Loading…
CompareOpen in Google Play
This app isn't in any of our charts yet.
App elements of Projective geometry: Homography, Pascal's Theorem, Desargues
App elements of Projective geometry: Homography, Pascal's Theorem, Desargues Theorem, Double relation. Android application (Java), multilingual with four interactive scenes. The dots are dragged with a finger. 1. **Homography** – the unit square is plotted on a quadrilateral ABCD (3×3 matrix of 4 pairs of points, Gaussian method). The vanishing points V₁, V₂ are shown. and the horizon – the image of the infinite line. 2. **Pascal's Theorem** – hexagon inscribed in an ellipse; X, Y, Z are collinear. 3. **Desargues' Theorem** – two perspective triangles and the perspective axis. 4. **Double relation** – central projection of 4 points; (A,B;C,D) remains the same. All geometry is in homogeneous coordinates (`geometry/Vec3`): line through two points = cross product, intersection of two lines = cross product. Infinite points are handled without special cases. ## Languages English (default), Bulgarian, French, German and Spanish. The language is changed from a menu in the toolbar and does not depend on the device language (`AppCompatDelegate.setApplicationLocales`). The selection is saved; on Android 13+, the language can also be changed from the app's system settings. ## Structure - `geometry/` – Vec3, Projective, Homography (pure Java, no Android) - `view/` – GeometryView (base class: dragging, drawing lines) and the four scenes - `MainActivity` – tabs (TabLayout), tooltip, numeric information, "Reset" button