Compute fixed_Max_int

1 files changed, 13 insertions, 5 deletions

diff --git a/dda.c b/dda.c
index 37eedbe..796b08d 100644
--- a/dda.c
+++ b/dda.c
@@ -4,19 +4,20 @@
 #include <stdint.h>
 #include "testdata.c"
 
-typedef uint32_t		fixed_t;
+typedef int32_t			fixed_t;
 
+#define FIXED_BITS		(8)
 
 #define fixed_e                 ((fixed_t) 1)
 #define fixed_1                 (int_to_fixed(1))
 #define fixed_1_minus_e         (fixed_1 - fixed_e)
-#define fixed_to_int(f)         ((int) ((f) >> 8))
-#define int_to_fixed(i)         ((fixed_t) ((i) << 8))
+#define fixed_to_int(f)         ((int) ((f) >> FIXED_BITS))
+#define int_to_fixed(i)         ((fixed_t) ((i) << FIXED_BITS))
 #define fixed_frac(f)           ((f) & fixed_1_minus_e)
 #define fixed_floor(f)          ((f) & ~fixed_1_minus_e)
 #define fixed_ceil(f)           fixed_floor ((f) + fixed_1_minus_e)
 #define fixed_mod_2(f)          ((f) & (fixed1 | fixed_1_minus_e))
-#define fixed_max_int           (0x7fffff)
+#define fixed_max_int           ((fixed_t)((0xffffffff << FIXED_BITS) & ~0x80000000))
 
 #define fixed_to_double(f)      ((double) ((f) * (1 / (double) fixed_1)))
 #define double_to_fixed(d)      ((fixed_t) ((d) * fixed_1))
@@ -195,7 +196,14 @@ edge_step (edge_t *edge, test_data_t *testdata, int i, int *yi)
     printf ("Pos: %f %f\n",
 	    fixed_to_double (sample_to_pos_x (edge->xi)),
 	    fixed_to_double (sample_to_pos_y (*yi)));
+#endif
+    printf ("Pos: %x %x\n", edge->xi, *yi);
+#if 0
+	    fixed_to_double (sample_to_pos_x (edge->xi)),
+	    fixed_to_double (sample_to_pos_y (*yi)));
+#endif
 
+#if 0
     if (testdata->points[i++] != sample_to_pos (edge->xi)		||
 	testdata->points[i++] != sample_to_pos (*yi))
     {
@@ -252,7 +260,7 @@ dda (test_data_t *testdata)
 int
 main ()
 {
-    test_data_t td = { { 0.5, 0.5, 3.5, 7.033 } };
+    test_data_t td = { { 0.5, 0.5, 3.5, 10.733 } };
 
     dda (&td);