From 812d03129dea53337367789bac8ab523b9fce21d Mon Sep 17 00:00:00 2001
From: Dmitry Timoshkov <dmitry@baikal.ru>
Date: Thu, 21 Feb 2019 09:24:54 +0300
Subject: [PATCH] windowscodecs: Add support for CMYK to BGR conversion.

Signed-off-by: Dmitry Timoshkov <dmitry@baikal.ru>
Signed-off-by: Vincent Povirk <vincent@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>
---
 dlls/windowscodecs/converter.c | 43 ++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/dlls/windowscodecs/converter.c b/dlls/windowscodecs/converter.c
index 9083aa04f73..3b3030bfc49 100644
--- a/dlls/windowscodecs/converter.c
+++ b/dlls/windowscodecs/converter.c
@@ -30,6 +30,7 @@
 
 #include "wincodecs_private.h"
 
+#include "wine/heap.h"
 #include "wine/debug.h"
 
 WINE_DEFAULT_DEBUG_CHANNEL(wincodecs);
@@ -1121,6 +1122,48 @@ static HRESULT copypixels_to_24bppBGR(struct FormatConverter *This, const WICRec
         }
         return S_OK;
 
+    case format_32bppCMYK:
+        if (prc)
+        {
+            BYTE *srcdata;
+            UINT srcstride, srcdatasize;
+
+            srcstride = 4 * prc->Width;
+            srcdatasize = srcstride * prc->Height;
+
+            srcdata = heap_alloc(srcdatasize);
+            if (!srcdata) return E_OUTOFMEMORY;
+
+            hr = IWICBitmapSource_CopyPixels(This->source, prc, srcstride, srcdatasize, srcdata);
+            if (SUCCEEDED(hr))
+            {
+                INT x, y;
+                BYTE *src = srcdata, *dst = pbBuffer;
+
+                for (y = 0; y < prc->Height; y++)
+                {
+                    BYTE *cmyk = src;
+                    BYTE *bgr = dst;
+
+                    for (x = 0; x < prc->Width; x++)
+                    {
+                        BYTE c = cmyk[0], m = cmyk[1], y = cmyk[2], k = cmyk[3];
+                        bgr[0] = (255 - y) * (255 - k) / 255; /* B */
+                        bgr[1] = (255 - m) * (255 - k) / 255; /* G */
+                        bgr[2] = (255 - c) * (255 - k) / 255; /* R */
+                        cmyk += 4;
+                        bgr += 3;
+                    }
+                    src += srcstride;
+                    dst += cbStride;
+                }
+            }
+
+            heap_free(srcdata);
+            return hr;
+        }
+        return S_OK;
+
     default:
         FIXME("Unimplemented conversion path!\n");
         return WINCODEC_ERR_UNSUPPORTEDOPERATION;