stride3d/stride · error · ArgumentException

Tried to compile a dynamic sprite font with compiler for…

Error message

Tried to compile a dynamic sprite font with compiler for static fonts

What it means

OfflineRasterizedFontCompiler.Compile casts fontAsset.FontType to OfflineRasterizedSpriteFontType; if the cast returns null the asset uses a dynamic (runtime-rasterized) font type, which this static compiler cannot handle, so an ArgumentException is thrown.

Solutions

  1. Use the appropriate compiler for dynamic fonts (dynamic font factory/runtime path).
  2. Check fontAsset.FontType is OfflineRasterizedSpriteFontType before calling this compiler.
  3. Change the asset's font type to offline-rasterized if static compilation is intended.

Example fix

// before
OfflineRasterizedFontCompiler.Compile(factory, dynamicFontAsset, srgb);

// after
if (dynamicFontAsset.FontType is OfflineRasterizedSpriteFontType)
    OfflineRasterizedFontCompiler.Compile(factory, dynamicFontAsset, srgb);
else
    DynamicSpriteFontCompiler.Compile(factory, dynamicFontAsset, srgb);
Defensive patterns

Strategy: type-guard

Type guard

bool CanCompileOffline(SpriteFontAsset asset) => asset.FontType is OfflineRasterizedSpriteFontType;

Try / catch

catch (ArgumentException ex) when (ex.Message.Contains("dynamic sprite font")) { /* route to dynamic compiler */ }

Prevention

When it happens

Trigger: Calling OfflineRasterizedFontCompiler.Compile with a SpriteFontAsset whose FontType is a dynamic font type (e.g. DynamicSpriteFontType) instead of OfflineRasterizedSpriteFontType.

Common situations: Custom build pipelines that route all sprite fonts through the offline compiler without checking FontType; switching a font asset from static to dynamic and reusing old compile code.

Understand the failure class

Background: "is not a compatible type" / "cannot merge" errors: when a value's type doesn't match what the library requires — this error's family across 65 libraries.

Related errors

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/31561de4a5b7775f. Report an issue: GitHub.

Appendix: source

Thrown at sources/engine/Stride.Assets/SpriteFont/Compiler/OfflineRasterizedFontCompiler.cs:108

namespace Stride.Assets.SpriteFont.Compiler
{
    /// <summary>
    /// Main class used to compile a Font file XML file.
    /// </summary>
    public class OfflineRasterizedFontCompiler
    {
        /// <summary>
        /// Compiles the specified font description into a <see cref="OfflineRasterizedSpriteFont" /> object.
        /// </summary>
        /// <param name="fontFactory">The font factory used to create the fonts</param>
        /// <param name="fontAsset">The font description.</param>
        /// <param name="srgb"></param>
        /// <returns>A SpriteFontData object.</returns>
        public static Graphics.SpriteFont Compile(IFontFactory fontFactory, SpriteFontAsset fontAsset, bool srgb)
        {
            var fontTypeStatic = fontAsset.FontType as OfflineRasterizedSpriteFontType;
            if (fontTypeStatic == null)
                throw new ArgumentException("Tried to compile a dynamic sprite font with compiler for static fonts");

            float lineSpacing;
            float baseLine;

            var glyphs = ImportFont(fontAsset, out lineSpacing, out baseLine);

            // Optimize.
            foreach (Glyph glyph in glyphs)
                GlyphCropper.Crop(glyph);

            Image<Rgba32> bitmap = GlyphPacker.ArrangeGlyphs(glyphs);

            // Automatically detect whether this is a monochromatic or color font?
            //if (fontAsset.Format == FontTextureFormat.Auto)
            //{
            //    bool isMono = BitmapUtils.IsRgbEntirely(Color.White, bitmap);
            //
            //    fontAsset.Format = isMono ? FontTextureFormat.CompressedMono :

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