fix: stabilize match3d demo discovery

server-rs/crates/api-server/src/generated_asset_sheets.rs

@@ -247,8 +247,14 @@ pub(crate) fn slice_generated_asset_sheet_two_items_per_row(
 
     let items_per_row = grid_size / views_per_item;
     let max_item_count = grid_size.saturating_mul(items_per_row);
-    let mut slices = Vec::with_capacity(item_names.len().min(max_item_count));
-    for item_index in 0..item_names.len().min(max_item_count) {
+    let item_count = item_names.len().min(max_item_count);
+    if let Some(slices) =
+        slice_generated_asset_sheet_by_alpha_components(&source, item_count, views_per_item)?
+    {
+        return Ok(slices);
+    }
+    let mut slices = Vec::with_capacity(item_count);
+    for item_index in 0..item_count {
         let row = (item_index / items_per_row) as u32;
         let start_col = ((item_index % items_per_row) * views_per_item) as u32;
         let mut views = Vec::with_capacity(views_per_item);
@@ -469,6 +475,12 @@ struct GeneratedAssetSheetCellBounds {
     y1: u32,
 }
 
+#[derive(Clone, Copy, Debug)]
+struct GeneratedAssetSheetDetectedComponent {
+    bounds: GeneratedAssetSheetCellBounds,
+    area: u32,
+}
+
 impl GeneratedAssetSheetCellBounds {
     fn width(self) -> u32 {
         self.x1.saturating_sub(self.x0).max(1)
@@ -487,6 +499,272 @@ impl GeneratedAssetSheetCellBounds {
     }
 }
 
+fn detect_generated_asset_sheet_alpha_components(
+    image: &image::RgbaImage,
+) -> Vec<GeneratedAssetSheetDetectedComponent> {
+    let (width, height) = image.dimensions();
+    let pixel_count = width.saturating_mul(height) as usize;
+    if width == 0 || height == 0 || pixel_count == 0 {
+        return Vec::new();
+    }
+
+    let mut visited = vec![0u8; pixel_count];
+    let min_area = resolve_generated_asset_sheet_alpha_component_min_area(width, height);
+    let mut components = Vec::new();
+    for start in 0..pixel_count {
+        if visited[start] != 0 {
+            continue;
+        }
+        let start_pixel = image
+            .get_pixel(start as u32 % width, start as u32 / width)
+            .0;
+        if !is_generated_asset_sheet_visible_pixel(start_pixel) {
+            visited[start] = 1;
+            continue;
+        }
+
+        let component =
+            flood_fill_generated_asset_sheet_alpha_component(image, &mut visited, start);
+        if component.area >= min_area {
+            components.push(component);
+        }
+    }
+
+    components
+}
+
+fn slice_generated_asset_sheet_by_alpha_components(
+    source: &image::DynamicImage,
+    item_count: usize,
+    views_per_item: usize,
+) -> Result<Option<Vec<Vec<GeneratedAssetSheetSliceImage>>>, AppError> {
+    if item_count == 0 {
+        return Ok(Some(Vec::new()));
+    }
+
+    let sheet_grid_size = views_per_item.checked_mul(2).ok_or_else(|| {
+        AppError::from_status(StatusCode::BAD_REQUEST).with_details(json!({
+            "provider": GENERATED_ASSET_SHEET_PROVIDER,
+            "message": "系列素材图集的每物品视图数超出可支持范围。",
+        }))
+    })?;
+    let sheet_grid_size_u32 = u32::try_from(sheet_grid_size).map_err(|_| {
+        AppError::from_status(StatusCode::BAD_REQUEST).with_details(json!({
+            "provider": GENERATED_ASSET_SHEET_PROVIDER,
+            "message": "系列素材图集的每物品视图数超出可支持范围。",
+        }))
+    })?;
+
+    let source = source.to_rgba8();
+    let (width, height) = source.dimensions();
+    if width == 0 || height == 0 {
+        return Ok(None);
+    }
+
+    let cell_width = width / sheet_grid_size_u32;
+    let cell_height = height / sheet_grid_size_u32;
+    if cell_width == 0 || cell_height == 0 {
+        return Ok(None);
+    }
+
+    let components = detect_generated_asset_sheet_alpha_components(&source);
+    let expected_slot_count = item_count.saturating_mul(views_per_item);
+    if components.len() < expected_slot_count {
+        return Ok(None);
+    }
+
+    let components = sort_generated_asset_sheet_components_by_original_position(
+        components,
+        cell_height as f32 * 0.65,
+    );
+    let components = components
+        .into_iter()
+        .take(expected_slot_count)
+        .collect::<Vec<_>>();
+    if components.len() < expected_slot_count {
+        return Ok(None);
+    }
+
+    let mut slices = Vec::with_capacity(item_count);
+    for item_index in 0..item_count {
+        let mut views = Vec::with_capacity(views_per_item);
+        for view_index in 0..views_per_item {
+            let slot_index = item_index * views_per_item + view_index;
+            let component = &components[slot_index];
+            let pad_x = (cell_width / 16).clamp(4, 16);
+            let pad_y = (cell_height / 16).clamp(4, 16);
+            let crop_x = component.bounds.x0.saturating_sub(pad_x);
+            let crop_y = component.bounds.y0.saturating_sub(pad_y);
+            let crop_x1 = component.bounds.x1.saturating_add(pad_x).min(width);
+            let crop_y1 = component.bounds.y1.saturating_add(pad_y).min(height);
+            let cropped = image::DynamicImage::ImageRgba8(
+                image::imageops::crop_imm(
+                    &source,
+                    crop_x,
+                    crop_y,
+                    crop_x1.saturating_sub(crop_x).max(1),
+                    crop_y1.saturating_sub(crop_y).max(1),
+                )
+                .to_image(),
+            );
+            let mut cursor = std::io::Cursor::new(Vec::new());
+            cropped
+                .write_to(&mut cursor, ImageFormat::Png)
+                .map_err(|error| {
+                    AppError::from_status(StatusCode::BAD_GATEWAY).with_details(json!({
+                        "provider": GENERATED_ASSET_SHEET_PROVIDER,
+                        "message": format!("系列素材图集切割失败：{error}"),
+                    }))
+                })?;
+            views.push(GeneratedAssetSheetSliceImage {
+                bytes: cursor.into_inner(),
+            });
+        }
+        slices.push(views);
+    }
+
+    Ok(Some(slices))
+}
+
+fn resolve_generated_asset_sheet_alpha_component_min_area(width: u32, height: u32) -> u32 {
+    (width.saturating_mul(height) / 12_000).clamp(16, 800)
+}
+
+fn flood_fill_generated_asset_sheet_alpha_component(
+    image: &image::RgbaImage,
+    visited: &mut [u8],
+    start: usize,
+) -> GeneratedAssetSheetDetectedComponent {
+    let (width, height) = image.dimensions();
+    let mut stack = vec![start];
+    visited[start] = 1;
+
+    let mut min_x = start as u32 % width;
+    let mut max_x = min_x;
+    let mut min_y = start as u32 / width;
+    let mut max_y = min_y;
+    let mut area = 0u32;
+
+    while let Some(index) = stack.pop() {
+        let x = index as u32 % width;
+        let y = index as u32 / width;
+        area = area.saturating_add(1);
+        min_x = min_x.min(x);
+        max_x = max_x.max(x);
+        min_y = min_y.min(y);
+        max_y = max_y.max(y);
+
+        visit_generated_asset_sheet_alpha_component_neighbor(
+            image,
+            visited,
+            &mut stack,
+            index.wrapping_sub(1),
+            x > 0,
+        );
+        visit_generated_asset_sheet_alpha_component_neighbor(
+            image,
+            visited,
+            &mut stack,
+            index + 1,
+            x + 1 < width,
+        );
+        visit_generated_asset_sheet_alpha_component_neighbor(
+            image,
+            visited,
+            &mut stack,
+            index.saturating_sub(width as usize),
+            y > 0,
+        );
+        visit_generated_asset_sheet_alpha_component_neighbor(
+            image,
+            visited,
+            &mut stack,
+            index + width as usize,
+            y + 1 < height,
+        );
+    }
+
+    GeneratedAssetSheetDetectedComponent {
+        bounds: GeneratedAssetSheetCellBounds {
+            x0: min_x,
+            y0: min_y,
+            x1: max_x.saturating_add(1),
+            y1: max_y.saturating_add(1),
+        },
+        area,
+    }
+}
+
+fn visit_generated_asset_sheet_alpha_component_neighbor(
+    image: &image::RgbaImage,
+    visited: &mut [u8],
+    stack: &mut Vec<usize>,
+    index: usize,
+    in_bounds: bool,
+) {
+    if !in_bounds || visited.get(index).copied().unwrap_or(1) != 0 {
+        return;
+    }
+    let (width, _) = image.dimensions();
+    let pixel = image
+        .get_pixel(index as u32 % width, index as u32 / width)
+        .0;
+    if !is_generated_asset_sheet_visible_pixel(pixel) {
+        visited[index] = 1;
+        return;
+    }
+
+    visited[index] = 1;
+    stack.push(index);
+}
+
+fn sort_generated_asset_sheet_components_by_original_position(
+    components: Vec<GeneratedAssetSheetDetectedComponent>,
+    row_tolerance_hint: f32,
+) -> Vec<GeneratedAssetSheetDetectedComponent> {
+    if components.is_empty() {
+        return components;
+    }
+
+    let average_height = components
+        .iter()
+        .map(|component| component.bounds.height() as f32)
+        .sum::<f32>()
+        / components.len() as f32;
+    let row_tolerance = row_tolerance_hint.max(average_height * 0.65).max(2.0);
+    let mut rows: Vec<Vec<GeneratedAssetSheetDetectedComponent>> = Vec::new();
+
+    let mut sorted = components;
+    sorted.sort_by(|left, right| {
+        left.bounds
+            .y0
+            .cmp(&right.bounds.y0)
+            .then_with(|| left.bounds.x0.cmp(&right.bounds.x0))
+    });
+    for component in sorted {
+        let center_y = component.bounds.y0 as f32 + component.bounds.height() as f32 / 2.0;
+        if let Some(row) = rows.iter_mut().find(|items| {
+            let row_center = items
+                .iter()
+                .map(|item| item.bounds.y0 as f32 + item.bounds.height() as f32 / 2.0)
+                .sum::<f32>()
+                / items.len() as f32;
+            (row_center - center_y).abs() <= row_tolerance
+        }) {
+            row.push(component);
+        } else {
+            rows.push(vec![component]);
+        }
+    }
+
+    rows.into_iter()
+        .flat_map(|mut row| {
+            row.sort_by(|left, right| left.bounds.x0.cmp(&right.bounds.x0));
+            row
+        })
+        .collect()
+}
+
 fn resolve_generated_asset_sheet_cell_crop(
     source: &image::DynamicImage,
     grid_size: u32,
@@ -1674,6 +1952,193 @@ mod tests {
         assert_eq!(slices[1].len(), 5);
     }
 
+    #[test]
+    fn generated_asset_sheet_two_items_per_row_uses_alpha_components_when_views_cross_cell_boundaries() {
+        let width = 1_000;
+        let height = 1_000;
+        let item_names = vec!["樱桃".to_string(), "苹果".to_string()];
+        let colors = [
+            ([220, 20, 24, 255], [246, 178, 46, 255]),
+            ([230, 88, 20, 255], [248, 196, 78, 255]),
+            ([240, 170, 28, 255], [250, 214, 110, 255]),
+            ([90, 180, 54, 255], [188, 236, 86, 255]),
+            ([20, 150, 200, 255], [92, 214, 248, 255]),
+            ([70, 96, 220, 255], [124, 150, 252, 255]),
+            ([150, 80, 210, 255], [188, 118, 248, 255]),
+            ([210, 80, 170, 255], [248, 130, 204, 255]),
+            ([140, 92, 48, 255], [190, 136, 82, 255]),
+            ([34, 34, 34, 255], [88, 88, 88, 255]),
+        ];
+        let positions = [
+            (90u32, 40u32),
+            (190, 44),
+            (290, 38),
+            (390, 42),
+            (490, 36),
+            (590, 540),
+            (690, 536),
+            (790, 544),
+            (890, 538),
+            (960, 542),
+        ];
+        let mut sheet = image::RgbaImage::from_pixel(width, height, image::Rgba([0, 0, 0, 0]));
+        for (index, (left_color, right_color)) in colors.iter().enumerate() {
+            let (start_x, start_y) = positions[index];
+            for y in start_y..start_y + 36 {
+                for x in start_x..start_x + 16 {
+                    sheet.put_pixel(x, y, image::Rgba(*left_color));
+                }
+                for x in start_x + 16..start_x + 32 {
+                    sheet.put_pixel(x, y, image::Rgba(*right_color));
+                }
+            }
+        }
+        let mut encoded = std::io::Cursor::new(Vec::new());
+        image::DynamicImage::ImageRgba8(sheet)
+            .write_to(&mut encoded, ImageFormat::Png)
+            .expect("sheet should encode");
+        let image = DownloadedOpenAiImage {
+            bytes: encoded.into_inner(),
+            mime_type: "image/png".to_string(),
+            extension: "png".to_string(),
+        };
+
+        let slices = slice_generated_asset_sheet_two_items_per_row(&image, &item_names, 10, 5)
+            .expect("sheet should slice");
+
+        assert_eq!(slices.len(), 2);
+        assert_eq!(slices[0].len(), 5);
+        assert_eq!(slices[1].len(), 5);
+        for (index, (left_color, right_color)) in colors.iter().enumerate() {
+            let item_index = index / 5;
+            let view_index = index % 5;
+            let decoded = image::load_from_memory(slices[item_index][view_index].bytes.as_slice())
+                .expect("view should decode")
+                .to_rgba8();
+            assert!(
+                decoded.pixels().any(|pixel| pixel.0 == *left_color),
+                "第 {index} 个格位应保留左侧主体颜色"
+            );
+            assert!(
+                decoded.pixels().any(|pixel| pixel.0 == *right_color),
+                "第 {index} 个格位应保留右侧主体颜色"
+            );
+        }
+    }
+
+    #[test]
+    fn generated_asset_sheet_two_items_per_row_keeps_cell_order_when_views_are_vertically_scrambled()
+     {
+        let width = 1_000;
+        let height = 1_000;
+        let item_names = vec!["樱桃".to_string(), "苹果".to_string()];
+        let colors = [
+            [220, 20, 24, 255],
+            [230, 88, 20, 255],
+            [240, 170, 28, 255],
+            [90, 180, 54, 255],
+            [20, 150, 200, 255],
+            [70, 96, 220, 255],
+            [150, 80, 210, 255],
+            [210, 80, 170, 255],
+            [140, 92, 48, 255],
+            [34, 34, 34, 255],
+        ];
+        let top_offsets = [62u32, 18, 74, 26, 68, 20, 72, 24, 66, 22];
+        let mut sheet = image::RgbaImage::from_pixel(width, height, image::Rgba([0, 0, 0, 0]));
+        for (index, color) in colors.iter().enumerate() {
+            let start_x = index as u32 * 100 + 34;
+            let start_y = top_offsets[index];
+            for y in start_y..start_y + 36 {
+                for x in start_x..start_x + 32 {
+                    sheet.put_pixel(x, y, image::Rgba(*color));
+                }
+            }
+        }
+        let mut encoded = std::io::Cursor::new(Vec::new());
+        image::DynamicImage::ImageRgba8(sheet)
+            .write_to(&mut encoded, ImageFormat::Png)
+            .expect("sheet should encode");
+        let image = DownloadedOpenAiImage {
+            bytes: encoded.into_inner(),
+            mime_type: "image/png".to_string(),
+            extension: "png".to_string(),
+        };
+
+        let slices = slice_generated_asset_sheet_two_items_per_row(&image, &item_names, 10, 5)
+            .expect("sheet should slice");
+
+        assert_eq!(slices.len(), 2);
+        assert_eq!(slices[0].len(), 5);
+        assert_eq!(slices[1].len(), 5);
+        for (index, color) in colors.iter().enumerate() {
+            let item_index = index / 5;
+            let view_index = index % 5;
+            let decoded = image::load_from_memory(slices[item_index][view_index].bytes.as_slice())
+                .expect("view should decode")
+                .to_rgba8();
+            assert!(
+                decoded.pixels().any(|pixel| pixel.0 == *color),
+                "第 {index} 个格位应按列顺序保留对应主体颜色"
+            );
+        }
+    }
+
+    #[test]
+    fn generated_asset_sheet_two_items_per_row_falls_back_to_fixed_grid_when_alpha_components_are_insufficient()
+     {
+        let width = 1_000;
+        let height = 1_000;
+        let item_names = vec!["樱桃".to_string(), "苹果".to_string()];
+        let mut sheet = image::RgbaImage::new(width, height);
+        for row in 0..10 {
+            for col in 0..10 {
+                let color = image::Rgba([
+                    16 + row as u8 * 20,
+                    12 + col as u8 * 18,
+                    230 - row as u8 * 12,
+                    255,
+                ]);
+                for y in row * 100..(row + 1) * 100 {
+                    for x in col * 100..(col + 1) * 100 {
+                        sheet.put_pixel(x, y, color);
+                    }
+                }
+            }
+        }
+        let mut encoded = std::io::Cursor::new(Vec::new());
+        image::DynamicImage::ImageRgba8(sheet)
+            .write_to(&mut encoded, ImageFormat::Png)
+            .expect("sheet should encode");
+        let image = DownloadedOpenAiImage {
+            bytes: encoded.into_inner(),
+            mime_type: "image/png".to_string(),
+            extension: "png".to_string(),
+        };
+
+        let slices = slice_generated_asset_sheet_two_items_per_row(&image, &item_names, 10, 5)
+            .expect("sheet should slice");
+
+        assert_eq!(slices.len(), 2);
+        assert_eq!(slices[0].len(), 5);
+        assert_eq!(slices[1].len(), 5);
+        for (item_index, views) in slices.iter().enumerate() {
+            for (view_index, view) in views.iter().enumerate() {
+                let decoded = image::load_from_memory(view.bytes.as_slice())
+                    .expect("view should decode")
+                    .to_rgba8();
+                let pixel = decoded.get_pixel(decoded.width() / 2, decoded.height() / 2);
+                let row = 0u8;
+                let col = (item_index * 5 + view_index) as u8;
+                assert_eq!(
+                    pixel.0,
+                    [16 + row * 20, 12 + col * 18, 230 - row * 12, 255,],
+                    "item {item_index} view {view_index} should keep the fixed grid fallback"
+                );
+            }
+        }
+    }
+
     #[test]
     fn generated_asset_sheet_prepare_put_request_packs_prompt_metadata() {
         let request = prepare_generated_asset_sheet_put_request(GeneratedAssetSheetPersistInput {