From dff30811942a67c4318452a1cf4273306d9f6012 Mon Sep 17 00:00:00 2001
From: "Eevee (Evelyn Woods)" <eevee.git@veekun.com>
Date: Sat, 28 Nov 2020 11:07:02 -0700
Subject: [PATCH] Editor: center/pad the level, fix some bugs with pencil
 drawing

---
 index.html        |  7 ++++++-
 js/main-editor.js | 37 +++++++++++++++++++++++++------------
 js/util.js        | 17 ++++++++---------
 style.css         | 25 +++++++++++++++++++++----
 4 files changed, 60 insertions(+), 26 deletions(-)

diff --git a/index.html b/index.html
index c829e7e..6682e44 100644
--- a/index.html
+++ b/index.html
@@ -191,7 +191,12 @@
             also deal with levels vs level /packs/ somehow, not sure how that'll work (including downloading them, yeargh?)
             -->
         </header>
-        <div class="level"><!-- level canvas and any overlays go here --></div>
+        <div class="editor-canvas">
+            <div class="-container">
+                <!-- level canvas and any overlays go here -->
+                <!-- the container is to allow them to scroll as a single unit -->
+            </div>
+        </div>
         <nav class="controls">
             <div id="editor-toolbar">
                 <!-- tools go here -->
diff --git a/js/main-editor.js b/js/main-editor.js
index 0b485a0..fabb934 100644
--- a/js/main-editor.js
+++ b/js/main-editor.js
@@ -84,6 +84,19 @@ class MouseOperation {
         this.cleanup();
     }
 
+    *iter_touched_cells(gxf, gyf) {
+        for (let pt of walk_grid(
+            this.gx1f, this.gy1f, gxf, gyf,
+            // Bound the grid walk to one cell beyond the edges of the level, so that dragging the
+            // mouse in from outside the actual edges still works reliably
+            -1, -1, this.editor.stored_level.size_x, this.editor.stored_level.size_y))
+        {
+            if (this.editor.is_in_bounds(...pt)) {
+                yield pt;
+            }
+        }
+    }
+
     // Implement these
     start() {}
     step(x, y) {}
@@ -94,8 +107,9 @@ class MouseOperation {
 
 class PanOperation extends MouseOperation {
     step(mx, my) {
-        this.editor.viewport_el.scrollLeft -= mx - this.mx1;
-        this.editor.viewport_el.scrollTop -= my - this.my1;
+        let target = this.editor.viewport_el.parentNode;
+        target.scrollLeft -= mx - this.mx1;
+        target.scrollTop -= my - this.my1;
     }
 }
 
@@ -107,7 +121,7 @@ class PencilOperation extends DrawOperation {
         this.editor.place_in_cell(this.gx1, this.gy1, this.editor.palette_selection);
     }
     step(mx, my, gxf, gyf) {
-        for (let [x, y] of walk_grid(this.gx1f, this.gy1f, gxf, gyf)) {
+        for (let [x, y] of this.iter_touched_cells(gxf, gyf)) {
             this.editor.place_in_cell(x, y, this.editor.palette_selection);
         }
     }
@@ -125,7 +139,7 @@ class ForceFloorOperation extends DrawOperation {
         // the same direction, but shouldn't
         let i = 0;
         let prevx, prevy;
-        for (let [x, y] of walk_grid(this.gx1f, this.gy1f, gxf, gyf)) {
+        for (let [x, y] of this.iter_touched_cells(gxf, gyf)) {
             i++;
             // The very first cell is the one the mouse was already in, and we don't
             // have a movement direction yet, so leave that alone
@@ -542,7 +556,7 @@ export class Editor extends PrimaryView {
     constructor(conductor) {
         super(conductor, document.body.querySelector('main#editor'));
 
-        this.viewport_el = this.root.querySelector('.level');
+        this.viewport_el = this.root.querySelector('.editor-canvas .-container');
 
         // FIXME don't hardcode size here, convey this to renderer some other way
         this.renderer = new CanvasRenderer(this.conductor.tileset, 32);
@@ -575,6 +589,7 @@ export class Editor extends PrimaryView {
             }
             else if (ev.button === 1) {
                 // Middle button: always pan
+                console.log("middle button!");
                 this.mouse_op = new PanOperation(this, ev);
 
                 ev.preventDefault();
@@ -593,7 +608,10 @@ export class Editor extends PrimaryView {
                 this.renderer.draw();
             }
         });
-        this.viewport_el.addEventListener('mousemove', ev => {
+        // Once the mouse is down, we should accept mouse movement anywhere
+        window.addEventListener('mousemove', ev => {
+            if (! this.active)
+                return;
             if (! this.mouse_op)
                 return;
             if ((ev.buttons & this.mouse_op.button_mask) === 0) {
@@ -766,7 +784,7 @@ export class Editor extends PrimaryView {
         }
     }
 
-    is_in_level(x, y) {
+    is_in_bounds(x, y) {
         return 0 <= x && x < this.stored_level.size_x && 0 <= y && y < this.stored_level.size_y;
     }
 
@@ -775,11 +793,6 @@ export class Editor extends PrimaryView {
         if (! name)
             return;
 
-        // TODO seems like a big problem to silently ignore, but it can happen from mouse
-        // coordinates while drawing
-        if (! this.is_in_level(x, y))
-            return;
-
         let type = TILE_TYPES[name];
         let direction;
         if (type.is_actor) {
diff --git a/js/util.js b/js/util.js
index dd762be..c738629 100644
--- a/js/util.js
+++ b/js/util.js
@@ -153,7 +153,7 @@ export function string_from_buffer_ascii(buf, start = 0, len) {
 }
 
 // Cast a line through a grid and yield every cell it touches
-export function* walk_grid(x0, y0, x1, y1) {
+export function* walk_grid(x0, y0, x1, y1, min_a, min_b, max_a, max_b) {
     // TODO if the ray starts outside the grid (extremely unlikely), we should
     // find the point where it ENTERS the grid, otherwise the 'while'
     // conditions below will stop immediately
@@ -193,27 +193,24 @@ export function* walk_grid(x0, y0, x1, y1) {
         step_a = -step_a;
         offset_x = 1 - offset_x;
     }
-    // Zero offset means we're on a grid line, so we're actually a full cell
-    // away from the next grid line
-    if (offset_x === 0) {
+    else if (offset_x === 0) {
+        // Zero offset means we're on a grid line, so we're a full cell away from the next grid line
+        // (if we're moving forward; if we're moving backward, the next cell really is 0 away)
         offset_x = 1;
     }
     let step_b = 1;
-    let offset_y = 1 - (y0  - b);
+    let offset_y = 1 - (y0 - b);
     if (dy < 0) {
         dy = -dy;
         step_b = -step_b;
         offset_y = 1 - offset_y;
     }
-    if (offset_y === 0) {
+    else if (offset_y === 0) {
         offset_y = 1;
     }
 
     let err = dy * offset_x - dx * offset_y;
 
-    let min_a = 0, min_b = 0;
-    // TODO get these passed in fool
-    let max_a = 31, max_b = 31;
     if (dx > dy) {
         // Main axis is x/a
         while (min_a <= a && a <= max_a && min_b <= b && b <= max_b) {
@@ -252,6 +249,8 @@ export function* walk_grid(x0, y0, x1, y1) {
         }
     }
 }
+window.walk_grid = walk_grid;
+// console.table(Array.from(walk_grid(13, 27.133854389190674, 12.90625, 27.227604389190674)))
 
 // Root class to indirect over where we might get files from
 // - a pool of uploaded in-memory files
diff --git a/style.css b/style.css
index 9688dc4..fbd91fd 100644
--- a/style.css
+++ b/style.css
@@ -883,14 +883,31 @@ main.--has-demo .demo-controls {
     margin: auto 1em;
 }
 
-#editor .level {
+#editor .editor-canvas {
     grid-area: level;
     position: relative;
     overflow: auto;
-    /* Padding and background make it easier to tell when we're at the edge of the map */
-    /* TODO padding should be half a cell, and svg should respect it too */
-    /* padding: 1em; */
+    /* Flex layout to center the canvas and overlay together */
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    align-items: safe center;
+    justify-content: safe center;
     background: #202020;
+    border: 0.125em solid black;
+}
+#editor .editor-canvas .-container {
+    /* Give the canvas/overlay a bit of a margin; it has to be a border because, due to some quirk
+     * of overflowing flexboxes I guess, padding and margins won't extend the scroll area on the
+     * right and bottom */
+    /* TODO padding should be half a cell? */
+    border: 1em solid transparent;
+}
+#editor .editor-canvas canvas {
+    display: block;
+    width: calc(var(--viewport-width) * var(--tile-width) * var(--scale));
+    --viewport-width: 9;
+    --viewport-height: 9;
 }
 /* SVG overlays */
 #editor svg.level-editor-overlay {