pgBitBlt

JJPeerless · Post by **JJPeerless** » Thu Jun 23, 2005 8:13 am

using pgBitBlt, is it possible to BitBlt to something other than the "screen"..does the psp only have one screen buffer? or can i have like a Graphics object to draw to..then blit that to the screen buffer and then flip that..

i want to be able to blit to other surfaces before flipping them to the screen..

inomine · Post by **inomine** » Thu Jun 23, 2005 8:19 am

Have a look at the "Unlimited sin ball" demo from AloneTrio, the source is pretty straight forward to understand. It does what you are looking for, for a maximum of 7 buffers.

If you don't understand it after looking at it for a while come back and we'll take it from there.

JJPeerless · Post by **JJPeerless** » Thu Jun 23, 2005 8:25 am

if you wouldnt mind me asking, where do i get this demo?

JJPeerless · Post by **JJPeerless** » Thu Jun 23, 2005 8:28 am

just found it, nevermind

JJPeerless · Post by **JJPeerless** » Thu Jun 23, 2005 8:31 am

dont really get it tho..

pgScreenFrame

does it have to do with that?

JJPeerless · Post by **JJPeerless** » Thu Jun 23, 2005 8:34 am

all i really wanna be able to do is.. blit to a second buffer... then clip that so its the size of the screen 480x272..and then flip that to the screen..

thats all..

inomine · Post by **inomine** » Thu Jun 23, 2005 8:40 am

Right, it's as simple as this.

The PSP has 2Mb of VRAM, this is what the nice pointer that you have is pointing to the top of. Obviously 272 lines at 512 pixels does not use all of it, so all you have to do to get a new framebuffer is write further down in the RAM than the end of the screen of the current buffer. Then all you do is call

Code: Select all

pspDisplaySetFrameBuf&#40;pg_vramtop,512,1,1&#41;;

to set the screen to be displayed from the pointer pg_vramtop.

Hmm, not really the best explanation ever but have a read of his code along with these comments.

JJPeerless · Post by **JJPeerless** » Thu Jun 23, 2005 8:48 am

im using Nem's PG library to do all my graphics stuff..
i dont really understand what you are trying to say..

do i have to edit nem's pg stuff..because his pgbitblt function only blits to the top buffer?

is that it?

inomine · Post by **inomine** » Thu Jun 23, 2005 8:52 am

Nem's stuff is nice but if you want to get anywhere I would say ditch it and make your own, that way you will actually understand what is happening a lot better.

JJPeerless · Post by **JJPeerless** » Thu Jun 23, 2005 8:53 am

i totally agree..because i dont know how nem's stuff works..i only know how to use it..

where can i learn about the psp's functions he used to do what he did..

jboldiga · Post by **jboldiga** » Thu Jun 23, 2005 8:56 am

You can also point to another area in vram like inomine said and use that as a texture. Rendering to a texture can produce some nice effects. As for how to get started on psp, you might want to look at how things work on PS2 since its heavily documented and would give a firm grasp of the architecture before diving into psp dev. There are a bunch of api lib calls here on the forums.

inomine · Post by **inomine** » Thu Jun 23, 2005 8:57 am

JJPeerless wrote: where can i learn about the psp's functions he used to do what he did..

Read his code, go from there. Have a play with some of the functions in the lib and maybe try to add some of your own.