/*
 * Copyright 2008, Stephan Aßmus <superstippi@gmx.de>
 * Copyright 2008, Philippe Saint-Pierre <stpere@gmail.com>
 * Copyright 2004-2009, Axel Dörfler, axeld@pinc-software.de.
 * Copyright 2024, Haiku, Inc. All rights reserved.
 * Distributed under the terms of the MIT License.
 */
#ifndef GENERIC_BLITTER_H
#define GENERIC_BLITTER_H


#include <SupportDefs.h>


struct BlitParameters {
        const uint8* from;
        uint32 fromWidth;
        uint16 fromLeft, fromTop;
        uint16 fromRight, fromBottom;

        uint8* to;
        uint32 toBytesPerRow;
        uint16 toLeft, toTop;
};


static void
blit8(const BlitParameters& params)
{
        const uint8* data = params.from;
        data += (params.fromWidth * params.fromTop + params.fromLeft);
        uint8* start = (uint8*)(params.to
                + params.toBytesPerRow * params.toTop
                + 1 * params.toLeft);

        for (int32 y = params.fromTop; y < params.fromBottom; y++) {
                const uint8* src = data;
                uint8* dst = start;
                for (int32 x = params.fromLeft; x < params.fromRight; x++) {
                        dst[0] = src[0];
                        dst++;
                        src++;
                }

                data += params.fromWidth;
                start = (uint8*)((addr_t)start + params.toBytesPerRow);
        }
}


static void
blit15(const BlitParameters& params)
{
        const uint8* data = params.from;
        data += (params.fromWidth * params.fromTop + params.fromLeft) * 3;
        uint16* start = (uint16*)(params.to
                + params.toBytesPerRow * params.toTop
                + 2 * params.toLeft);

        for (int32 y = params.fromTop; y < params.fromBottom; y++) {
                const uint8* src = data;
                uint16* dst = start;
                for (int32 x = params.fromLeft; x < params.fromRight; x++) {
                        dst[0] = ((src[2] >> 3) << 10)
                                | ((src[1] >> 3) << 5)
                                | ((src[0] >> 3));

                        dst++;
                        src += 3;
                }

                data += params.fromWidth * 3;
                start = (uint16*)((addr_t)start + params.toBytesPerRow);
        }
}


static void
blit16(const BlitParameters& params)
{
        const uint8* data = params.from;
        data += (params.fromWidth * params.fromTop + params.fromLeft) * 3;
        uint16* start = (uint16*)(params.to
                + params.toBytesPerRow * params.toTop
                + 2 * params.toLeft);

        for (int32 y = params.fromTop; y < params.fromBottom; y++) {
                const uint8* src = data;
                uint16* dst = start;
                for (int32 x = params.fromLeft; x < params.fromRight; x++) {
                        dst[0] = ((src[2] >> 3) << 11)
                                | ((src[1] >> 2) << 5)
                                | ((src[0] >> 3));

                        dst++;
                        src += 3;
                }

                data += params.fromWidth * 3;
                start = (uint16*)((addr_t)start + params.toBytesPerRow);
        }
}


static void
blit24(const BlitParameters& params)
{
        const uint8* data = params.from;
        data += (params.fromWidth * params.fromTop + params.fromLeft) * 3;
        uint8* start = (uint8*)(params.to
                + params.toBytesPerRow * params.toTop
                + 3 * params.toLeft);

        for (int32 y = params.fromTop; y < params.fromBottom; y++) {
                const uint8* src = data;
                uint8* dst = start;
                for (int32 x = params.fromLeft; x < params.fromRight; x++) {
                        dst[0] = src[0];
                        dst[1] = src[1];
                        dst[2] = src[2];
                        dst += 3;
                        src += 3;
                }

                data += params.fromWidth * 3;
                start = (uint8*)((addr_t)start + params.toBytesPerRow);
        }
}


static void
blit32(const BlitParameters& params)
{
        const uint8* data = params.from;
        data += (params.fromWidth * params.fromTop + params.fromLeft) * 3;
        uint32* start = (uint32*)(params.to
                + params.toBytesPerRow * params.toTop
                + 4 * params.toLeft);

        for (int32 y = params.fromTop; y < params.fromBottom; y++) {
                const uint8* src = data;
                uint32* dst = start;
                for (int32 x = params.fromLeft; x < params.fromRight; x++) {
                        dst[0] = (src[2] << 16) | (src[1] << 8) | (src[0]);
                        dst++;
                        src += 3;
                }

                data += params.fromWidth * 3;
                start = (uint32*)((addr_t)start + params.toBytesPerRow);
        }
}


static void
blit(const BlitParameters& params, int32 depth)
{
        switch (depth) {
                case 8:
                        blit8(params);
                        return;
                case 15:
                        blit15(params);
                        return;
                case 16:
                        blit16(params);
                        return;
                case 24:
                        blit24(params);
                        return;
                case 32:
                        blit32(params);
                        return;
        }
}


#endif  /* GENERIC_BLITTER_H */