ShapeTwiddle.mesa
Last Edited by: Crow, September 30, 1987 6:43:45 pm PDT
DIRECTORY
Rope USING [ ROPE ],
ThreeDBasics USING [ Context, ShapeInstance ];
Types
Context: TYPE ~ ThreeDBasics.Context;
ShapeInstance: TYPE ~ ThreeDBasics.ShapeInstance;
ShapeTwiddleError: SIGNAL [reason: ATOM];
NatPair: TYPE ~ RECORD [x, y: NAT];
Shape Manipulations
ScaleShape:
PROCEDURE [context:
REF Context, name: Rope.
ROPE,
scale, xRatio, yRatio, zRatio:
REAL ← 1.0,
applyXfm:
BOOLEAN ←
FALSE];
Scale vertices, global scale is scaled by ratio for each axis. Transform vertices to current
position before scaling. New vertices will be the transformed and scaled result. Position transform is reset to identity.
ScaleTexture:
PROCEDURE [ context:
REF Context, name: Rope.
ROPE,
scale, xRatio, yRatio, zRatio:
REAL ← 1.0];
Scales texture coordinates of vertices. xRatio, etc. can be used to set scale assymetrically.
eg. texture.x ← texture.x * scale * xRatio.
Accumulated scale factor is stored on shape shadingProps list ($TextureScale).
CleanUp:
PROC [context:
REF Context, name: Rope.
ROPE,
deSeam:
BOOLEAN ←
FALSE, tolerance:
REAL ← 0.0];
Throw out unused vertices. If deseaming, then coalesce vertices no more than "tolerance" apart. If deseaming polygons, eliminate redundant vertex pointers.
CopyShape:
PROC [context:
REF Context, dstName, srcName: Rope.
ROPE]
RETURNS[
REF ShapeInstance];
Copy shape so that the copy may be abused by the other routines herein whil maintaining the original intact.
Combine:
PROC [context:
REF Context, dstName, src1, src2: Rope.
ROPE]
RETURNS[
REF ShapeInstance];
Combine two objects, producing a new object with all the vertices and patches of both.
DeletePatches:
PROC [context:
REF Context, dstName, srcName: Rope.
ROPE,
patchList:
LIST
OF NatPair]
RETURNS[
REF ShapeInstance];
Produce a new object without the listed intervals of patches. Good for disassembling objects. Use "CleanUp" afterwards, since all vertices are copied to the new object.
Bounds:
PROC [context:
REF Context, name: Rope.
ROPE]
RETURNS[xMin, xMax, yMin, yMax, zMin, zMax:
REAL];
Find the bounding box of the vertices after applying the position transform.