windowscodecs: Add support for generating WICBitmapPaletteTypeFixedHalftone27 palette.

dlls/windowscodecs/palette.c

@@ -160,6 +160,28 @@ static WICColor *generate_halftone8_palette(UINT *count)
     return entries;
 }
 
+static WICColor *generate_halftone27_palette(UINT *count)
+{
+    WICColor *entries;
+    UINT i;
+
+    *count = 28;
+    entries = HeapAlloc(GetProcessHeap(), 0, 28 * sizeof(WICColor));
+    if (!entries) return NULL;
+
+    for (i = 0; i < 27; i++)
+    {
+        static const BYTE halftone_values[4] = { 0x00,0x80,0xff };
+        entries[i] = 0xff000000;
+        entries[i] |= halftone_values[i%3];
+        entries[i] |= halftone_values[(i/3)%3] << 8;
+        entries[i] |= halftone_values[(i/9)%3] << 16;
+    }
+
+    entries[i] = 0xffc0c0c0;
+    return entries;
+}
+
 static WICColor *generate_halftone64_palette(UINT *count)
 {
     WICColor *entries;
@@ -253,6 +275,11 @@ static HRESULT WINAPI PaletteImpl_InitializePredefined(IWICPalette *iface,
         if (!colors) return E_OUTOFMEMORY;
         break;
 
+    case WICBitmapPaletteTypeFixedHalftone27:
+        colors = generate_halftone27_palette(&count);
+        if (!colors) return E_OUTOFMEMORY;
+        break;
+
     case WICBitmapPaletteTypeFixedHalftone64:
         colors = generate_halftone64_palette(&count);
         if (!colors) return E_OUTOFMEMORY;

dlls/windowscodecs/tests/palette.c

@@ -199,6 +199,24 @@ static void generate_halftone8_palette(DWORD *entries, UINT count)
     }
 }
 
+static void generate_halftone27_palette(DWORD *entries, UINT count)
+{
+    static const BYTE halftone_values[4] = { 0x00,0x80,0xff };
+    UINT i;
+
+    assert(count == 28);
+
+    for (i = 0; i < 27; i++)
+    {
+        entries[i] = 0xff000000;
+        entries[i] |= halftone_values[i%3];
+        entries[i] |= halftone_values[(i/3)%3] << 8;
+        entries[i] |= halftone_values[(i/9)%3] << 16;
+    }
+
+    entries[i] = 0xffc0c0c0;
+}
+
 static void generate_halftone64_palette(DWORD *entries, UINT count)
 {
     static const BYTE halftone_values[4] = { 0x00,0x55,0xaa,0xff };
@@ -256,6 +274,7 @@ static void test_predefined_palette(void)
         { WICBitmapPaletteTypeFixedGray16, 0, 1, 16, { 0 } },
         { WICBitmapPaletteTypeFixedGray256, 0, 1, 256, { 0 } },
         { WICBitmapPaletteTypeFixedHalftone8, 0, 0, 16, { 0 } },
+        { WICBitmapPaletteTypeFixedHalftone27, 0, 0, 28, { 0 } },
         { WICBitmapPaletteTypeFixedHalftone64, 0, 0, 72, { 0 } },
         { WICBitmapPaletteTypeFixedHalftone256, 0, 0, 256, { 0 } },
     };
@@ -314,6 +333,8 @@ static void test_predefined_palette(void)
                 generate_gray256_palette(td[i].color, td[i].count);
             else if (td[i].type == WICBitmapPaletteTypeFixedHalftone8)
                 generate_halftone8_palette(td[i].color, td[i].count);
+            else if (td[i].type == WICBitmapPaletteTypeFixedHalftone27)
+                generate_halftone27_palette(td[i].color, td[i].count);
             else if (td[i].type == WICBitmapPaletteTypeFixedHalftone64)
                 generate_halftone64_palette(td[i].color, td[i].count);
             else if (td[i].type == WICBitmapPaletteTypeFixedHalftone256)