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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 01:24:41 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 01:24:41 +0000 |
commit | a9bcc81f821d7c66f623779fa5147e728eb3c388 (patch) | |
tree | 98676963bcdd537ae5908a067a8eb110b93486a6 /libfreerdp/primitives/prim_alphaComp.c | |
parent | Initial commit. (diff) | |
download | freerdp3-a9bcc81f821d7c66f623779fa5147e728eb3c388.tar.xz freerdp3-a9bcc81f821d7c66f623779fa5147e728eb3c388.zip |
Adding upstream version 3.3.0+dfsg1.upstream/3.3.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'libfreerdp/primitives/prim_alphaComp.c')
-rw-r--r-- | libfreerdp/primitives/prim_alphaComp.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/libfreerdp/primitives/prim_alphaComp.c b/libfreerdp/primitives/prim_alphaComp.c new file mode 100644 index 0000000..fe4f8dc --- /dev/null +++ b/libfreerdp/primitives/prim_alphaComp.c @@ -0,0 +1,94 @@ +/* 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. + */ + +#include <freerdp/config.h> + +#include <freerdp/types.h> +#include <freerdp/primitives.h> + +#include "prim_internal.h" + +#define ALPHA(_k_) (((_k_)&0xFF000000U) >> 24) +#define RED(_k_) (((_k_)&0x00FF0000U) >> 16) +#define GRN(_k_) (((_k_)&0x0000FF00U) >> 8) +#define BLU(_k_) (((_k_)&0x000000FFU)) + +/* ------------------------------------------------------------------------- */ +static pstatus_t general_alphaComp_argb(const BYTE* pSrc1, UINT32 src1Step, const BYTE* pSrc2, + UINT32 src2Step, BYTE* pDst, UINT32 dstStep, UINT32 width, + UINT32 height) +{ + for (UINT32 y = 0; y < height; y++) + { + const UINT32* sptr1 = (const UINT32*)(pSrc1 + y * src1Step); + const UINT32* sptr2 = (const UINT32*)(pSrc2 + y * src2Step); + UINT32* dptr = (UINT32*)(pDst + y * dstStep); + + for (UINT32 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 = 0; + UINT32 ag = 0; + 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; + } + } + } + + return PRIMITIVES_SUCCESS; +} + +/* ------------------------------------------------------------------------- */ +void primitives_init_alphaComp(primitives_t* prims) +{ + prims->alphaComp_argb = general_alphaComp_argb; +} |