sergio
dc8554d123
Fase F: sexto stub de pineal cerrado (6/6). mesh resultó ser un módulo de viz de grafos, no un triangle-mesh. Núcleo implementado: - buffers — NodeBuffer (stride 3: x,y,radius) + EdgeBuffer (stride 2), Vec planos contiguos, raw() para subir a GPU. - spatial_hash — uniform grid; rebuild + query (nodo bajo un punto, revisa celda + 8 vecinas). - force — layout force-directed Fruchterman-Reingold naïve O(n²): repulsión todo-par + atracción por arista + cooling. Jitter determinista para nodos coincidentes. - tree — layout de árbol por ancho de subárbol (post-order, padres centrados sobre hijos), soporta bosque, ciclos sin colgar. - camera — pan/zoom con zoom anclado al cursor (anchor-preserving). 13 tests verdes. cargo check --workspace verde. Pendiente (follow-up): hierarchical (Sugiyama) + Barnes-Hut para escalar el force-directed a grafos masivos. Pineal: 6/6 stubs cerrados. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
73 lines
2.1 KiB
Rust
73 lines
2.1 KiB
Rust
//! Cámara 2D: pan + zoom con zoom anclado a un punto de pantalla.
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/// Transformación world↔screen. `screen = (world - pan) * zoom`.
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#[derive(Debug, Clone, Copy)]
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pub struct Camera {
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pub pan: (f32, f32),
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pub zoom: f32,
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}
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impl Default for Camera {
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fn default() -> Self {
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Self { pan: (0.0, 0.0), zoom: 1.0 }
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}
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}
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impl Camera {
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pub fn new() -> Self {
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Self::default()
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}
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pub fn world_to_screen(&self, w: (f32, f32)) -> (f32, f32) {
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((w.0 - self.pan.0) * self.zoom, (w.1 - self.pan.1) * self.zoom)
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}
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pub fn screen_to_world(&self, s: (f32, f32)) -> (f32, f32) {
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(s.0 / self.zoom + self.pan.0, s.1 / self.zoom + self.pan.1)
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}
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/// Desplaza la cámara `delta` pixels de pantalla.
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pub fn pan_by(&mut self, dx: f32, dy: f32) {
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self.pan.0 -= dx / self.zoom;
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self.pan.1 -= dy / self.zoom;
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}
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/// Zoom multiplicando por `factor`, manteniendo fijo el punto de
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/// pantalla `anchor` (el world-point bajo el cursor no se mueve).
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pub fn zoom_at(&mut self, anchor: (f32, f32), factor: f32) {
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let before = self.screen_to_world(anchor);
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self.zoom = (self.zoom * factor).clamp(0.01, 1000.0);
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let after = self.screen_to_world(anchor);
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self.pan.0 += before.0 - after.0;
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self.pan.1 += before.1 - after.1;
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}
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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fn close(a: (f32, f32), b: (f32, f32)) -> bool {
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(a.0 - b.0).abs() < 1e-3 && (a.1 - b.1).abs() < 1e-3
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}
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#[test]
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fn world_screen_roundtrip() {
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let mut cam = Camera::new();
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cam.pan = (10.0, 20.0);
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cam.zoom = 2.0;
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let w = (33.0, 44.0);
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assert!(close(cam.screen_to_world(cam.world_to_screen(w)), w));
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}
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#[test]
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fn zoom_at_keeps_anchor_world_point_fixed() {
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let mut cam = Camera::new();
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let anchor = (100.0, 80.0);
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let before = cam.screen_to_world(anchor);
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cam.zoom_at(anchor, 2.5);
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let after = cam.screen_to_world(anchor);
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assert!(close(before, after), "el punto bajo el cursor no se mueve");
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}
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}
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