Ajout nouveaux tests

git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@708 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e

1 files changed, 148 insertions, 0 deletions

diff --git a/test/raytracer/surface.c b/test/raytracer/surface.c
new file mode 100644
index 00000000..0059db10
--- /dev/null
+++ b/test/raytracer/surface.c
@@ -0,0 +1,148 @@
+#include "config.h"
+#include "point.h"
+#include "vector.h"
+#include "eval.h"
+#include "object.h"
+#include "surface.h"
+
+/* Sphere:
+      x = sqrt(1 - y^2) sin(360u)
+      y = 2v - 1
+      z = sqrt(1 - y^2) cos(360u)
+   hence v = (y+1)/2
+     and u = atan2_turns(x, z) (atan2 in "number of turns")
+*/
+
+#define INV2PI (1.0 / (2.0 * M_PI))
+
+static inline flt atan2_turns(flt x, flt z)
+{
+  flt r = atan2(x, z) * INV2PI;
+  if (r < 0.0) r += 1.0;
+  return r;
+}
+
+static inline void sphere_coords(flt x, flt y, flt z,
+                                 int * face, flt * u, flt * v)
+{
+  *face = 0;
+  *u = atan2_turns(x, z);
+  *v = (y + 1.0) * 0.5;
+}
+
+/* Cube:
+     (x, y, 0)  ->  (0, x, y)
+     (x, y, 1)  ->  (1, x, y)
+     (0, y, z)  ->  (2, z, y)
+     (1, y, z)  ->  (3, z, y)
+     (x, 1, z)  ->  (4, x, z)
+     (x, 0, z)  ->  (5, x, z)
+   Watch out for rounding errors when determining which coordinate is 0 or 1;
+   see which one is closest to 0 or 1 */
+
+static inline void cube_coords(flt x, flt y, flt z,
+                               int * face, flt * u, flt * v)
+{
+  flt dists[6] =
+  { fabs(z), fabs(1 - z), fabs(x), fabs(1 - x), fabs(y), fabs(1 - y) };
+  flt min;
+  int f, i;
+
+  f = 0; min = dists[0];
+  for (i = 1; i < 6; i++)
+    if (dists[i] < min) { min = dists[i]; f = i; }
+  *face = f;
+  switch (f) {
+  case 0: case 1:
+    *u = x; *v = y; break;
+  case 2: case 3:
+    *u = z; *v = y; break;
+  case 4: case 5:
+    *u = x; *v = z; break;
+  }
+}
+
+/* Cylinder:
+     (x, 0, z)  ->  (2, u, v) where x = 2u-1 and z = 2v-1 hence
+     (x, 1, z)  ->  (1, x, z)   u = (x+1)/2 and v = (z+1)/2
+     (x, y, z)  ->  (0, u, v) where x = sin(360u)  v = y  z = cos(360u)
+                              hence u = atan2_turns(x, z)  and v = y
+*/
+
+static inline void cylinder_coords(flt x, flt y, flt z,
+                                   int * face, flt * u, flt * v)
+{
+  flt min, d;
+  int f;
+
+  min = y * y; f = 0;
+  d = (1 - y) * (1 - y);
+  if (d < min) { min = d; f = 1; }
+  d = fabs(x * x + z * z - 1);
+  if (d < min) { min = d; f = 2; }
+  *face = 2 - f;
+  if (f < 2) {
+    *u = (x + 1) * 0.5;
+    *v = (z + 1) * 0.5;
+  } else {
+    *u = atan2_turns(x, z);
+    *v = y;
+  }
+}
+
+/* Cone:
+     (x, y, z)  ->  (0, u, v)  where x = v sin 360u
+                                     y = v
+                                     z = v cos 360u
+                               hence u = atan2_turns(x, z) and v = y
+     (x, 1, z)  ->  (1, u, v)  where x = 2u-1 and z = 2v-1
+                               hence u = (x+1)/2 and v = (z+1)/2
+*/
+
+static inline void cone_coords(flt x, flt y, flt z,
+                               int * face, flt * u, flt * v)
+{
+  if ((1 - y) * (1 - y) < fabs(x * x + z * z - y * y)) {
+    *face = 1;
+    *u = (x + 1) * 0.5;
+    *v = (z + 1) * 0.5;
+  } else {
+    *face = 0;
+    *u = atan2_turns(x, z);
+    *v = y;
+  }
+}
+
+/* Plane */
+
+static inline void plane_coords(flt x, flt y, flt z,
+                                int * face, flt * u, flt * v)
+{
+  *face = 0;
+  *u = x;
+  *v = z;
+}
+
+/* All together */
+
+void surface_coords(struct object * obj, struct point * p,
+                    /*out*/ int * face,
+                    /*out*/ flt * u,
+                    /*out*/ flt * v)
+{
+  switch (obj->kind) {
+  case Cone:
+    cone_coords(p->x, p->y, p->z, face, u, v); break;
+  case Cube:
+    cube_coords(p->x, p->y, p->z, face, u, v); break;
+  case Cylinder:
+    cylinder_coords(p->x, p->y, p->z, face, u, v); break;
+  case Plane:
+    plane_coords(p->x, p->y, p->z, face, u, v); break;
+  case Sphere:
+    sphere_coords(p->x, p->y, p->z, face, u, v); break;
+  default:
+    assert(0);
+  }
+}
+