[cairo-commit] pycairo/examples/gtk cairo-knockout.py,1.6,1.7

[Steve Chaplin]

Committed by: stevech1097

Update of /cvs/cairo/pycairo/examples/gtk
In directory gabe:/tmp/cvs-serv32284/examples/gtk

Modified Files:
	cairo-knockout.py 
Log Message:
SC

Index: cairo-knockout.py
===================================================================
RCS file: /cvs/cairo/pycairo/examples/gtk/cairo-knockout.py,v
retrieving revision 1.6
retrieving revision 1.7
diff -u -d -r1.6 -r1.7
--- cairo-knockout.py	9 May 2005 09:12:31 -0000	1.6
+++ cairo-knockout.py	11 May 2005 06:22:53 -0000	1.7
@@ -17,47 +17,26 @@
     ctx.translate (xc, yc)
     ctx.scale (1.0, yr / xr)
     ctx.move_to (xr, 0.0)
-    ctx.arc (  0, 0,
-               xr,
-               0, 2 * math.pi)
+    ctx.arc (0, 0, xr, 0, 2 * math.pi)
     ctx.close_path ()
 
     ctx.restore()
     
 def fill_checks(ctx, x, y, width, height):
-    # update to match testcairo.c
-    ctx.save()
-
     CHECK_SIZE = 32
-    check = ctx.target.create_similar(cairo.FORMAT_RGB24,
-                                      2*CHECK_SIZE, 2*CHECK_SIZE)
-    check.set_repeat(1)
-
-    ctx.save()
-    ctx.set_target_surface(check)
-    ctx.set_operator(cairo.OPERATOR_SRC)
-
-    ctx.set_source_rgb(0.4, 0.4, 0.4)
-    
-    ctx.rectangle(0, 0, 2*CHECK_SIZE, 2*CHECK_SIZE)
-    ctx.fill()
-
-    ctx.set_source_rgb(0.7, 0.7, 0.7)
-    
-    ctx.rectangle(x, y, CHECK_SIZE, CHECK_SIZE)
-    ctx.fill()
-    ctx.rectangle(x+CHECK_SIZE, y+CHECK_SIZE, CHECK_SIZE, CHECK_SIZE)
-    ctx.fill()
 
-    ctx.restore()
+    ctx.rectangle (x, y, width, height)
+    ctx.set_source_rgb (0.4, 0.4, 0.4)
+    ctx.fill ()
 
-    check_pattern = cairo.Pattern.create_for_surface (check)
-    ctx.set_source(check_pattern)
-    ctx.rectangle(0, 0, width, height)
-    ctx.fill()
+    # Only works for CHECK_SIZE a power of 2
+    for j in range (x & -CHECK_SIZE, height, CHECK_SIZE):
+        for i in range (y & -CHECK_SIZE, width, CHECK_SIZE):
+            if ((i / CHECK_SIZE + j / CHECK_SIZE) % 2 == 0):
+                ctx.rectangle (i, j, CHECK_SIZE, CHECK_SIZE)
 
-    ctx.restore()
-    
+    ctx.set_source_rgb (0.7, 0.7, 0.7)
+    ctx.fill ()
 
 def draw_3circles(ctx, xc, yc, radius, alpha):
     subradius = radius * (2 / 3. - 0.1)
@@ -83,7 +62,6 @@
               subradius, subradius)
     ctx.fill()
 
-
 def draw (ctx, width, height):
     radius = 0.5 * min(width, height) - 10
     xc = width / 2.
@@ -95,44 +73,35 @@
 
     fill_checks(ctx, 0, 0, width, height)
 
-    ctx.save()
-    ctx.set_target_surface(overlay)
-
     # Draw a black circle on the overlay
-    ctx.set_source_rgb(0, 0, 0)
-    oval_path(ctx, xc, yc, radius, radius)
-    ctx.fill()
-
-    ctx.save()
-    ctx.set_target_surface(punch)
+    overlay_cr = cairo.Context (overlay)
+    overlay_cr.set_source_rgb (0, 0, 0)
+    oval_path (overlay_cr, xc, yc, radius, radius)
+    overlay_cr.fill()
 
     # Draw 3 circles to the punch surface, then cut
     # that out of the main circle in the overlay
-    draw_3circles(ctx, xc, yc, radius, 1.0)
-    
-    ctx.restore()
-
-    ctx.set_operator(cairo.OPERATOR_OUT_REVERSE)
-    ctx.set_source_surface (punch, 0, 0)
-    ctx.paint()
-
-    ctx.save()
+    punch_cr = cairo.Context (punch)
+    draw_3circles (punch_cr, xc, yc, radius, 1.0)
 
-    ctx.set_target_surface(circles)
-    ctx.set_operator(cairo.OPERATOR_OVER)
-    draw_3circles(ctx, xc, yc, radius, 0.5)
-    
-    ctx.restore()
+    overlay_cr.set_operator (cairo.OPERATOR_DEST_OUT)
+    overlay_cr.set_source_surface (punch, 0, 0)
+    overlay_cr.paint()
 
-    ctx.set_operator(cairo.OPERATOR_ADD)
-    ctx.set_source_surface (circles, 0, 0)
-    ctx.paint()
+    # Now draw the 3 circles in a subgroup again
+    # at half intensity, and use OperatorAdd to join up
+    # without seams.
+    circles_cr = cairo.Context (circles)
+  
+    circles_cr.set_operator (cairo.OPERATOR_OVER)
+    draw_3circles (circles_cr, xc, yc, radius, 0.5)
 
-    ctx.restore()
+    overlay_cr.set_operator (cairo.OPERATOR_ADD)
+    overlay_cr.set_source_surface (circles, 0, 0)
+    overlay_cr.paint()
 
     ctx.set_source_surface (overlay, 0, 0)
     ctx.paint()
-
     
 def expose(drawingarea, event):
     ctx = cairo.gtk.create_cairo_context(drawingarea.window)
@@ -141,7 +110,6 @@
                                          
     return False
 
-
 def main():
     win = gtk.Window()
     win.connect('destroy', gtk.main_quit)