/* FreeRDP: A Remote Desktop Protocol Client
 * YCoCg<->RGB Color conversion operations.
 * vi:ts=4 sw=4:
 *
 * (c) Copyright 2014 Hewlett-Packard Development Company, L.P.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <freerdp/config.h>

#include <freerdp/types.h>
#include <freerdp/primitives.h>

#include "prim_internal.h"
#include "prim_YCoCg.h"

/* helper function to convert raw 8 bit values to signed 16bit values.
 */
static INT16 convert(UINT8 raw, int shift)
{
	const int cll = shift - 1; /* -1 builds in the /2's */
	return (INT16)((INT8)(raw << cll));
}

/* ------------------------------------------------------------------------- */
static pstatus_t general_YCoCgToRGB_8u_AC4R(const BYTE* WINPR_RESTRICT pSrc, INT32 srcStep,
                                            BYTE* WINPR_RESTRICT pDst, UINT32 DstFormat,
                                            INT32 dstStep, UINT32 width, UINT32 height, UINT8 shift,
                                            BOOL withAlpha)
{
	const DWORD formatSize = FreeRDPGetBytesPerPixel(DstFormat);
	fkt_writePixel writePixel = getPixelWriteFunction(DstFormat, TRUE);

	for (size_t y = 0; y < height; y++)
	{
		const BYTE* sptr = &pSrc[y * WINPR_ASSERTING_INT_CAST(uint32_t, srcStep)];
		BYTE* dptr = &pDst[y * WINPR_ASSERTING_INT_CAST(uint32_t, dstStep)];
		for (size_t x = 0; x < width; x++)
		{
			/* Note: shifts must be done before sign-conversion. */
			const INT16 Cg = convert(*sptr++, shift);
			const INT16 Co = convert(*sptr++, shift);
			const INT16 Y = *sptr++; /* UINT8->INT16 */
			const INT16 T = (INT16)(Y - Cg);
			const INT16 B = (INT16)(T + Co);
			const INT16 G = (INT16)(Y + Cg);
			const INT16 R = (INT16)(T - Co);
			BYTE A = *sptr++;

			if (!withAlpha)
				A = 0xFFU;

			dptr = writePixel(dptr, formatSize, DstFormat, CLIP(R), CLIP(G), CLIP(B), A);
		}
	}

	return PRIMITIVES_SUCCESS;
}

/* ------------------------------------------------------------------------- */
void primitives_init_YCoCg(primitives_t* WINPR_RESTRICT prims)
{
	prims->YCoCgToRGB_8u_AC4R = general_YCoCgToRGB_8u_AC4R;
}

void primitives_init_YCoCg_opt(primitives_t* WINPR_RESTRICT prims)
{
	primitives_init_YCoCg(prims);
	primitives_init_YCoCg_ssse3(prims);
	primitives_init_YCoCg_neon(prims);
}
