Hi Abhinav,You have found some unexpected behavior in pygame.surfarrray. blit_array is improperly named. It is a straight copy, not a true blit. And when a 3d array is copied to a 32 bit source alpha surface the per-pixel alpha is 0. The destination surface is completely transparent. The only workaround I can find is to set alpha to 255 after the blit_array() call:
r_mysurface = storeObject.lib_get(o_id,"__render_surface")
pygame.surfarray.blit_array(r_mysurface, r_myarray)
pygame.surfarray.pixels_alpha(r_mysurface)[...] = 255
In Pgame 1.9 this will also work:
r_mysurface.fill((0,0,0,255), None, pgyame.BLIT_RGBA_MAX)
I don't know if the 0 alpha is a bug or simply a peculiarity. Elsewhere
in Pygame a 3-element color has an alpha of 255. But blit_array has
probably set alpha to 0 since it was first implemented. It has simply
gone unnoticed until now. Should it be changed?
Lenard Abhinav Lele wrote:
Hi,
I am using surfarray to blit an image.
When i use array2d i see the image being renderer, but with array3d i dont.
I use the following code to load image :
r_temp_surface = pygame.image.load(fpath).convert_alpha()
salpha = r_temp_surface.get_alpha()
r_surface = pygame.Surface((o_w,o_h)).convert_alpha()
pygame.transform.smoothscale(r_temp_surface,(o_w,o_h),r_surface)
#if salpha != None:
# r_surface.set_alpha(salpha)
r_array = pygame.surfarray.array3d(r_surface)
print "New Surface Alpha: " , r_surface.get_alpha()
storeObject.lib_set(o_id,"__render_surface",r_surface)
storeObject.lib_set(o_id,"__render_array",r_array)
To render I use :
r_myarray = storeObject.lib_get(o_id,"__render_array")
r_mysurface = storeObject.lib_get(o_id,"__render_surface")
pygame.surfarray.blit_array(r_mysurface, r_myarray)
surface.blit (r_mysurface,(gx,gy))
Plz help.
-Abhinav
-- Lenard Lindstrom <len-l@xxxxxxxxx>