gallium/auxiliary: add contained and rect checks (v6)

v3: thanks to Brian, improved coding style, also glennk helped spot few
things (unsigned -> int, two constify)
v4: thanks Ilia improved function, dropped u_box_clip_3d
v5: incorporated rest of Gregor proposed changes,clean ups
v6: u_box_clip_2d simplify proposed by Ilia Mirkin

Acked-by: Jose Fonseca <jfonseca@vmware.com>
Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Signed-off-by: David Heidelberg <david@ixit.cz>

src/gallium/auxiliary/util/u_box.h

@@ -2,6 +2,7 @@
 #define UTIL_BOX_INLINES_H
 
 #include "pipe/p_state.h"
+#include "util/u_math.h"
 
 static INLINE
 void u_box_1d( unsigned x,
@@ -77,4 +78,121 @@ void u_box_3d( unsigned x,
    box->depth = d;
 }
 
+/* Clips @dst to width @w and height @h.
+ * Returns -1 if the resulting box would be empty (then @dst is left unchanged).
+ *          0 if nothing has been reduced.
+ *          1 if width has been reduced.
+ *          2 if height has been reduced.
+ *          3 if both width and height have been reduced.
+ * Aliasing permitted.
+ */
+static INLINE int
+u_box_clip_2d(struct pipe_box *dst,
+              const struct pipe_box *box, int w, int h)
+{
+   unsigned i;
+   int a[2], b[2], dim[2];
+   int *start, *end;
+   int res = 0;
+
+   if (!box->width || !box->height)
+      return -1;
+   dim[0] = w;
+   dim[1] = h;
+   a[0] = box->x;
+   a[1] = box->y;
+   b[0] = box->x + box->width;
+   b[1] = box->y + box->height;
+
+   for (i = 0; i < 2; ++i) {
+      start = (a[i] <= b[i]) ? &a[i] : &b[i];
+      end = (a[i] <= b[i]) ? &b[i] : &a[i];
+
+      if (*end < 0 || *start >= dim[i])
+         return -1;
+      if (*start < 0) {
+         *start = 0;
+         res |= (1 << i);
+      }
+      if (*end > dim[i]) {
+         *end = dim[i];
+         res |= (1 << i);
+      }
+   }
+
+   if (res) {
+      dst->x = a[0];
+      dst->y = a[1];
+      dst->width = b[0] - a[0];
+      dst->height = b[1] - a[1];
+   }
+   return res;
+}
+
+static INLINE int64_t
+u_box_volume_3d(const struct pipe_box *box)
+{
+   return (int64_t)box->width * box->height * box->depth;
+}
+
+/* Aliasing of @dst permitted. */
+static INLINE void
+u_box_union_2d(struct pipe_box *dst,
+               const struct pipe_box *a, const struct pipe_box *b)
+{
+   dst->x = MIN2(a->x, b->x);
+   dst->y = MIN2(a->y, b->y);
+
+   dst->width = MAX2(a->x + a->width, b->x + b->width) - dst->x;
+   dst->height = MAX2(a->y + a->height, b->y + b->height) - dst->y;
+}
+
+/* Aliasing of @dst permitted. */
+static INLINE void
+u_box_union_3d(struct pipe_box *dst,
+               const struct pipe_box *a, const struct pipe_box *b)
+{
+   dst->x = MIN2(a->x, b->x);
+   dst->y = MIN2(a->y, b->y);
+   dst->z = MIN2(a->z, b->z);
+
+   dst->width = MAX2(a->x + a->width, b->x + b->width) - dst->x;
+   dst->height = MAX2(a->y + a->height, b->y + b->height) - dst->y;
+   dst->depth = MAX2(a->z + a->depth, b->z + b->depth) - dst->z;
+}
+
+static INLINE boolean
+u_box_test_intersection_2d(const struct pipe_box *a,
+                           const struct pipe_box *b)
+{
+   unsigned i;
+   int a_l[2], a_r[2], b_l[2], b_r[2];
+
+   a_l[0] = MIN2(a->x, a->x + a->width);
+   a_r[0] = MAX2(a->x, a->x + a->width);
+   a_l[1] = MIN2(a->y, a->y + a->height);
+   a_r[1] = MAX2(a->y, a->y + a->height);
+
+   b_l[0] = MIN2(b->x, b->x + b->width);
+   b_r[0] = MAX2(b->x, b->x + b->width);
+   b_l[1] = MIN2(b->y, b->y + b->height);
+   b_r[1] = MAX2(b->y, b->y + b->height);
+
+   for (i = 0; i < 2; ++i) {
+      if (a_l[i] > b_r[i] || a_r[i] < b_l[i])
+         return FALSE;
+   }
+   return TRUE;
+}
+
+static INLINE void
+u_box_minify_2d(struct pipe_box *dst,
+                const struct pipe_box *src, unsigned l)
+{
+   dst->x = src->x >> l;
+   dst->y = src->y >> l;
+   dst->width = MAX2(src->width >> l, 1);
+   dst->height = MAX2(src->height >> l, 1);
+}
+
 #endif

src/gallium/auxiliary/util/u_rect.h

@@ -30,6 +30,7 @@
 #define U_RECT_H
 
 #include "pipe/p_compiler.h"
+#include "util/u_math.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -67,6 +68,12 @@ u_rect_find_intersection(const struct u_rect *a,
 }
 
 
+static INLINE int
+u_rect_area(const struct u_rect *r)
+{
+   return (r->x1 - r->x0) * (r->y1 - r->y0);
+}
+
 static INLINE void
 u_rect_possible_intersection(const struct u_rect *a,
                              struct u_rect *b)
@@ -79,6 +86,17 @@ u_rect_possible_intersection(const struct u_rect *a,
    }
 }
 
+/* Set @d to a rectangle that covers both @a and @b.
+ */
+static INLINE void
+u_rect_union(struct u_rect *d, const struct u_rect *a, const struct u_rect *b)
+{
+   d->x0 = MIN2(a->x0, b->x0);
+   d->y0 = MIN2(a->y0, b->y0);
+   d->x1 = MAX2(a->x1, b->x1);
+   d->y1 = MAX2(a->y1, b->y1);
+}
+
 #ifdef __cplusplus
 }
 #endif