From d6eaee23ecfe84a64f1ba8000f85dd70a659d4ac Mon Sep 17 00:00:00 2001
From: frederic wagner <frederic.wagner@imag.fr>
Date: Fri, 30 Jun 2023 11:10:49 +0200
Subject: [PATCH] gipy: fixing tile_is_on_screen

previous algorithm was incorrect
---
 apps/gipy/ChangeLog |  1 +
 apps/gipy/app.js    | 58 +++++++++++++++++++++++++++------------------
 2 files changed, 36 insertions(+), 23 deletions(-)

diff --git a/apps/gipy/ChangeLog b/apps/gipy/ChangeLog
index 6371fbdf1..8646ba11a 100644
--- a/apps/gipy/ChangeLog
+++ b/apps/gipy/ChangeLog
@@ -86,3 +86,4 @@
 	* Display path in leaflet
 	* Reduce framerate if locked
 	* Stroke to move around in the map
+	* Fix for missing paths in display
diff --git a/apps/gipy/app.js b/apps/gipy/app.js
index 94f9ab450..ddd1a2c08 100644
--- a/apps/gipy/app.js
+++ b/apps/gipy/app.js
@@ -1,4 +1,4 @@
-let simulated = false;
+let simulated = true;
 let displaying = false;
 let in_menu = false;
 let go_backwards = false;
@@ -243,6 +243,7 @@ class Map {
     let local_y = displayed_y - this.start_coordinates[1];
     let tile_x = Math.floor(local_x / this.side);
     let tile_y = Math.floor(local_y / this.side);
+
     let limit = 1;
     if (!zoomed) {
       limit = 2;
@@ -266,6 +267,18 @@ class Map {
             sin_direction
           )
         ) {
+//           let colors = [
+//             [0, 0, 0],
+//             [0, 0, 1],
+//             [0, 1, 0],
+//             [0, 1, 1],
+//             [1, 0, 0],
+//             [1, 0, 1],
+//             [1, 1, 0],
+//             [1, 1, 0.5],
+//             [0.5, 0, 0.5],
+//             [0, 0.5, 0.5],
+//           ];
           if (this.color[0] == 1 && this.color[1] == 0 && this.color[2] == 0) {
             this.display_thick_tile(
               x,
@@ -301,33 +314,32 @@ class Map {
     cos_direction,
     sin_direction
   ) {
-    let center_x = g.getWidth() / 2;
-    let center_y = g.getHeight() / 2 + Y_OFFSET;
+    let width = g.getWidth();
+    let height = g.getHeight();
+    let center_x = width / 2;
+    let center_y = height / 2 + Y_OFFSET;
     let side = this.side;
-    let x1 = tile_x * side;
-    let y1 = tile_y * side;
-    let x2 = x1 + side;
-    let y2 = y1 + side;
-    let scaled_x1 = (x1 - current_x) * scale_factor;
-    let scaled_y1 = (y1 - current_y) * scale_factor;
-    let rotated_x1 = scaled_x1 * cos_direction - scaled_y1 * sin_direction;
-    let rotated_y1 = scaled_x1 * sin_direction + scaled_y1 * cos_direction;
-    let scaled_x2 = (x2 - current_x) * scale_factor;
-    let scaled_y2 = (y2 - current_y) * scale_factor;
-    let rotated_x2 = scaled_x2 * cos_direction - scaled_y2 * sin_direction;
-    let rotated_y2 = scaled_x2 * sin_direction + scaled_y2 * cos_direction;
+    let tile_center_x = (tile_x + 0.5) * side;
+    let tile_center_y = (tile_y + 0.5) * side;
+    let scaled_center_x = (tile_center_x - current_x) * scale_factor;
+    let scaled_center_y = (tile_center_y - current_y) * scale_factor;
+    let rotated_center_x = scaled_center_x * cos_direction - scaled_center_y * sin_direction;
+    let rotated_center_y = scaled_center_x * sin_direction + scaled_center_y * cos_direction;
+    let on_screen_center_x = center_x - rotated_center_x;
+    let on_screen_center_y = center_y + rotated_center_y;
 
-    if (center_x < rotated_x1 && center_x < rotated_x2) {
-      return false;
-    }
-    if (-center_x > rotated_x1 && -center_x > rotated_x2) {
-      return false;
-    }
+    let scaled_side = side * scale_factor;
 
-    if (center_y < rotated_y1 && center_y < rotated_y2) {
+    if (on_screen_center_x + scaled_side <= 0) {
       return false;
     }
-    if (-center_y > rotated_y1 && -center_y > rotated_y2) {
+    if (on_screen_center_x - scaled_side >= width) {
+      return false;
+    }
+    if (on_screen_center_y + scaled_side <= 0) {
+      return false;
+    }
+    if (on_screen_center_y - scaled_side >= height) {
       return false;
     }
     return true;