feat: Add ShaderToy conversion tools

Add automated conversion pipeline for ShaderToy shaders to demo effects:
- convert_shadertoy.py: Automated code generation script
- Manual templates: Header, implementation, and WGSL boilerplate
- Example shader: Test case for conversion workflow
- README: Complete conversion guide with examples

Handles basic GLSL→WGSL conversion (types, uniforms, mainImage extraction).
Manual fixes needed for fragColor returns and complex type inference.

Organized under tools/shadertoy/ for maintainability.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/tools/shadertoy/example.txt b/tools/shadertoy/example.txt
new file mode 100644
index 0000000..e0287de
--- /dev/null
+++ b/tools/shadertoy/example.txt
@@ -0,0 +1,25 @@
+// Example ShaderToy shader for testing convert_shadertoy.py
+// Simple animated gradient effect
+//
+// Test with:
+//   ./tools/shadertoy/convert_shadertoy.py tools/shadertoy/example.txt Rainbow
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord) {
+    // Normalized pixel coordinates (from 0 to 1)
+    vec2 uv = fragCoord / iResolution.xy;
+
+    // Center coordinates
+    vec2 center = uv - 0.5;
+
+    // Distance from center
+    float dist = length(center);
+
+    // Animated rainbow colors
+    vec3 col = 0.5 + 0.5 * cos(iTime + dist * 10.0 + vec3(0.0, 2.0, 4.0));
+
+    // Pulsing effect
+    col *= 1.0 + 0.2 * sin(iTime * 2.0);
+
+    // Output to screen
+    fragColor = vec4(col, 1.0);
+}