FreeRDP/libfreerdp/primitives/prim_alphaComp.c
Martin Fleisz 343d210a75 primitives: separating optimized functions into their own .c files.
This way we use certain compiler flags (like -msse3) only on files
containing optimized code. This avoids problems that occured when
using these flags compiling generic code and running it on platforms
that don't support these optimizations (i.e. NEON optimization on
ARM platforms).
2013-02-21 02:45:10 -08:00

118 lines
3.4 KiB
C

/* FreeRDP: A Remote Desktop Protocol Client
* Alpha blending routines.
* vi:ts=4 sw=4:
*
* (c) Copyright 2012 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.
*
* Note: this code assumes the second operand is fully opaque,
* e.g.
* newval = alpha1*val1 + (1-alpha1)*val2
* rather than
* newval = alpha1*val1 + (1-alpha1)*alpha2*val2
* The IPP gives other options.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <freerdp/types.h>
#include <freerdp/primitives.h>
#include "prim_internal.h"
#include "prim_alphaComp.h"
#define ALPHA(_k_) (((_k_) & 0xFF000000U) >> 24)
#define RED(_k_) (((_k_) & 0x00FF0000U) >> 16)
#define GRN(_k_) (((_k_) & 0x0000FF00U) >> 8)
#define BLU(_k_) (((_k_) & 0x000000FFU))
/* ------------------------------------------------------------------------- */
pstatus_t general_alphaComp_argb(
const BYTE *pSrc1, INT32 src1Step,
const BYTE *pSrc2, INT32 src2Step,
BYTE *pDst, INT32 dstStep,
INT32 width, INT32 height)
{
const UINT32 *sptr1 = (const UINT32 *) pSrc1;
const UINT32 *sptr2 = (const UINT32 *) pSrc2;
UINT32 *dptr = (UINT32 *) pDst;
int linebytes = width * sizeof(UINT32);
int src1Jump = (src1Step - linebytes) / sizeof(UINT32);
int src2Jump = (src2Step - linebytes) / sizeof(UINT32);
int dstJump = (dstStep - linebytes) / sizeof(UINT32);
int y;
for (y=0; y<height; y++)
{
int x;
for (x=0; x<width; x++)
{
const UINT32 src1 = *sptr1++;
const UINT32 src2 = *sptr2++;
UINT32 alpha = ALPHA(src1) + 1;
if (alpha == 256)
{
/* If alpha is 255+1, just copy src1. */
*dptr++ = src1;
}
else if (alpha <= 1)
{
/* If alpha is 0+1, just copy src2. */
*dptr++ = src2;
}
else
{
/* A perfectly accurate blend would do (a*src + (255-a)*dst)/255
* rather than adding one to alpha and dividing by 256, but this
* is much faster and only differs by one 16% of the time.
* I'm not sure who first designed the double-ops trick
* (Red Blue and Alpha Green).
*/
UINT32 rb, ag;
UINT32 s2rb = src2 & 0x00FF00FFU;
UINT32 s2ag = (src2 >> 8) & 0x00FF00FFU;
UINT32 s1rb = src1 & 0x00FF00FFU;
UINT32 s1ag = (src1 >> 8) & 0x00FF00FFU;
UINT32 drb = s1rb - s2rb;
UINT32 dag = s1ag - s2ag;
drb *= alpha;
dag *= alpha;
rb = ((drb >> 8) + s2rb) & 0x00FF00FFU;
ag = (((dag >> 8) + s2ag) << 8) & 0xFF00FF00U;
*dptr++ = rb | ag;
}
}
sptr1 += src1Jump;
sptr2 += src2Jump;
dptr += dstJump;
}
return PRIMITIVES_SUCCESS;
}
/* ------------------------------------------------------------------------- */
void primitives_init_alphaComp(const primitives_hints_t* hints, primitives_t* prims)
{
prims->alphaComp_argb = general_alphaComp_argb;
primitives_init_alphaComp_opt(hints, prims);
}
/* ------------------------------------------------------------------------- */
void primitives_deinit_alphaComp(primitives_t *prims)
{
/* Nothing to do. */
}