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https://github.com/bhouston/2dbumpmapdemo1996

Real-Time 2D Bump Mapping for 16 DOS, Demo Scene 1996 https://files.scene.org/view/mirrors/hornet/code/effects/bump/azr_bump.zip
https://github.com/bhouston/2dbumpmapdemo1996

computer-graphics demoscene dos

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Real-Time 2D Bump Mapping for 16 DOS, Demo Scene 1996 https://files.scene.org/view/mirrors/hornet/code/effects/bump/azr_bump.zip

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README 

        

# Experiments in 2D Phong Bump-Mapping



Ben Houston / PLaSH of AzurE

E-Mail: [email protected]



Friday, August 30, 1996 (Ottawa Release)

Friday, November 22, 1996 (Internet Release)



## Overview



Sometime back in July I downloaded a source and doc written by a

member of the french demo group Flower Corp showing an example of

bump-mapping.  The algorithm for the 2d bump-mapping was interesting

but fairly slow on my 486 computer.  I attempted a few improvements

and the sources 'slowbump.cpp', 'fastbump.cpp' and 'bestbump.cpp' are

the result.  I'm not going to explain directly the different

techniques of how to bump-map 2D surfaces but you should be able to

decipher by sources.  If you want a document albeit in french on the

technique used in 'slowbump.cpp' you can download Flower Corp's

archive called 'flcbump.zip'.



The bump-mapping inner loop used in the first example source

'slowbump.cpp' is almost a exact rip from Flower Corps example source. 

I don't mean offence to Flower Corp by the source's name it's just

what I called it many months ago.  The only changes I made to the look

of the bump-map was the addition of a phong palette (the Flower Corp

demo use a linear palette).  The slowness of this example is causes by

the need for a multiply per lighted pixel.



The first improvement in the actual algorithm is seen in

'fastbump.cpp'.  Here I replace the simple multiply per lighted pixel

algorithm with a technique of wrapping a bitmap on the bumpy surface. 

I calculate the bitmap to contains a circular (although not in the

least correct) highlight.



The second major improvement changes the format of the run-time

surface data from pixel heights to height deltas between pixels.  This

causes the surface to double in memory usage but reduces the run-time

calculations tremendously.  The major drawback of this implementation

is that the animation that is used in the second part of

'fastbump.cpp' is not longer so easy.



The frame rate that these demos achieved on my computer was 5 fps

for 'slowbump.cpp', 8 fps (6 fps with animation) for 'fastbump.cpp',

and 16 fps for 'bestbump.cpp'.  I hope you can benefit in some way

from the three sources or at least enjoy the bump-mapping examples. 

Just remember not to rip and give credit.  I like to thank first of

all Flower Corp for releasing there bump-mapping information, Rex

Deathstar for his wonderful examples of inline assembly coding, and

everyone else who releases their old code for others to learn from. 

Feel free to e-mail me for any reason at all.  Greets to by buds

Mundane and Asch of Azure, Omega and the rest of Intra, Grimace of

Miracle, Cyclone and the rest from NAID'96.



## Contents



* SLOWBUMP.CPP, source of a bump-mapping algorithm

* FASTBUMP.CPP, source of a bump-mapping algorithm

* BESTBUMP.CPP, source of a bump-mapping algorithm

* BUMPMAP.DAT, a common data file used by all executables