Revision 147:3494792458d9, committed 2017-06-12

Comitter:

WiredHome

Date:

Mon Jun 12 22:15:08 2017 +0000

Parent:

146:373d59f08357

Child:

148:33e99de1aca6

Commit message:

Improved the Intersect(rect_t, rect_t) to look for any intersection, and added an Intersect(rect_t *, rect_t *) which will identify and make available a new rect_t which is the intersection (if any).

Changed in this revision

--- a/RA8875.cpp	Thu Jun 01 11:00:40 2017 +0000
+++ b/RA8875.cpp	Mon Jun 12 22:15:08 2017 +0000
@@ -525,20 +525,47 @@
 
 bool RA8875::Intersect(rect_t rect1, rect_t rect2)
 {
+#if 1
+    // If one rectangle is on left side of other
+    if (max(rect1.p1.x,rect1.p2.x) < min(rect2.p1.x,rect2.p2.x)
+        || min(rect1.p1.x, rect1.p2.x) > max(rect2.p1.x, rect2.p2.x))
+        return false;
+    // If one rectangle is above other
+    if (max(rect1.p1.y, rect1.p2.y) < min(rect2.p1.y, rect2.p2.y)
+        || min(rect1.p1.y, rect1.p2.y) > max(rect2.p1.y, rect2.p2.y))
+        return false;
+    return true;            // all that's left is they overlap
+#else
     point_t bl, tr;
-    
     bl.x = rect2.p1.x;
     bl.y = rect2.p2.y;
     tr.x = rect2.p2.x;
     tr.y = rect2.p1.y;
     if (Intersect(rect1, rect2.p1) || Intersect(rect1, rect2.p2)
-    || Intersect(rect1, bl) || Intersect(rect1, tr))
+        || Intersect(rect1, bl) || Intersect(rect1, tr))
         return true;
     else
         return false;
+#endif
 }
 
 
+bool RA8875::Intersect(rect_t * pRect1, const rect_t * pRect2)
+{
+    if (Intersect(*pRect1, *pRect2)) {
+        rect_t iSect;
+        
+        iSect.p1.x = max(pRect1->p1.x, pRect2->p1.x);
+        iSect.p1.y = max(pRect1->p1.y, pRect2->p1.y);
+        iSect.p2.x = min(pRect1->p2.x, pRect2->p2.x);
+        iSect.p2.y = min(pRect1->p2.y, pRect2->p2.y);
+        *pRect1 = iSect;
+        return true;
+    } else {
+        return false;
+    }
+}
+
 
 RetCode_t RA8875::WriteCommandW(uint8_t command, uint16_t data)
 {

--- a/RA8875.h	Thu Jun 01 11:00:40 2017 +0000
+++ b/RA8875.h	Mon Jun 12 22:15:08 2017 +0000
@@ -1163,10 +1163,36 @@
     ///
     /// @param[in] rect1 is a rectangular region.
     /// @param[in] rect2 is a second rectangular region.
-    /// @returns true if rect1 and rect2 intersect.
+    /// @returns true if any part of rect2 intersects rect1.
     ///
     bool Intersect(rect_t rect1, rect_t rect2);
     
+    /// Determine if a rectangle intersects another rectangle and provides
+    /// the area of intersection.
+    ///
+    /// @code
+    ///     +---------------------+
+    ///     | rect1               |
+    ///     |                     |
+    ///     |          +------------------+
+    ///     |          | rect3    |       |
+    ///     |          |          |       |
+    ///     +---------------------+       |
+    ///                | rect2            |
+    ///                +------------------+
+    /// @endcode
+    ///
+    /// @note that the first parameter is a pointer to a rect and the 
+    ///
+    /// @param[inout] pRect1 is a pointer to a rectangular region, and returns
+    ///             the area of intersection.
+    /// @param[in] pRect2 is a pointer to a second rectangular region.
+    /// @returns true if pRect1 and pRect2 intersect and pRect1 is written with
+    ///             the rectangle describing the intersection.
+    ///
+    bool Intersect(rect_t * rect1, const rect_t * rect2);
+    
+    
     /// Write a command to the display with a word of data.
     ///
     /// This is a high level command, and may invoke several primitives.