iOS Developer – Canvas Size & DPI Fix (Metal / Core Graphics Expert) -- 2
Budget: $30 – $70 USD
We need an experienced iOS developer to fix a critical canvas sizing issue in our professional design app, Patternata. The app is used by designers to create textile patterns for printing, so accurate physical dimensions and DPI handling are very important.
The main problem is that the canvas is not rendering at its true physical size and resolution. For example, a 70 by 70 cm canvas at 300 DPI should display as 8268 by 8268 pixels, but right now it only renders at around 500 by 500 pixels. This prevents designers from seeing accurate detail during creation and also causes incorrect exports.
Your task will be:
• Fix the canvas sizing system so that it reflects true physical dimensions at 300 DPI
• Ensure the fix works consistently across both display and export
• Verify the accuracy of the output with test cases such as 70 by 70 cm and 70 by 180 cm canvases
Requirements for this project include:
• At least five years of iOS development experience using Swift and UIKit
• Strong expertise in Metal, Core Graphics, and tiled rendering
• Solid understanding of DPI management and professional printing standards
• Experience with graphics-heavy apps such as drawing or canvas-based software
• Familiarity with Apple Pencil and PencilKit is a plus
The codebase is clean and well-structured, so you can focus directly on solving this issue without being distracted by unrelated features. This is a fixed-price project, and we will discuss the budget and timeline with you. If you have worked on similar problems in graphics-heavy iOS apps, please share examples of your work.
The main problem is that the canvas is not rendering at its true physical size and resolution. For example, a 70 by 70 cm canvas at 300 DPI should display as 8268 by 8268 pixels, but right now it only renders at around 500 by 500 pixels. This prevents designers from seeing accurate detail during creation and also causes incorrect exports.
Your task will be:
• Fix the canvas sizing system so that it reflects true physical dimensions at 300 DPI
• Ensure the fix works consistently across both display and export
• Verify the accuracy of the output with test cases such as 70 by 70 cm and 70 by 180 cm canvases
Requirements for this project include:
• At least five years of iOS development experience using Swift and UIKit
• Strong expertise in Metal, Core Graphics, and tiled rendering
• Solid understanding of DPI management and professional printing standards
• Experience with graphics-heavy apps such as drawing or canvas-based software
• Familiarity with Apple Pencil and PencilKit is a plus
The codebase is clean and well-structured, so you can focus directly on solving this issue without being distracted by unrelated features. This is a fixed-price project, and we will discuss the budget and timeline with you. If you have worked on similar problems in graphics-heavy iOS apps, please share examples of your work.