2010-02-05 01:30 UTC+0200 Mindaugas Kavaliauskas (dbtopas/at/dbtopas.lt)

+ harbour/contrib/hbcairo/tests/lightning.prg
    + one more simple image generator sample

harbour/ChangeLog

@@ -17,6 +17,10 @@
    past entries belonging to author(s): Viktor Szakats.
 */
 
+2010-02-05 01:30 UTC+0200 Mindaugas Kavaliauskas (dbtopas/at/dbtopas.lt)
+  + harbour/contrib/hbcairo/tests/lightning.prg
+    + one more simple image generator sample
+
 2010-02-04 22:23 UTC+0100 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
   * harbour/src/vm/task.c
   * harbour/src/vm/classes.c

harbour/contrib/hbcairo/tests/lightning.prg

@@ -0,0 +1,63 @@
+/*
+ * $Id$
+ */
+
+
+#include "hbcairo.ch"
+
+
+PROC main()
+   LOCAL hSurface, hCairo, nI
+
+   hSurface := cairo_pdf_surface_create( "lightning.pdf", 566.9, 793.7 )  // 200x280 mm in pt
+   hCairo := cairo_create( hSurface )
+
+   // 20 pages
+   FOR nI := 1 TO 20
+     cairo_set_source_rgb( hCairo, 0, 0, 0 ) 
+     cairo_paint( hCairo )
+     cairo_set_source_rgb( hCairo, 1, 0.7, 1 ) 
+     DrawLightning( hCairo, 250, 50, 700, 3 )
+     cairo_show_page( hCairo )
+   NEXT
+   cairo_destroy( hCairo )
+   cairo_surface_destroy( hSurface )
+RETURN
+
+
+PROC DrawLightning( hCairo, nX, nY, nLen, nW, nInit )
+   LOCAL nI, nK, nW0, nX2
+
+   cairo_move_to( hCairo, nX, nY )
+   nW0 := nW
+   IF nInit == NIL
+      nInit := 0
+   ENDIF
+   nK := 0
+   FOR nI := 1 TO nLen
+     // AR(1) process
+     nInit := nInit * 0.9 + (hb_random() - 0.5)
+     // ARIMA(1, 1, 0) process
+     nK += nInit 
+     // ARIMA(1, 1, 0) + white noise
+     nX2 := nX + nK + hb_random()
+     cairo_line_to( hCairo, nX2, nI + nY )
+     nW -= 0.003
+     IF nW < nW0 - 0.1
+        cairo_set_line_width( hCairo, nW0 )
+        cairo_stroke( hCairo )
+        cairo_move_to( hCairo, nX2, nI + nY )
+        nW0 := nW
+     ENDIF
+     // Branch
+     IF ABS(nInit) > 1.6
+        cairo_set_line_width( hCairo, nW0 )
+        cairo_stroke( hCairo )
+        DrawLightning( hCairo, nX2, nI + nY, INT((nLen - nI) / 2), nW / 2, nInit * 0.5 )
+        nInit *= -0.3
+        cairo_move_to( hCairo, nX2, nI + nY )
+     ENDIF
+   NEXT
+   cairo_set_line_width( hCairo, nW0 )
+   cairo_stroke( hCairo )
+RETURN