tonhowtf/omniget · error

não gravei o PNG

Error message

não gravei o PNG: {}

What it means

Thrown in write_image when encoding a sliced/packed sprite cell (or batch output) to PNG in memory fails. The `image` crate's write_to returned an error, which is wrapped with context naming the failed PNG write.

Solutions

1. Check the underlying image::ImageError message in the context string for the exact encoding problem.
2. Convert the image to a supported color type before writing (e.g. to_rgba8, which this path already applies via ImageRgba8).
3. Ensure output directories are writable and there is disk space before calling write_image.
4. If JPEG was intended, confirm the format argument maps to jpg so the encode_jpeg branch is taken.

Example fix

// before
DynamicImage::ImageRgba8(img.clone())
    .write_to(&mut buf, image::ImageFormat::Png)
    .map_err(|e| anyhow!("não gravei o PNG: {}", e))?;
// after
let img = DynamicImage::ImageRgba8(img.clone());
img.write_to(&mut buf, image::ImageFormat::Png)
    .map_err(|e| anyhow!("não gravei o PNG: {}", e))?; // adds explicit rgba8 + logging of the error chain

match write_image(&img, &path, quality) {
    Err(e) if format!("{e}").contains("não gravei o PNG") => {
        tracing::error!("falha ao codificar PNG {}: {e:#}", path.display());
        // fallback: escrever como PNG via codec alternativo ou reportar ao usuário
    }
    other => other?,
}

When it happens

Trigger: Calling write_image (via slice, pack, or batch) with a format that is not jpg, where DynamicImage::write_to(.., ImageFormat::Png) fails — typically an unsupported color type/encoding parameters combination, or an out-of-memory allocation for huge buffers.

Common situations: Writing very large spritesheets exceeding memory limits; unusual image color formats passed through; disk-full scenarios manifesting as encode/IO errors in downstream fs::write.

Understand the failure class

Background: "failed to write file", "Could not save figure", "Error saving remote file" — file write failed: causes and fixes across languages and libraries — this error's family across 38 libraries.

Related errors

• não gravei o PNG
• não gravei o PNG
• não abri
• nenhum quadro pôde ser aberto
• não gravei o JPEG

AI-assisted analysis of tonhowtf/omniget@8600b91f42 (2026-09-12). Data as JSON: /api/errors/46be3e8eb1fdce82. Report an issue: GitHub.

Appendix: source

Thrown at src-tauri/omniget-core/src/core/tools/image_sprite.rs:300

    }
}

fn ext_of(format: &str) -> &'static str {
    if format.eq_ignore_ascii_case("jpeg") || format.eq_ignore_ascii_case("jpg") {
        "jpg"
    } else {
        "png"
    }
}

fn write_image(img: &RgbaImage, path: &Path, format: &str, quality: u8) -> anyhow::Result<u64> {
    let data = if ext_of(format) == "jpg" {
        super::image_compress::encode_jpeg(&DynamicImage::ImageRgba8(img.clone()), quality)?
    } else {
        let mut buf = std::io::Cursor::new(Vec::new());
        DynamicImage::ImageRgba8(img.clone())
            .write_to(&mut buf, image::ImageFormat::Png)
            .map_err(|e| anyhow!("não gravei o PNG: {}", e))?;
        buf.into_inner()
    };
    if let Some(parent) = path.parent() {
        if !parent.as_os_str().is_empty() {
            std::fs::create_dir_all(parent)?;
        }
    }
    std::fs::write(path, &data)?;
    Ok(data.len() as u64)
}

/// JSON de atlas no formato de mapa (o mesmo shape que o TexturePacker usa no
/// preset "JSON (Hash)"), que é o que engine e bundler já sabem ler.
pub fn atlas_json(frames: &[SpriteFrame], sheet: &str, w: u32, h: u32) -> String {
    let mut map = serde_json::Map::new();
    for f in frames {
        map.insert(
            f.name.clone(),

View on GitHub (pinned to 8600b91f42)