cover);
                        }
                        x++;
                        p += 4;
                } while(--len);
        }
}

// blend_solid_hspan_over
void
blend_solid_hspan_over(int x, int y, unsigned len, 
                                           const color_type& c, const uint8* covers,
                                           agg_buffer* buffer, const PatternHandler* pattern)
{
        uint8* p = buffer->row_ptr(y) + (x << 2);
        rgb_color color = pattern->HighColor();
        do {
                if (pattern->IsHighColor(x, y)) {
                        if (*covers) {
                                if (*covers == 255) {
                                        ASSIGN_OVER(p, color.red, color.green, color.blue);
                                } else {
                                        BLEND_OVER(p, color.red, color.green, color.blue, *covers);
                                }
                        }
                }
                covers++;
                p += 4;
                x++;
        } while(--len);
}



// blend_solid_vspan_over
void
blend_solid_vspan_over(int x, int y, unsigned len, 
                                           const color_type& c, const uint8* covers,
                                           agg_buffer* buffer, const PatternHandler* pattern)
{
        uint8* p = buffer->row_ptr(y) + (x << 2);
        rgb_color color = pattern->HighColor();
        do {
                if (pattern->IsHighColor(x, y)) {
                        if (*covers) {
                                if (*covers == 255) {
                                        ASSIGN_OVER(p, color.red, color.green, color.blue);
                                } else {
                                        BLEND_OVER(p, color.red, color.green, color.blue, *covers);
                                }
                        }
                }
                covers++;
                p += buffer->stride();
                y++;
        } while(--len);
}


// blend_color_hspan_over
void
blend_color_hspan_over(int x, int y, unsigned len, 
                                           const color_type* colors, 
                                           const uint8* covers, uint8 cover,
                                           agg_buffer* buffer, const PatternHandler* pattern)
{
        uint8* p = buffer->row_ptr(y) + (x << 2);
        if (covers) {
                // non-solid opacity
                do {
                        if (*covers && colors->a > 0) {
                                if (*covers == 255) {
                                        ASSIGN_OVER(p, colors->r, colors->g, colors->b);
                                } else {
                                        BLEND_OVER(p, colors->r, colors->g, colors->b, *covers);
                                }
                        }
                        covers++;
                        p += 4;
                        ++colors;
                } while(--len);
        } else {
                // solid full opcacity
                if (cover == 255) {
                        do {
                                if (colors->a > 0) {
                                        ASSIGN_OVER(p, colors->r, colors->g, colors->b);
                                }
                                p += 4;
                                ++colors;
                        } while(--len);
                // solid partial opacity
                } else if (cover) {
                        do {
                                if (colors->a > 0) {
                                        BLEND_OVER(p, colors->r, colors->g, colors->b, cover);
                                }
                                p += 4;
                                ++colors;
                        } while(--len);
                }
        }
}

#endif // DRAWING_MODE_OVER_H