Some more conversion routines

1 files changed, 37 insertions, 24 deletions

diff --git a/pixman/pixman-utils.c b/pixman/pixman-utils.c
index 7393755..7f7285a 100644
--- a/pixman/pixman-utils.c
+++ b/pixman/pixman-utils.c
@@ -118,6 +118,31 @@ pixman_expand (uint64_t *           dst,
     }
 }
 
+static force_inline uint16_t
+float_to_unorm (float f, int n_bits)
+{
+    uint32_t u;
+
+    if (f > 1.0)
+	f = 1.0;
+    if (f < 0.0)
+	f = 0.0;
+
+    u = f * (1 << n_bits);
+    u -= (u >> n_bits);
+
+    return u;
+}
+
+
+static force_inline float
+unorm_to_float (uint16_t u, int n_bits)
+{
+    uint16_t m = ((1 << n_bits) - 1);
+
+    return (u & m) * (1 / (float)m);
+}
+
 void
 pixman_expand_to_float (argb_t               *dst,
 			const uint32_t       *src,
@@ -136,41 +161,29 @@ pixman_expand_to_float (argb_t               *dst,
               r_shift = 24 - r_size,
               g_shift = 16 - g_size,
               b_shift =  8 - b_size;
-    const uint8_t a_mask = ~(~0 << a_size),
-                  r_mask = ~(~0 << r_size),
-                  g_mask = ~(~0 << g_size),
-                  b_mask = ~(~0 << b_size);
     int i;
 
     for (i = 0; i < width; ++i)
     {
 	const uint32_t pixel = src[i];
-	const uint8_t a = (pixel >> a_shift) & a_mask,
-	              r = (pixel >> r_shift) & r_mask,
-	              g = (pixel >> g_shift) & g_mask,
-	              b = (pixel >> b_shift) & b_mask;
 
-	dst[i].a = a_size? a * (1 / ((1 << a_size) - 1.0)) : 1.0;
-	dst[i].r = r_size? r * (1 / ((1 << r_size) - 1.0)) : 0.0;
-	dst[i].g = g_size? g * (1 / ((1 << g_size) - 1.0)) : 0.0;
-	dst[i].b = b_size? b * (1 / ((1 << b_size) - 1.0)) : 0.0;
+	dst[i].a = a_size? unorm_to_float (pixel >> a_shift, a_size) : 1.0;
+	dst[i].r = r_size? unorm_to_float (pixel >> r_shift, r_size) : 0.0;
+	dst[i].g = g_size? unorm_to_float (pixel >> g_shift, g_size) : 0.0;
+	dst[i].b = b_size? unorm_to_float (pixel >> b_shift, b_size) : 0.0;
     }
 }
 
-static force_inline uint16_t
-float_to_unorm (float f, int n_bits)
+uint16_t
+pixman_float_to_unorm (float f, int n_bits)
 {
-    uint32_t u;
-
-    if (f > 1.0)
-	f = 1.0;
-    if (f < 0.0)
-	f = 0.0;
-
-    u = f * (1 << n_bits);
-    u -= (u >> n_bits);
+    return float_to_unorm (f, n_bits);
+}
 
-    return u;
+float
+pixman_unorm_to_float (uint16_t u, int n_bits)
+{
+    return unorm_to_float (u, n_bits);
 }
 
 void