Implement remaining SVG filter primitives/CSS filter functions #1296
Description
Location: sparse_strips/vello_common/src/filter_effects.rs
Context: Initial filter effects implementation in #1286
The following filter primitives are defined in the FilterPrimitive enum. Currently only 3 are implemented:
- Flood - Generate a solid color fill (typically used as input to other filter operations)
- GaussianBlur - Gaussian blur using specified standard deviation
- DropShadow - Drop shadow effect (compound primitive combining blur, offset, and compositing)
- ColorMatrix - Matrix-based color transformations (4x5 matrix for arbitrary color space transformations, hue shifts, and color adjustments)
- Offset - Geometric offset/translation (shifts input by dx, dy)
- Composite - Porter-Duff compositing operations (over, in, out, atop, xor)
- Blend - Photoshop-style blend modes (multiply, screen, overlay, etc.)
- Morphology - Morphological operations (dilate/erode) for expanding or contracting shapes
- ConvolveMatrix - Custom convolution kernels for sharpening, edge detection, embossing, and custom filters
- Turbulence - Generate Perlin noise/turbulence patterns for textures, clouds, and organic randomness
- DisplacementMap - Displace pixels using a displacement map for warping and distortion effects
- ComponentTransfer - Per-channel transfer functions using lookup tables (for color corrections, gamma adjustments, and custom mappings)
- Image - Reference external images as filter input from resource atlas
- Tile - Tile the input to fill the filter region with repeating patterns
- DiffuseLighting - Diffuse lighting simulation treating alpha channel as height map
- SpecularLighting - Specular lighting simulation for shiny reflection highlights
The following filter functions (CSS-style shorthand filters) are defined in the FilterFunction enum. Currently only 1 is implemented:
- Blur - Gaussian blur effect
- Brightness - Brightness adjustment (linear multiplier)
- Contrast - Contrast adjustment
- Grayscale - Grayscale conversion with adjustable strength
- HueRotate - Hue rotation by specified angle in degrees
- Invert - Color inversion
- Opacity - Opacity adjustment (multiplies alpha channel)
- Saturate - Saturation adjustment
- Sepia - Sepia tone effect (vintage/old photo appearance)