hide <ncursesw/ncurses.h> behind ncrswrap.*

isolate ct_dims implementation to dims.*

cursetree/dims.c

@@ -0,0 +1,59 @@
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "dims.h"
+
+struct ct_dims *new_dims(int x, int y, int width, int height) {
+  struct ct_dims *dims;
+
+  dims = (struct ct_dims *)malloc(sizeof(struct ct_dims));
+  *dims = (struct ct_dims){
+      .x = x,
+      .y = y,
+      .width = width,
+      .height = height,
+  };
+  return dims;
+}
+
+struct ct_dims *dup_dims(const struct ct_dims *const dims) {
+  struct ct_dims *dup;
+  dup = (struct ct_dims *)malloc(sizeof(struct ct_dims));
+  memcpy(dup, dims, sizeof(struct ct_dims));
+
+  return dup;
+}
+
+/* Calculate the dimensions for nodes resulting from a bifurcation.
+ * Returns 0 on success, and 1 on failure if any width/height are 0 characters.
+ * WARNING: This function does not guarantee the x,y positions returned
+ * WARNING: are valid screen coordinates.
+ */
+int bifurcate_dims(const struct ct_dims *const parent_dims,
+                   const enum ct_axis axis, const float ratio,
+                   struct ct_dims **const dims0, struct ct_dims **const dims1) {
+  assert(0 < ratio && ratio < 1);
+  struct ct_dims *_dims0, *_dims1;
+
+  _dims0 = dup_dims(parent_dims);
+  _dims1 = dup_dims(parent_dims);
+
+  if (axis == AXIS_X) {
+    _dims0->width *= ratio;
+    _dims1->width -= _dims0->width;
+    _dims1->x += _dims0->width;
+  } else {
+    _dims0->height *= ratio;
+    _dims1->height -= _dims0->height;
+    _dims1->y += _dims0->height;
+  }
+
+  if (!_dims0->width || !_dims0->height || !_dims1->width || !_dims1->height)
+    return 1;
+
+  // propagate bifurcated dimensions
+  *dims0 = _dims0;
+  *dims1 = _dims1;
+  return 0;
+}