glycorender

A bespoke SVG to PDF/PNG renderer for the GlycoDraw platform, specialized in accurately rendering glycan structures with support for chemical notations and path-based text positioning.

Features

• Accurate SVG to PDF and PNG conversion for glycan structures
• Support for text on paths with proper positioning and orientation
• Special handling for monosaccharide properties like "Df" with proper styling
• Gradient fills for circles and shapes
• Precise connection path rendering between glycan elements
• Support for various SVG path commands

Installation

pip install glycorender

Quick Start

from glycorender import convert_svg_to_pdf, convert_svg_to_png

# Convert SVG file to PDF
with open('glycan_structure.svg', 'r') as f:
    svg_data = f.read()
    
convert_svg_to_pdf(svg_data, 'output.pdf')

# Convert SVG file to PNG
convert_svg_to_png(svg_data, 'output.png')

# Or directly from SVG data
svg_data = """..."""
convert_svg_to_pdf(svg_data, 'output.pdf')
convert_svg_to_png(svg_data, 'output.png')

Use Cases

GlycoRender is specifically designed for:

• Converting glycan structure diagrams from GlycoDraw to publication-quality PDFs or PNGs
• Preserving the exact layout and styling of complex carbohydrate representations
• Ensuring chemical notations are properly formatted in the output
• Maintaining the correct connections between monosaccharide units

API Reference

convert_svg_to_pdf(svg_data, pdf_file_path, return_canvas=False, chem=False, shadow=False, sticker=False)

Renders SVG data to a PDF with embedded, subset fonts.

convert_svg_to_png(svg_data, png_file_path=None, output_width=None, output_height=None, scale=None, return_bytes=False, chem=False, background=None, shadow=False, sticker=False)

Renders SVG data to a PNG. scale multiplies the page size (1.0 is 72 dpi, 300 / 72 is 300 dpi), and the resolution is stored in the file, so the PNG is placed at the same physical size as the PDF. background=None keeps the background transparent.

Parameters shared by both:

• svg_data (str or bytes): SVG content
• shadow (bool or dict): soft drop shadow under the monosaccharide symbols; a dict overrides dx, dy, blur, alpha, color
• sticker (bool or dict): die-cut outline around the whole structure; a dict overrides width, color, edge, edge_color, shadow
• chem (bool): the input is an RDKit SVG

pdf_to_svg_bytes(svg_string, shadow=False, sticker=False)

Returns an SVG that looks exactly like the PDF, with text as outlines.

simple_svg_to_pdf(svg_data, pdf_path) / simple_svg_to_png(svg_data, png_path)

Render a general matplotlib-style SVG (e.g., a figure with embedded glycans) without glycan-specific handling.

Supported SVG Elements

• <path>: Full support for path commands (M, L, H, V, Z, etc.)
• <circle>: Support for basic circles and gradient-filled circles
• <rect>: Support for rectangles with stroke and fill
• <text> and <textPath>: Support for text placement along paths with proper orientation
• <defs>: Support for path and gradient definitions
• <radialGradient>: Support for radial gradients with stops

Dependencies

• numpy

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.