code cleanup. don't use pointers when you don't have to. use const whereever you can.

(bzr r12077)

1 files changed, 13 insertions, 4 deletions

diff --git a/src/display/cairo-utils.h b/src/display/cairo-utils.h
index 04d6c6810..2596cd969 100644
--- a/src/display/cairo-utils.h
+++ b/src/display/cairo-utils.h
@@ -108,7 +108,7 @@ guint32 ink_cairo_surface_average_color(cairo_surface_t *surface);
 void ink_cairo_surface_average_color(cairo_surface_t *surface, double &r, double &g, double &b, double &a);
 void ink_cairo_surface_average_color_premul(cairo_surface_t *surface, double &r, double &g, double &b, double &a);
 
-void srgb_to_linear( double *c);
+double srgb_to_linear( const double c );
 int ink_cairo_surface_srgb_to_linear(cairo_surface_t *surface);
 int ink_cairo_surface_linear_to_srgb(cairo_surface_t *surface);
 
@@ -128,13 +128,13 @@ G_GNUC_CONST guint32 argb32_from_rgba(guint32 in);
 
 
 G_GNUC_CONST inline guint32
-premul_alpha(guint32 color, guint32 alpha)
+premul_alpha(const guint32 color, const guint32 alpha)
 {
-    guint32 temp = alpha * color + 128;
+    const guint32 temp = alpha * color + 128;
     return (temp + (temp >> 8)) >> 8;
 }
 G_GNUC_CONST inline guint32
-unpremul_alpha(guint32 color, guint32 alpha)
+unpremul_alpha(const guint32 color, const guint32 alpha)
 {
     // NOTE: you must check for alpha != 0 yourself.
     return (255 * color + alpha/2) / alpha;
@@ -154,6 +154,15 @@ void feed_pathvector_to_cairo (cairo_t *ct, Geom::PathVector const &pathv);
 #define ASSEMBLE_ARGB32(px,a,r,g,b) \
     guint32 px = (a << 24) | (r << 16) | (g << 8) | b;
 
+inline double srgb_to_linear( const double c ) {
+    if( c < 0.04045 ) {
+        return c / 12.92;
+    } else {
+        return pow( (c+0.055)/1.055, 2.4 );
+    }
+}
+
+
 namespace Inkscape {
 
 namespace Display