From 82500582964e23a3c06e337c5178a03307101d35 Mon Sep 17 00:00:00 2001
From: Krzosa Karol <krzosa.karol@gmail.com>
Date: Tue, 2 Jul 2024 11:06:04 +0200
Subject: [PATCH] Scroll clamping

---
 src/text_editor/layout.cpp |  9 +++++++++
 src/text_editor/main.cpp   | 13 +++++++------
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/text_editor/layout.cpp b/src/text_editor/layout.cpp
index 68eb493..9761433 100644
--- a/src/text_editor/layout.cpp
+++ b/src/text_editor/layout.cpp
@@ -12,6 +12,7 @@ struct LayoutRow {
 struct Layout {
     Array<LayoutRow> rows;
     Vec2             buffer_world_pixel_size;
+    LayoutColumn    *max_column;
 };
 
 struct HistoryEntry {
@@ -82,6 +83,10 @@ Layout CalculateLayout(Arena *arena, Buffer &buffer, Font font, float font_size,
             row->columns.add({cell_rect, iter.pos, (int)iter.item});
             row->rect.max = cell_rect.max;
 
+            if (layout.max_column == NULL || row->rect.max.x > layout.max_column->rect.max.x) {
+                layout.max_column = row->columns.last();
+            }
+
             text_offset_x += x_to_offset_by;
         }
 
@@ -111,6 +116,10 @@ Layout CalculateLayout(Arena *arena, Buffer &buffer, Font font, float font_size,
         Rect2 cell_rect = {glyph_position, Vector2Add(glyph_position, cell_size)};
         row->columns.add({cell_rect, buffer.len, '\0'});
         row->rect = {glyph_position, cell_rect.max};
+
+        if (layout.max_column == NULL || row->rect.max.x > layout.max_column->rect.max.x) {
+            layout.max_column = row->columns.last();
+        }
     }
 
     layout.buffer_world_pixel_size.y = text_offset_y;
diff --git a/src/text_editor/main.cpp b/src/text_editor/main.cpp
index aa998c7..2605fd5 100644
--- a/src/text_editor/main.cpp
+++ b/src/text_editor/main.cpp
@@ -123,8 +123,6 @@ int main() {
 
             float mouse_wheel = GetMouseWheelMove() * 48;
             focused_window->scroll.y -= mouse_wheel;
-            focused_window->scroll.y = ClampBottom(focused_window->scroll.y, 0.f);
-            focused_window->scroll.x = ClampBottom(focused_window->scroll.x, 0.f);
 
             MergeCursors(focused_window);
             if (IsKeyDown(KEY_LEFT_CONTROL) && IsKeyPressed(KEY_A)) {
@@ -430,8 +428,8 @@ int main() {
                 DrawRectangleRec(ToRectangle(window.rect), WHITE);
 
                 Vec2 size = GetSize(window.rect);
-                Vec2 min  = window.scroll / window.layout.buffer_world_pixel_size;
-                Vec2 max  = (window.scroll + size) / window.layout.buffer_world_pixel_size;
+                Vec2 min  = window.scroll / (window.layout.buffer_world_pixel_size + size);
+                Vec2 max  = (window.scroll + size) / (window.layout.buffer_world_pixel_size + size);
 
                 DrawRectangleRec(ToRectangle(vertical_bar_rect), GRAY);
                 {
@@ -456,7 +454,6 @@ int main() {
                         }
                         float value = GetMouseDelta().y / vert_size;
                         window.scroll.y += value * window.layout.buffer_world_pixel_size.y;
-                        window.scroll.y = ClampBottom(window.scroll.y, 0.f);
                     }
                 }
 
@@ -483,11 +480,15 @@ int main() {
                         }
                         float value = GetMouseDelta().x / hori_size;
                         window.scroll.x += value * window.layout.buffer_world_pixel_size.x;
-                        window.scroll.x = ClampBottom(window.scroll.x, 0.f);
                     }
                 }
             }
 
+            {
+                window.scroll.y = Clamp(window.scroll.y, 0.f, window.layout.rows.last()->rect.min.y);
+                window.scroll.x = Clamp(window.scroll.x, 0.f, window.layout.max_column->rect.min.x);
+            }
+
             // Mouse selection
             if (!window.mouse_selecting_hori_bar && !window.mouse_selecting_vert_bar) {
                 bool mouse_in_window = CheckCollisionPointRec(mouse, ToRectangle(window.rect)) ||