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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 01:24:41 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 01:24:41 +0000
commita9bcc81f821d7c66f623779fa5147e728eb3c388 (patch)
tree98676963bcdd537ae5908a067a8eb110b93486a6 /libfreerdp/primitives/prim_alphaComp.c
parentInitial commit. (diff)
downloadfreerdp3-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.c94
1 files changed, 94 insertions, 0 deletions
diff --git a/libfreerdp/primitives/prim_alphaComp.c b/libfreerdp/primitives/prim_alphaComp.c
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+/* 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;
+}