Difference between revisions of "Precise Shadowcasting in JavaScript"
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### Determine the corresponding arc <code>[a1,a2]</code> | ### Determine the corresponding arc <code>[a1,a2]</code> | ||
### Consult the shadow queue to determine whether <code>[a1,a2]</code> is fully shadowed | ### Consult the shadow queue to determine whether <code>[a1,a2]</code> is fully shadowed | ||
### If no part of <code>[a1,a2]</code> is visible, mark the cell as | ### If no part of <code>[a1,a2]</code> is visible, mark the cell as '''not visible''' and advance to next cell | ||
### If some part of <code>[a1,a2]</code> is visible, merge it into the shadow queue; mark the cell as visible | ### If some part of <code>[a1,a2]</code> is visible, merge it into the shadow queue; mark the cell as '''visible''' | ||
== Tweaks, tricks and advanced topics == | == Tweaks, tricks and advanced topics == | ||
Revision as of 15:26, 3 January 2013
This pages describes and explains the Precise Shadowcasting algorithm, developed and implemented by Ondřej Žára in rot.js.
WORK IN PROGRESS
About
General algorithm workflow
- Let
[x,y]be the player coordinates - Initialize the empty shadow queue
- For
R=1up to maximum visibility range do:- Retrieve all cells whose range from
[x,y]isR - Make sure these cells are in correct order (clockwise or counter-clockwise; every iteration starting at the same angle)
- For every cell in this "ring":
- Determine the corresponding arc
[a1,a2] - Consult the shadow queue to determine whether
[a1,a2]is fully shadowed - If no part of
[a1,a2]is visible, mark the cell as not visible and advance to next cell - If some part of
[a1,a2]is visible, merge it into the shadow queue; mark the cell as visible
- Determine the corresponding arc
- Retrieve all cells whose range from