[Pixman] [PATCH 3/4] Changed PIXMAN_KERNEL enums

[Bill Spitzak]

Added TENT filter.

Renamed other values to match what they are now producing.

Add back-compatibility #define for old names.
---
 demos/scale.c          |    7 ++++---
 pixman/pixman-filter.c |   41 +++++++++++++++++++++++++++++++++--------
 pixman/pixman.h        |   14 ++++++++++----
 3 files changed, 47 insertions(+), 15 deletions(-)

diff --git a/demos/scale.c b/demos/scale.c
index 0b6c715..deba8f1 100644
--- a/demos/scale.c
+++ b/demos/scale.c
@@ -73,11 +73,12 @@ static const named_int_t filters[] =
     { "Box",			PIXMAN_KERNEL_BOX },
     { "Impulse",		PIXMAN_KERNEL_IMPULSE },
     { "Linear",			PIXMAN_KERNEL_LINEAR },
-    { "Cubic",			PIXMAN_KERNEL_CUBIC },
-    { "Lanczos2",		PIXMAN_KERNEL_LANCZOS2 },
+    { "Tent",			PIXMAN_KERNEL_TENT },
+    { "Mitchell",		PIXMAN_KERNEL_MITCHELL },
+    { "Catmull-Rom",		PIXMAN_KERNEL_CATMULL_ROM },
     { "Lanczos3",		PIXMAN_KERNEL_LANCZOS3 },
     { "Lanczos3 Stretched",	PIXMAN_KERNEL_LANCZOS3_STRETCHED },
-    { "Gaussian",		PIXMAN_KERNEL_GAUSSIAN },
+    { "Notch",			PIXMAN_KERNEL_NOTCH },
 };
 
 static const named_int_t repeats[] =
diff --git a/pixman/pixman-filter.c b/pixman/pixman-filter.c
index f75bbd1..bd780e5 100644
--- a/pixman/pixman-filter.c
+++ b/pixman/pixman-filter.c
@@ -250,17 +250,42 @@ nice_width (double r)
     return MAX (2.0, ceil (r * 8));
 }
 
+/* PIXMAN_KERNEL_TENT: Triangle of width 2r. Lots of software uses
+   this as a "better" filter, twice the size of a box but smaller than
+   a cubic.
+
+   When r == 1.0, PIXMAN_KERNEL_BOX, PIXMAN_KERNEL_LINEAR, and
+   PIXMAN_KERNEL_TENT all produce the same filter, allowing
+   them to be exchanged at this point.
+*/
+
+static double
+tent_kernel (double x, double r)
+{
+    if (r < 1.0)
+	return box_kernel(x, r);
+    else
+	return MAX (1.0 - fabs(x / r), 0.0);
+}
+
+static int
+tent_width (double r)
+{
+    return r < 1.0 ? 2 : ceil(2 * r);
+}
+
 
 static const filter_info_t filters[] =
 {
-    { PIXMAN_KERNEL_IMPULSE,	        impulse_kernel,   impulse_width },
-    { PIXMAN_KERNEL_BOX,	        box_kernel,       box_width },
-    { PIXMAN_KERNEL_LINEAR,	        linear_kernel,    linear_width },
-    { PIXMAN_KERNEL_CUBIC,		mitchell_kernel,  cubic_width },
-    { PIXMAN_KERNEL_GAUSSIAN,	        notch_kernel,     cubic_width },
-    { PIXMAN_KERNEL_LANCZOS2,	        cubic_kernel,     cubic_width },
-    { PIXMAN_KERNEL_LANCZOS3,	        lanczos3_kernel,  lanczos3_width },
-    { PIXMAN_KERNEL_LANCZOS3_STRETCHED, nice_kernel,      nice_width },
+    { PIXMAN_KERNEL_IMPULSE,		impulse_kernel,   impulse_width },
+    { PIXMAN_KERNEL_BOX,		box_kernel,       box_width },
+    { PIXMAN_KERNEL_LINEAR,		linear_kernel,    linear_width },
+    { PIXMAN_KERNEL_MITCHELL,		mitchell_kernel,  cubic_width },
+    { PIXMAN_KERNEL_NOTCH,		notch_kernel,     cubic_width },
+    { PIXMAN_KERNEL_CATMULL_ROM,	cubic_kernel,     cubic_width },
+    { PIXMAN_KERNEL_LANCZOS3,		lanczos3_kernel,  lanczos3_width },
+    { PIXMAN_KERNEL_LANCZOS3_STRETCHED,	nice_kernel,      nice_width },
+    { PIXMAN_KERNEL_TENT,		tent_kernel,	  tent_width }
 };
 
 
diff --git a/pixman/pixman.h b/pixman/pixman.h
index 509ba5e..7af49d4 100644
--- a/pixman/pixman.h
+++ b/pixman/pixman.h
@@ -837,13 +837,19 @@ typedef enum
     PIXMAN_KERNEL_IMPULSE,
     PIXMAN_KERNEL_BOX,
     PIXMAN_KERNEL_LINEAR,
-    PIXMAN_KERNEL_CUBIC,
-    PIXMAN_KERNEL_GAUSSIAN,
-    PIXMAN_KERNEL_LANCZOS2,
+    PIXMAN_KERNEL_MITCHELL,
+    PIXMAN_KERNEL_NOTCH,
+    PIXMAN_KERNEL_CATMULL_ROM,
     PIXMAN_KERNEL_LANCZOS3,
-    PIXMAN_KERNEL_LANCZOS3_STRETCHED       /* Jim Blinn's 'nice' filter */
+    PIXMAN_KERNEL_LANCZOS3_STRETCHED,	/* Jim Blinn's 'nice' filter */
+    PIXMAN_KERNEL_TENT
 } pixman_kernel_t;
 
+/* Back-compatibility enums, do not use: */
+#define PIXMAN_KERNEL_CUBIC	PIXMAN_KERNEL_MITCHELL
+#define PIXMAN_KERNEL_LANCZOS2	PIXMAN_KERNEL_CATMULL_ROM
+#define PIXMAN_KERNEL_GAUSSIAN	PIXMAN_KERNEL_NOTCH
+
 /* Create the parameter list for a SEPARABLE_CONVOLUTION filter
  * with the given kernels and scale parameters.
  */
-- 
1.7.9.5