Printable View
Anyone?
I coded my own ASM MS-DOS picture routine, which uses 32bit
instruction codes to transfer pics onto, say a 800x600x16 screen,
on my old SiS 5597 chip, the FPS is around 15. Later I use DirectX
to do the same, and it goes around 100 over.
This is due to Windows hardware acceleration function, besides
asking the driver to accelerate the hardware...
So, anyone know of the instruction codes to accelerate VGA chips?
Every graphics card has it's own set of instruction to make use of hardware acceleration. These are very hard to obtain, have no ASM equivalent (must be directly coded in hex) and undocumented. Some companies, like ATI, will give you info on them if you beg and grovel enough. Others, like nVidia, don't, and you have to use their drivers to use hardware acceleration, and if you happen to have an OS for which no drivers exist (i.e. any UNIX version) - well, bad luck.
There is a project going on, they want to write drivers that give 3d acceleration to the linux implementation of OpenGL, they have info about ATI cards, but not about nVidia cards, so they can't support those. nVidia doesn't write any drivers for linux. From their point of view it's a waste of resources, 99% of the people that need acceleration use windows.)
But 15 FPS seems quite slow to me, I'm sure you could do better.
15 FPS...
I wrote the cleanest asm code ever to achieve this:
I STOSD to it and use Bank switching.
BTW, about the gfx acceleration function, I didn't mean DirectX
or the display driver. If you goto My Computer -> Properties ->
Performance -> Graphics
u'll see that Hardware Acceleration
That would be hardware blitting support then. Still something that must be supported by the card, and you have to know how to access it for each card.
Well, not really, as far as I'm concerned.
If u use the standard VGA driver provided by Windows(which
gives u only 640x480x4bits), u still have that vga hardware
acceleration.
And wut is this hardware blitting?
is it like when u draw a picture that is off the screen?
Well, blitting in general is copying a rectangular image area to another image, usually the screen. Hardware blitting would be hardware support for that: the graphics card can copy data from one place in the video RAM to another faster than your code can.
Haha, really?
I know how to do it yet dont know wut it's called :p
However, to ask the hardware to do the blitting, okay, this is
impossible unless u know the right way to do it for different
cards.
So, u mentioned must be directly coded in Hex, really?
Then the CPU must've don't know how to handle it if it has no
ASM equavalent.
I thought the code would just OUT some card specific bits
and that'll do the trick.
Yeah, "that's it". Of course you first need to know those card specific bits.
Oh...*sigh*
So gotta stick to VESA...
In comparison, how much faster will the hardware driver
outperform VESA in average?
I have no idea, that depends on what you do. When blitting a few large bitmaps the hardware will waayyyyy outperform software blitting. When blitting many small bitmaps the difference will be smaller.
So does VESA have atleast a basic function to do hardware
blitting which all cards must obey? I mean a universal standard
hardware blitting function?
I don't know. I started programming about 4 years ago, so even though I know quite a lot of computer internals I don't know much about DOS programming.
O...well, i c
Anyway,thx 4 ur replies :p