Search found 37 matches

by peekpoke
Thu Feb 21, 2013 9:08 pm
Forum: Megadrive/Genesis
Topic: Genny and 3D
Replies: 138
Views: 99188

Thx! Tried this method right now. Seems that there is some problems with pointers in gcc 3.4.6 (included in GenesisDev04), so - quick copypaste+adaptation (changed my "blit" routine to draw from new screenbuffer to tilebuffer first, also removed double pixel addition for test) didnt worked at first....
by peekpoke
Thu Feb 21, 2013 6:32 am
Forum: Megadrive/Genesis
Topic: Genny and 3D
Replies: 138
Views: 99188

Thank you very much! To be true, i didnt get rid of that divide fully. Im really very noob in programming, just read somewhere that div is much slower (few times maybe?) than mul, so here was the first idea of "optimising" this divide - i just changed it on mul by precalc lut for 4096/sliceHeight :r...
by peekpoke
Mon Feb 18, 2013 5:48 pm
Forum: Megadrive/Genesis
Topic: Genny and 3D
Replies: 138
Views: 99188

I tried to port Jeremy A Burns' LCD Raycaster Just changed sine/cosine, square root calculations to precalc lookup tables. Also created lut for bitmap2tile coords translation. Changed everything to integer math. Also changed few constants, which used in calulations to pow 2 aligned, so instead of us...
by peekpoke
Sun Feb 03, 2013 4:13 pm
Forum: Video Display Processor
Topic: How to propertly scroll wide image?
Replies: 11
Views: 7690

Thank you, Chilly Willy - readed about volatile variables, also refreshed knowledge on clearing/setting bits, so may now propertly disable/enable vblank int, when needed. But in meantime tried to implement "edge only" method, thx to djcouchycouch and Gigasoft for pointing on it. I just load tiles in...
by peekpoke
Fri Feb 01, 2013 8:31 pm
Forum: Video Display Processor
Topic: How to propertly scroll wide image?
Replies: 11
Views: 7690

Thank you very much! Did those quick changes. Removed setting of horizontal scroll from main loop (at joy check - also now it not check if swap is set). Left there only scroll variable increment. Added VDP_waitVSync() in the end of main loop. Now each vblank horizontal scroll is setted up. And if sw...
by peekpoke
Fri Feb 01, 2013 7:36 pm
Forum: Video Display Processor
Topic: How to propertly scroll wide image?
Replies: 11
Views: 7690

Chilly Willy , Gigasoft , djcouchycouch , thank you very much for answering! Chilly Willy , tried to implement ur solution first. I set plan to 128x32 size, then "drawed" first 41x28 chunk of picture at left side of plan. Then started scrolling plan from left to right by 1px. When scrolled 8px, vbl...
by peekpoke
Fri Feb 01, 2013 2:32 am
Forum: Video Display Processor
Topic: How to propertly scroll wide image?
Replies: 11
Views: 7690

How to propertly scroll wide image?

Hi, all! Im total newbie in programming. But very want to start learning. Sega Megadrive is a console from my childhood - so, i decded, why not combine those two things. Already did simple hello world (Conway's Game of Life demo). Now want to understand how to scroll some wide background picture. Bu...