Added function to calculate bounds of a polygon.

SVN revision: 3280

src/Imlib2.h

@@ -249,6 +249,7 @@ ImlibPolygon imlib_polygon_new(int type);
 void imlib_polygon_free(ImlibPolygon poly);
 void imlib_polygon_add_point(ImlibPolygon poly, int x, int y);
 void imlib_image_draw_polygon(ImlibPolygon poly);
+void imlib_polygon_get_bounds(ImlibPolygon poly, int *px1, int *py1, int *px2, int *py2);
 
 Imlib_Color_Range imlib_create_color_range(void);
 void imlib_free_color_range(void);

src/api.c

@@ -2748,3 +2748,9 @@ void imlib_image_draw_polygon(ImlibPolygon poly)
                    ctxt_color.blue, ctxt_color.alpha, ctxt_operation);
    }
 }
+
+void imlib_polygon_get_bounds(ImlibPolygon poly, int *px1, int *py1, int *px2, int *py2)
+{
+   CHECK_PARAM_POINTER("imlib_polygon_get_bounds", "polygon", poly);
+   __imlib_polygon_get_bounds(poly, px1, py1, px2, py2);
+}

src/rgbadraw.c

@@ -1705,3 +1705,18 @@ __imlib_draw_polygon_clipped(ImlibImage * im, ImlibPoly poly, int clip_xmin,
    }
 }
 
+void __imlib_polygon_get_bounds(ImlibPoly poly, int *px1, int *py1, int *px2, int *py2)
+{
+   int x1,y1,x2,y2;
+   int i;
+  if(!poly || !poly->points || (poly->pointcount < 2))
+      return;
+  
+  for(i = 0; i < poly->pointcount; i++)
+     GROW_BOUNDS (x1, y1, x2, y2, poly->points[i].x, poly->points[i].y);
+
+    *px1 = x1;
+    *py1 = y1;
+    *px2 = x2;
+    *py2 = y2;
+}

src/rgbadraw.h

@@ -1,6 +1,22 @@
 #ifndef __RGBADRAW
 #define __RGBADRAW 1
 
+
+#define GROW_BOUNDS(px1, py1, px2, py2, x, y) { \
+    if (x < px1)      \
+        px1 = x;      \
+                      \
+    if (x > px2)      \
+        px2 = x;      \
+                      \
+    if (y < py1)      \
+        py1 = y;      \
+                      \
+    if (y > py2)      \
+        py2 = y;      \
+}   
+
+
 typedef struct _imlib_point    ImlibPoint;
 
 struct _imlib_point
@@ -76,4 +92,5 @@ void
 __imlib_draw_polygon_clipped(ImlibImage * im, ImlibPoly poly, int clip_xmin,
    int clip_xmax, int clip_ymin, int clip_ymax, DATA8 r, DATA8 g,  DATA8 b,
    DATA8 a, ImlibOp op);
+void __imlib_polygon_get_bounds(ImlibPoly poly, int *px1, int *py1, int *px2, int *py2);
 #endif