darkfi/bin/app/src/ui/image.rs

/* This file is part of DarkFi (https://dark.fi)
 *
 * Copyright (C) 2020-2026 Dyne.org foundation
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

use async_trait::async_trait;
use image::ImageReader;
use miniquad::TextureFormat;
use parking_lot::Mutex as SyncMutex;
use rand::{rngs::OsRng, Rng};
use std::{io::Cursor, sync::Arc};
use tracing::instrument;

use crate::{
    gfx::{
        gfxtag, DrawCall, DrawInstruction, DrawMesh, EpochCache, ManagedTexturePtr, Rectangle,
        RenderApi, Renderer,
    },
    mesh::{MeshBuilder, MeshInfo, COLOR_WHITE},
    prop::{BatchGuardPtr, PropertyAtomicGuard, PropertyRect, PropertyStr, PropertyUint32, Role},
    scene::{Pimpl, SceneNodeWeak},
    ExecutorPtr,
};

use super::{DrawUpdate, OnModify, RedrawTrigger, UIObject};

pub type ImagePtr = Arc<Image>;

pub struct Image {
    node: SceneNodeWeak,
    renderer: Renderer,
    redraw: RedrawTrigger,
    tasks: SyncMutex<Vec<smol::Task<()>>>,

    texture: SyncMutex<Option<ManagedTexturePtr>>,
    dc_key: u64,

    rect: PropertyRect,
    uv: PropertyRect,
    z_index: PropertyUint32,
    priority: PropertyUint32,
    path: PropertyStr,

    /// Cached draw instructions. Empty means stale. Entries from a dead
    /// UI epoch are evicted automatically.
    draw_cache: EpochCache<Vec<DrawInstruction>>,
}

impl Image {
    pub async fn new(node: SceneNodeWeak, renderer: Renderer, redraw: RedrawTrigger) -> Pimpl {
        let node_ref = &node.upgrade().unwrap();
        let rect = PropertyRect::wrap(node_ref, Role::Internal, "rect").unwrap();
        let uv = PropertyRect::wrap(node_ref, Role::Internal, "uv").unwrap();
        let z_index = PropertyUint32::wrap(node_ref, Role::Internal, "z_index", 0).unwrap();
        let priority = PropertyUint32::wrap(node_ref, Role::Internal, "priority", 0).unwrap();
        let path = PropertyStr::wrap(node_ref, Role::Internal, "path", 0).unwrap();

        let draw_cache = EpochCache::new(&renderer);

        let self_ = Arc::new(Self {
            node,
            renderer,
            redraw,
            tasks: SyncMutex::new(vec![]),

            texture: SyncMutex::new(None),
            dc_key: OsRng.gen(),

            rect,
            uv,
            z_index,
            priority,
            path,

            draw_cache,
        });

        Pimpl::Image(self_)
    }

    async fn reload(self_: Arc<Self>, _batch: BatchGuardPtr) {
        let texture = self_.load_texture();
        *self_.texture.lock() = Some(texture);

        self_.draw_cache.clear();
        self_.redraw.trigger();
    }

    fn load_texture(&self) -> ManagedTexturePtr {
        let path = self.path.get();

        // TODO we should NOT use panic here
        let data = Arc::new(SyncMutex::new(vec![]));
        let data2 = data.clone();
        miniquad::fs::load_file(&path.clone(), move |res| match res {
            Ok(res) => *data2.lock() = res,
            Err(e) => {
                error!(target: "ui::image", "Unable to open image: {path}: {e}");
                panic!("Resource not found! {e}");
            }
        });
        let data = std::mem::take(&mut *data.lock());
        let img =
            ImageReader::new(Cursor::new(data)).with_guessed_format().unwrap().decode().unwrap();
        let img = img.to_rgba8();

        //let img = image::ImageReader::open(path).unwrap().decode().unwrap().to_rgba8();

        let width = img.width() as u16;
        let height = img.height() as u16;
        let bmp = img.into_raw();

        self.renderer.new_texture(width, height, bmp, TextureFormat::RGBA8, gfxtag!("img"))
    }

    /// Called whenever any property changes.
    fn regen_mesh(&self) -> MeshInfo {
        let rect = self.rect.get();
        let uv = self.uv.get();
        let mesh_rect = Rectangle::from([0., 0., rect.w, rect.h]);
        let mut mesh = MeshBuilder::new(gfxtag!("img"));
        mesh.draw_box(&mesh_rect, COLOR_WHITE, &uv);
        mesh.alloc(&self.renderer)
    }

    fn get_draw_calls(
        &self,
        atom: &mut PropertyAtomicGuard,
        parent_rect: Rectangle,
    ) -> Option<DrawUpdate> {
        // Rect property is its own memo: compare before/after eval.
        let prev_rect = self.rect.get();
        self.rect.eval(atom, &parent_rect).ok()?;
        let rect = self.rect.get();
        let rect_changed = rect != prev_rect;
        self.uv.eval(atom, &rect).ok()?;

        // Mesh geometry depends on the rect; compute under the cache lock
        // so a concurrent invalidation lands before or after, never between.
        if rect_changed {
            self.draw_cache.clear();
        }
        let instrs = self.draw_cache.get_or_insert_with(|| {
            let mesh = self.regen_mesh();
            let texture = self.texture.lock().clone().expect("Node missing texture_id!");
            let mesh = DrawMesh {
                vertex_buffer: mesh.vertex_buffer,
                index_buffer: mesh.index_buffer,
                textures: Some(vec![texture]),
                num_elements: mesh.num_elements,
            };
            vec![DrawInstruction::Move(rect.pos()), DrawInstruction::Draw(mesh)]
        });

        Some(DrawUpdate {
            key: self.dc_key,
            draw_calls: vec![(
                self.dc_key,
                DrawCall::new(instrs, vec![], self.z_index.get(), "img"),
            )],
        })
    }
}

#[async_trait]
impl UIObject for Image {
    fn priority(&self) -> u32 {
        self.priority.get()
    }

    fn init(&self) {
        *self.texture.lock() = Some(self.load_texture());
    }

    async fn start(self: Arc<Self>, ex: ExecutorPtr) {
        let me = Arc::downgrade(&self);

        let mut on_modify = OnModify::new(ex, self.node.clone(), me.clone());
        // Invalidate the cache, then request a pass. Internal-role echoes
        // (the pass's own evals) are skipped.
        on_modify.when_change_external(self.rect.prop(), |self_, _| async move {
            self_.draw_cache.clear();
            self_.redraw.trigger();
        });
        on_modify.when_change_external(self.uv.prop(), |self_, _| async move {
            self_.draw_cache.clear();
            self_.redraw.trigger();
        });
        on_modify.when_change_external(self.z_index.prop(), |self_, _| async move {
            self_.draw_cache.clear();
            self_.redraw.trigger();
        });
        on_modify.when_change(self.path.prop(), Self::reload);

        *self.tasks.lock() = on_modify.tasks;
    }

    fn stop(&self) {
        self.tasks.lock().clear();
        self.draw_cache.clear();
        *self.texture.lock() = None;
    }

    #[instrument(target = "ui::button")]
    async fn draw(
        &self,
        parent_rect: Rectangle,
        atom: &mut PropertyAtomicGuard,
    ) -> Option<DrawUpdate> {
        self.get_draw_calls(atom, parent_rect)
    }
}

impl Drop for Image {
    fn drop(&mut self) {
        self.renderer.replace_draw_calls(vec![(self.dc_key, Default::default())]);
    }
}

impl std::fmt::Debug for Image {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
        write!(f, "{:?}", self.node.upgrade().unwrap())
    }
}