zoom - Scale Transformation Function #

Scale transformation from center point

Syntax #

(zoom factor)           ; Scale from screen center
(zoom factor x y)       ; Scale from custom center point

Parameters #

• factor: Scale multiplier (>1 = zoom in, <1 = zoom out)
• x, y: Center point for scaling (optional, defaults to screen center)

Behavior #

• Scales all pixels toward or away from the center point
• Uses accumulation system for smooth continuous zooming
• Maintains aspect ratio and pixel relationships
• Values above 1.0 zoom in, below 1.0 zoom out

Examples #

Basic Scaling #

(zoom 1.1)         ; Gradual zoom in
(zoom 0.9)         ; Gradual zoom out
(zoom 2.0)         ; 2x magnification

Custom Center Point #

(zoom 1.5 100 100)    ; Zoom into point (100,100)
(zoom 0.8 width height) ; Zoom out from bottom-right

Animation Sequences #

(s0.1 (zoom 1.01))    ; Slow continuous zoom
["3s..." 1.1 0.9]     ; Alternating zoom in/out

Combined Transformations #

(zoom 1.05)        ; Scale slightly
(spin 0.5)         ; Add rotation
(scroll 1 0)       ; Add movement

Implementation Notes #

• Accumulation threshold prevents excessive computation
• Bicubic interpolation for smooth results
• Compatible with embedded layer system
• Efficient real-time performance

Related Functions #

• scroll - Translation transformation
• spin - Rotation transformation
• suck - Radial displacement transformation