Thread View: rec.games.programmer
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Started by Roger Uzun
Thu, 06 Sep 1990 22:36
Re: Animation Speed & Redraw
Author: Roger Uzun
Date: Thu, 06 Sep 1990 22:36
Date: Thu, 06 Sep 1990 22:36
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>>Dallas Hodgson wrote: No need for a 3rd bitmap what I was referring to was
>>display screen A while clearing out B, then drawing objects into B,
>>if you have a large background then you can replace clearing out
>>B with copying background into B.
That is what a 3rd bitmap is used for! to be a "clean" copy of the
background. Most modern games have very detailed backgrounds, and
the method you proposed does call for a 3rd bitmap to be maintained,
the 3rd bitmap is of a clean background, and is never displayed.
Most all developers on the amiga, who develop for the amiga, make
use of hardware sprites, they are hardly a headache at all, while
not a complete solution, for most games they take much of the
load off the processor blitter, 64 pixel width of 16 color object
per scanline is not trivial, neither is 128 pixel width of 4 color
object (well really 3 and 15 colors but..) The one scanline gap
between objects is not a big problem in most cases since sprites can
be ANY height.
Blood Money uses mostly all sprites.
Heart of the Dragon makes extensive use of sprites hardware.
With the older agnus, I think you cannot blit a 320X200X4 bit screen
is a single pass, but I forget for sure.
I have never tried the blast out the background technique (using the
3rd off screen bitmap) on the amiga, but I have on the Apple //, Apple
Macintosh II (8 bit video), and Atari computers. It was a total
disaster on the Mac II, the processor could easily animate many
rectangular objects with shadow masks for cookie-cutter like
effects, and copying in the background each time just killed
performance, you got like 8 frames/sec using the 3rd bitmap approach.
Of course this was a 640X480X8 bit screen. Still in my experience with
the Amiga, I do not feel that blitting in the entire background would
be as fast, or even nearly so, as using sprites and/or raster objects
with shadow masks.
Maybe I will do a benchmark and see how it is, for now all I can say
is my feeling is that the 3 bitmap approach will be slower.
-Roger
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Re: Animation Speed & Redraw
Author: Peter da Silva
Date: Sat, 08 Sep 1990 02:51
Date: Sat, 08 Sep 1990 02:51
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Has anyone else had a look at Steve B. Speier's "VASS" system? It gives you 16-color virtual sprites... -- Peter da Silva. `-_-' <peter@sugar.hackercorp.com>.
Re: Animation Speed & Redraw
Author: Michel Buffa
Date: Sat, 08 Sep 1990 07:07
Date: Sat, 08 Sep 1990 07:07
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In article <4275@crash.cts.com>, uzun@pnet01.cts.com (Roger Uzun) writes: > > Most all developers on the amiga, who develop for the amiga, make > use of hardware sprites FALSE. Look at most of the arcade games on the amiga. Each object is more than 4 colors (or even 16 in some of them). Only games like datastorm use hardware sprites. Battle squadron doesn't use sprites. Silkworm doesn't use sprites (The object are too numerous and too long to be sprites, Turrican doesn't use sprites: same method as the one used in blood money, see explanations later) > Blood Money uses mostly all sprites. FALSE ! I read a bunch of article in THE ONE (an english magasine), all written by the author of blood money, and he said that there was NO SPRITE at all in blood money. Only Blitter Objects. I recommend reading this magazine: it contains each month some technical articles written by an author of some famous games. During six months they gave almost the entire code of Menace, with full explanations. > With the older agnus, I think you cannot blit a 320X200X4 bit screen > is a single pass, but I forget for sure. Why do you want to do it in a single pass. The blitter is fast enough to do several operations during each vbl (60 times/second) in blood money, the following technique is used (read in the magazine) the scrolling uses both the blitter and the copper. The copper is used to scroll one line every 1/50s, and every 50/16s, the blitter is used to map only a row or a column, with 16x16 basic squares of background. Before pasting an object on the scroll, the followings steps are achieved: -restore previous portions of background (where the objects were in the previous frame) -calculate new positions of the objects, test collisions -save what will be behind the object you are going to paste in the current frame. (a special "save buffer" is associated to each object) -paste the new objects on the background Everything is done with the blitter and the copper (the copper avoids to redraw the full background evry frame, so the blitter is used only to animate the objects, and each 16 frames to map a row or a column in the scrolling background. >
Re: Animation Speed & Redraw
Author: Simon Raybould
Date: Mon, 10 Sep 1990 15:15
Date: Mon, 10 Sep 1990 15:15
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In article <1990Sep7.094337@sardaigne.inria.fr> buffa@mirsa.inria.fr writes: >FALSE ! I read a bunch of article in THE ONE (an english magasine), all >written by the author of blood money, and he said that there was NO SPRITE at >all in blood money. Only Blitter Objects. I recommend reading this magazine: >it contains each month some technical articles written by an author of some >famous games. During six months they gave almost the entire code of Menace, >with full explanations. The menace source code was actually in 'Amiga Format' not 'The One'. I have a subscription with Amiga Format and have all of the Menace source. Only the Source for the first level was released, there was no need for more, it shows animation, sound and end of level Guardian. For anyone who's interested, the series was titled 'The whole truth about games programing' and was written by Dave Jones. Cheers SJR
Re: Animation Speed & Redraw
Author: Simon Raybould
Date: Mon, 10 Sep 1990 15:15
Date: Mon, 10 Sep 1990 15:15
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In article <1990Sep7.094337@sardaigne.inria.fr> buffa@mirsa.inria.fr writes: >FALSE ! I read a bunch of article in THE ONE (an english magasine), all >written by the author of blood money, and he said that there was NO SPRITE at >all in blood money. Only Blitter Objects. I recommend reading this magazine: >it contains each month some technical articles written by an author of some >famous games. During six months they gave almost the entire code of Menace, >with full explanations. The menace source code was actually in 'Amiga Format' not 'The One'. I have a subscription with Amiga Format and have all of the Menace source. Only the Source for the first level was released, there was no need for more, it shows animation, sound and end of level Guardian. For anyone who's interested, the ceries was titled 'The whole truth about games programing' and was written by Dave Jones. Cheers SJR
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