frontend: Fix colorspace conversion routines on big-endian

The bgr555_to_rgb565() and bgr888_to_rgb565() functions were only
working correctly on little-endian systems.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>

diff --git a/frontend/cspace.c b/frontend/cspace.c
index 55d4ac6..557fe46 100644 (file)
--- a/frontend/cspace.c
+++ b/frontend/cspace.c
@@ -15,21 +15,30 @@
  * in favor of NEON version or platform-specific conversion
  */
 
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#define SWAP16(x) __builtin_bswap16(x)
+#define LE16TOHx2(x) ((SWAP16((x) >> 16) << 16) | SWAP16(x))
+#else
+#define LE16TOHx2(x) (x)
+#endif
+
 #ifndef __arm__
 
 void bgr555_to_rgb565(void *dst_, const void *src_, int bytes)
 {
-       const unsigned int *src = src_;
-       unsigned int *dst = dst_;
-       unsigned int p;
-       int x;
-
-       for (x = 0; x < bytes / 4; x++) {
-               p = src[x];
-               p = ((p & 0x7c007c00) >> 10) | ((p & 0x03e003e0) << 1)
-                       | ((p & 0x001f001f) << 11);
-               dst[x] = p;
-       }
+    const unsigned int *src = src_;
+    unsigned int *dst = dst_;
+    unsigned int x, p, r, g, b;
+
+    for (x = 0; x < bytes / 4; x++) {
+        p = LE16TOHx2(src[x]);
+
+        r = (p & 0x001f001f) << 11;
+        g = (p & 0x03e003e0) << 1;
+        b = (p & 0x7c007c00) >> 10;
+
+        dst[x] = r | g | b;
+    }
 }
 
 #endif
@@ -71,8 +80,13 @@ void bgr888_to_rgb565(void *dst_, const void *src_, int bytes)
         r2 = src[3] & 0xf8;
         g2 = src[4] & 0xfc;
         b2 = src[5] & 0xf8;
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+        *dst = (r1 << 24) | (g1 << 19) | (b1 << 13) |
+               (r2 << 8) | (g2 << 3) | (b2 >> 3);
+#else
         *dst = (r2 << 24) | (g2 << 19) | (b2 << 13) |
                (r1 << 8) | (g1 << 3) | (b1 >> 3);
+#endif
     }
 }