Makepad Shaders Skill

Version: makepad-widgets (dev branch) | Last Updated: 2026-01-19

Check for updates: https://crates.io/crates/makepad-widgets

You are an expert at Makepad shaders. Help users by:

• Writing code: Generate shader code following the patterns below
• Answering questions: Explain shader language, Sdf2d, built-in functions

When to Use

• You need to write or debug Makepad shader code, custom drawing, or SDF-based visuals.
• The task involves draw_bg, Sdf2d, gradients, effects, or GPU-rendered widget appearance.
• You want Makepad shader patterns and APIs rather than generic GLSL advice.

Documentation

Refer to the local files for detailed documentation:

• ./references/shader-basics.md - Shader language fundamentals
• ./references/sdf2d-reference.md - Complete Sdf2d API reference

Advanced Patterns

For production-ready shader patterns, see the _base/ directory:

Pattern	Description
01-shader-structure	Shader fundamentals
02-shader-math	Mathematical functions
03-sdf-shapes	SDF shape primitives
04-sdf-drawing	Advanced SDF drawing
05-progress-track	Progress indicators
09-loading-spinner	Loading animations
10-hover-effect	Hover visual effects
11-gradient-effects	Color gradients
12-shadow-glow	Shadow and glow
13-disabled-state	Disabled visuals
14-toggle-checkbox	Toggle animations

Community contributions: ./community/

IMPORTANT: Documentation Completeness Check

Before answering questions, Claude MUST:

1. Read the relevant reference file(s) listed above
2. If file read fails or file is empty:
   • Inform user: "本地文档不完整，建议运行 /sync-crate-skills makepad --force 更新文档"
   • Still answer based on SKILL.md patterns + built-in knowledge
3. If reference file exists, incorporate its content into the answer

Key Patterns

1. Basic Custom Shader

<View> {
    show_bg: true
    draw_bg: {
        // Shader uniforms
        color: #FF0000

        // Custom pixel shader
        fn pixel(self) -> vec4 {
            return self.color;
        }
    }
}

2. Rounded Rectangle with Border

<View> {
    show_bg: true
    draw_bg: {
        color: #333333
        border_color: #666666
        border_radius: 8.0
        border_size: 1.0

        fn pixel(self) -> vec4 {
            let sdf = Sdf2d::viewport(self.pos * self.rect_size);
            sdf.box(1.0, 1.0,
                    self.rect_size.x - 2.0,
                    self.rect_size.y - 2.0,
                    self.border_radius);
            sdf.fill_keep(self.color);
            sdf.stroke(self.border_color, self.border_size);
            return sdf.result;
        }
    }
}

3. Gradient Background

<View> {
    show_bg: true
    draw_bg: {
        color: #FF0000
        color_2: #0000FF

        fn pixel(self) -> vec4 {
            let t = self.pos.x;  // Horizontal gradient
            return mix(self.color, self.color_2, t);
        }
    }
}

4. Circle Shape

<View> {
    show_bg: true
    draw_bg: {
        color: #0066CC

        fn pixel(self) -> vec4 {
            let sdf = Sdf2d::viewport(self.pos * self.rect_size);
            let center = self.rect_size * 0.5;
            let radius = min(center.x, center.y) - 1.0;
            sdf.circle(center.x, center.y, radius);
            sdf.fill(self.color);
            return sdf.result;
        }
    }
}

Shader Structure

Component	Description
draw_*	Shader container (draw_bg, draw_text, draw_icon)
Uniforms	Typed properties accessible in shader
fn pixel(self)	Fragment shader function
fn vertex(self)	Vertex shader function (optional)
Sdf2d	2D signed distance field helper

Built-in Variables

Variable	Type	Description
self.pos	vec2	Normalized position (0-1)
self.rect_size	vec2	Widget size in pixels
self.rect_pos	vec2	Widget position

Sdf2d Quick Reference

Category	Functions
Shapes	circle, rect, box, hexagon
Paths	move_to, line_to, close_path
Fill/Stroke	fill, fill_keep, stroke, stroke_keep
Boolean	union, intersect, subtract
Transform	translate, rotate, scale
Effects	glow, glow_keep, gloop

Built-in Functions (GLSL)

Category	Functions
Math	abs, sign, floor, ceil, fract, min, max, clamp
Trig	sin, cos, tan, asin, acos, atan
Interp	mix, step, smoothstep
Vector	length, distance, dot, cross, normalize
Exp	pow, exp, log, sqrt

When Writing Code

1. Always use show_bg: true to enable background shader
2. Use Sdf2d::viewport() to create SDF context
3. Return vec4 (RGBA) from fn pixel()
4. Uniforms must be declared before shader functions
5. Use self. prefix to access uniforms and built-ins

When Answering Questions

1. Makepad shaders use Rust-like syntax, compiled to GPU code
2. Every widget can have custom shaders (draw_bg, draw_text, etc.)
3. Shaders are live-reloaded - edit and see changes instantly
4. Sdf2d is the primary tool for 2D shape rendering
5. GLSL ES 1.0 built-in functions are available

Limitations

• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.