/*
 * Copyright 2005, Stephan Aßmus <superstippi@gmx.de>
 * Copyright 2015, Julian Harnath <julian.harnath@rwth-aachen.de>
 * All rights reserved. Distributed under the terms of the MIT License.
 *
 * DrawingMode implementing B_OP_ALPHA in "Pixel Composite" mode on B_RGBA32.
 *
 */

#ifndef DRAWING_MODE_ALPHA_PC_SOLID_H
#define DRAWING_MODE_ALPHA_PC_SOLID_H

#include "DrawingMode.h"


#define BLEND_ALPHA_PC(d, r, g, b, a) \
{ \
        BLEND_COMPOSITE16(d, r, g, b, a); \
}


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


void
blend_pixel_alpha_pc_solid(int x, int y, const color_type& color, uint8 cover,
                                         agg_buffer* buffer, const PatternHandler*)
{
        uint8* p = buffer->row_ptr(y) + (x << 2);
        uint16 alpha = color.a * cover;
        if (alpha == 255 * 255) {
                ASSIGN_ALPHA_PC(p, color.r, color.g, color.b);
        } else {
                BLEND_ALPHA_PC(p, color.r, color.g, color.b, alpha);
        }
}


void
blend_hline_alpha_pc_solid(int x, int y, unsigned len,
                                         const color_type& color, uint8 cover,
                                         agg_buffer* buffer, const PatternHandler*)
{
        uint8* p = buffer->row_ptr(y) + (x << 2);
        uint16 alpha = color.a * cover;
        if (alpha == 0)
                return;

        if (alpha == 255 * 255) {
                do {
                        ASSIGN_ALPHA_PC(p, color.r, color.g, color.b);
                        p += 4;
                } while(--len);
                return;
        }

        do {
                BLEND_ALPHA_PC(p, color.r, color.g, color.b, alpha);
                p += 4;
        } while(--len);
}


void
blend_solid_hspan_alpha_pc_solid(int x, int y, unsigned len,
                                                   const color_type& color, const uint8* covers,
                                                   agg_buffer* buffer, const PatternHandler*)
{
        uint8* p = buffer->row_ptr(y) + (x << 2);
        do {
                uint16 alpha = color.a * *covers;
                if (alpha) {
                        if(alpha == 255 * 255) {
                                ASSIGN_ALPHA_PC(p, color.r, color.g, color.b);
                        } else {
                                BLEND_ALPHA_PC(p, color.r, color.g, color.b, alpha);
                        }
                }
                covers++;
                p += 4;
        } while(--len);
}


void
blend_solid_vspan_alpha_pc_solid(int x, int y, unsigned len,
                                                   const color_type& color, const uint8* covers,
                                                   agg_buffer* buffer, const PatternHandler*)
{
        uint8* p = buffer->row_ptr(y) + (x << 2);
        do {
                uint16 alpha = color.a * *covers;
                if (alpha) {
                        if (alpha == 255 * 255) {
                                ASSIGN_ALPHA_PC(p, color.r, color.g, color.b);
                        } else {
                                BLEND_ALPHA_PC(p, color.r, color.g, color.b, alpha);
                        }
                }
                covers++;
                p += buffer->stride();
        } while(--len);
}


void
blend_color_hspan_alpha_pc_solid(int x, int y, unsigned len,
                                                   const color_type* colors,
                                                   const uint8* covers, uint8 cover,
                                                   agg_buffer* buffer, const PatternHandler*)
{
        uint8* p = buffer->row_ptr(y) + (x << 2);
        if (covers) {
                // non-solid opacity
                do {
                        uint16 alpha = colors->a * *covers;
                        if (alpha) {
                                if (alpha == 255 * 255) {
                                        ASSIGN_ALPHA_PC(p, colors->r, colors->g, colors->b);
                                } else {
                                        BLEND_ALPHA_PC(p, colors->r, colors->g, colors->b, alpha);
                                }
                        }
                        covers++;
                        p += 4;
                        ++colors;
                } while(--len);
        } else {
                // solid full opcacity
                uint16 alpha = colors->a * cover;
                if (alpha == 255 * 255) {
                        do {
                                ASSIGN_ALPHA_PC(p, colors->r, colors->g, colors->b);
                                p += 4;
                                ++colors;
                        } while(--len);
                // solid partial opacity
                } else if (alpha) {
                        do {
                                BLEND_ALPHA_PC(p, colors->r, colors->g, colors->b, alpha);
                                p += 4;
                                ++colors;
                        } while(--len);
                }
        }
}


#endif // DRAWING_MODE_ALPHA_PC_SOLID_H