Fix some MSVC /W4 warnings

stb_image_resize.h

@@ -552,9 +552,9 @@ typedef struct
 } stbir__info;
 
 
-static const double stbir__max_uint8_as_float  = 255.0f;
-static const double stbir__max_uint16_as_float = 65535.0f;
-static const double stbir__max_uint32_as_float = 4294967295.0f;
+static const float stbir__max_uint8_as_float  = 255.0f;
+static const float stbir__max_uint16_as_float = 65535.0f;
+static const double stbir__max_uint32_as_float = 4294967295.0;
 
 
 static stbir__inline int stbir__min(int a, int b)
@@ -1713,9 +1713,13 @@ static void stbir__encode_scanline(stbir__info* stbir_info, int num_pixels, void
 
     // build a table of all channels that need colorspace correction, so
     // we don't perform colorspace correction on channels that don't need it.
-    for (x=0, num_nonalpha=0; x < channels; ++x)
-        if (x != alpha_channel || (stbir_info->flags & STBIR_FLAG_ALPHA_USES_COLORSPACE))
-            nonalpha[num_nonalpha++] = x;
+	for (x = 0, num_nonalpha = 0; x < channels; ++x)
+	{
+		if (x != alpha_channel || (stbir_info->flags & STBIR_FLAG_ALPHA_USES_COLORSPACE))
+		{
+            nonalpha[num_nonalpha++] = (stbir_uint16)x;
+		}
+	}
 
     #define STBIR__ROUND_INT(f)    ((int)          ((f)+0.5))
     #define STBIR__ROUND_UINT(f)   ((stbir_uint32) ((f)+0.5))