Greatly simplify view offset handling

Fixes https://github.com/ifreund/river/issues/9

6 files changed, 83 insertions, 81 deletions

diff --git a/src/box.zig b/src/box.zig
index 5d33f98..2d28a1c 100644
--- a/src/box.zig
+++ b/src/box.zig
@@ -1,6 +1,17 @@
-pub const Box = struct {
-    x: i32,
-    y: i32,
-    width: u32,
-    height: u32,
-};
+const Self = @This();
+
+const c = @import("c.zig");
+
+x: i32,
+y: i32,
+width: u32,
+height: u32,
+
+pub fn toWlrBox(self: Self) c.wlr_box {
+    return c.wlr_box{
+        .x = @intCast(c_int, self.x),
+        .y = @intCast(c_int, self.y),
+        .width = @intCast(c_int, self.width),
+        .height = @intCast(c_int, self.height),
+    };
+}
diff --git a/src/layer_surface.zig b/src/layer_surface.zig
index 38af53a..105eaad 100644
--- a/src/layer_surface.zig
+++ b/src/layer_surface.zig
@@ -1,7 +1,7 @@
 const std = @import("std");
 const c = @import("c.zig");
 
-const Box = @import("box.zig").Box;
+const Box = @import("box.zig");
 const Log = @import("log.zig").Log;
 const Output = @import("output.zig").Output;
 
diff --git a/src/output.zig b/src/output.zig
index 59b43dd..be762c6 100644
--- a/src/output.zig
+++ b/src/output.zig
@@ -2,7 +2,7 @@ const std = @import("std");
 const c = @import("c.zig");
 const render = @import("render.zig");
 
-const Box = @import("box.zig").Box;
+const Box = @import("box.zig");
 const LayerSurface = @import("layer_surface.zig").LayerSurface;
 const Log = @import("log.zig").Log;
 const Root = @import("root.zig").Root;
@@ -160,6 +160,8 @@ pub const Output = struct {
         const master_count = std.math.min(self.master_count, visible_count);
         const slave_count = if (master_count >= visible_count) 0 else visible_count - master_count;
 
+        const border_width = self.root.server.config.border_width;
+        const view_padding = self.root.server.config.view_padding;
         const outer_padding = self.root.server.config.outer_padding;
 
         const layout_width = @intCast(u32, self.usable_box.width) - outer_padding * 2;
@@ -183,30 +185,34 @@ pub const Output = struct {
         var it = ViewStack(View).pendingIterator(self.views.first, output_tags);
         while (it.next()) |node| {
             const view = &node.view;
+
             if (view.floating) {
                 continue;
             }
+
+            var new_box: Box = undefined;
+
+            // Add the remainder to the first master/slave to ensure every
+            // pixel of height is used
             if (i < master_count) {
-                // Add the remainder to the first master to ensure every pixel of height is used
                 const master_height = @divTrunc(layout_height, master_count);
                 const master_height_rem = layout_height % master_count;
 
-                view.pending_box = Box{
-                    .x = @intCast(i32, outer_padding),
-                    .y = @intCast(i32, outer_padding + i * master_height +
+                new_box = .{
+                    .x = 0,
+                    .y = @intCast(i32, i * master_height +
                         if (i > 0) master_height_rem else 0),
 
                     .width = master_column_width,
                     .height = master_height + if (i == 0) master_height_rem else 0,
                 };
             } else {
-                // Add the remainder to the first slave to ensure every pixel of height is used
                 const slave_height = @divTrunc(layout_height, slave_count);
                 const slave_height_rem = layout_height % slave_count;
 
-                view.pending_box = Box{
-                    .x = @intCast(i32, outer_padding + master_column_width),
-                    .y = @intCast(i32, outer_padding + (i - master_count) * slave_height +
+                new_box = .{
+                    .x = @intCast(i32, master_column_width),
+                    .y = @intCast(i32, (i - master_count) * slave_height +
                         if (i > master_count) slave_height_rem else 0),
 
                     .width = slave_column_width,
@@ -215,6 +221,16 @@ pub const Output = struct {
                 };
             }
 
+            // Apply offsets from borders and padding
+            new_box.x += @intCast(i32, border_width + outer_padding + view_padding);
+            new_box.y += @intCast(i32, border_width + outer_padding + view_padding);
+
+            new_box.width -= (border_width + view_padding) * 2;
+            new_box.height -= (border_width + view_padding) * 2;
+
+            // Set the view's pending box to the new dimensions
+            view.pending_box = new_box;
+
             i += 1;
         }
     }
diff --git a/src/render.zig b/src/render.zig
index 9c4ab43..2e4dba6 100644
--- a/src/render.zig
+++ b/src/render.zig
@@ -1,6 +1,7 @@
 const std = @import("std");
 const c = @import("c.zig");
 
+const Box = @import("box.zig");
 const LayerSurface = @import("layer_surface.zig").LayerSurface;
 const Output = @import("output.zig").Output;
 const Server = @import("server.zig").Server;
@@ -168,13 +169,11 @@ fn renderView(output: Output, view: *View, now: *c.timespec) void {
     // If we have a stashed buffer, we are in the middle of a transaction
     // and need to render that buffer until the transaction is complete.
     if (view.stashed_buffer) |buffer| {
-        const border_width = view.output.root.server.config.border_width;
-        const view_padding = view.output.root.server.config.view_padding;
         var box = c.wlr_box{
-            .x = view.current_box.x + @intCast(i32, border_width + view_padding),
-            .y = view.current_box.y + @intCast(i32, border_width + view_padding),
-            .width = @intCast(c_int, view.current_box.width - border_width * 2 - view_padding * 2),
-            .height = @intCast(c_int, view.current_box.height - border_width * 2 - view_padding * 2),
+            .x = view.current_box.x,
+            .y = view.current_box.y,
+            .width = @intCast(c_int, view.current_box.width),
+            .height = @intCast(c_int, view.current_box.height),
         };
 
         // Scale the box to the output's current scaling factor
@@ -229,11 +228,9 @@ fn renderSurface(_surface: ?*c.wlr_surface, sx: c_int, sy: c_int, data: ?*c_void
         return;
     }
 
-    const border_width = view.output.root.server.config.border_width;
-    const view_padding = view.output.root.server.config.view_padding;
     var box = c.wlr_box{
-        .x = view.current_box.x + sx + @intCast(c_int, border_width + view_padding),
-        .y = view.current_box.y + sy + @intCast(c_int, border_width + view_padding),
+        .x = view.current_box.x + sx,
+        .y = view.current_box.y + sy,
         .width = surface.current.width,
         .height = surface.current.height,
     };
@@ -259,66 +256,46 @@ fn renderSurface(_surface: ?*c.wlr_surface, sx: c_int, sy: c_int, data: ?*c_void
 }
 
 fn renderBorders(output: Output, view: *View, now: *c.timespec) void {
-    var border: c.wlr_box = undefined;
+    var border: Box = undefined;
     const color = if (view.focused)
         [_]f32{ 0.57647059, 0.63137255, 0.63137255, 1.0 } // Solarized base1
     else
         [_]f32{ 0.34509804, 0.43137255, 0.45882353, 1.0 }; // Solarized base01
     const border_width = output.root.server.config.border_width;
-    const view_padding = output.root.server.config.view_padding;
-
-    // left border
-    border.x = view.current_box.x + @intCast(c_int, view_padding);
-    border.y = view.current_box.y + @intCast(c_int, view_padding);
-    border.width = @intCast(c_int, border_width);
-    border.height = @intCast(c_int, view.current_box.height - view_padding * 2);
-    scaleBox(&border, output.wlr_output.scale);
-    c.wlr_render_rect(
-        output.root.server.wlr_renderer,
-        &border,
-        &color,
-        &output.wlr_output.transform_matrix,
-    );
 
-    // right border
-    border.x = view.current_box.x +
-        @intCast(c_int, view.current_box.width - border_width - view_padding);
-    border.y = view.current_box.y + @intCast(c_int, view_padding);
-    border.width = @intCast(c_int, border_width);
-    border.height = @intCast(c_int, view.current_box.height - view_padding * 2);
-    scaleBox(&border, output.wlr_output.scale);
-    c.wlr_render_rect(
-        output.root.server.wlr_renderer,
-        &border,
-        &color,
-        &output.wlr_output.transform_matrix,
-    );
+    // left and right, covering the corners as well
+    border.y = view.current_box.y - @intCast(i32, border_width);
+    border.width = border_width;
+    border.height = view.current_box.height + border_width * 2;
 
-    // top border
-    border.x = view.current_box.x + @intCast(c_int, border_width + view_padding);
-    border.y = view.current_box.y + @intCast(c_int, view_padding);
-    border.width = @intCast(c_int, view.current_box.width -
-        border_width * 2 - view_padding * 2);
-    border.height = @intCast(c_int, border_width);
-    scaleBox(&border, output.wlr_output.scale);
-    c.wlr_render_rect(
-        output.root.server.wlr_renderer,
-        &border,
-        &color,
-        &output.wlr_output.transform_matrix,
-    );
+    // left
+    border.x = view.current_box.x - @intCast(i32, border_width);
+    renderRect(output, border, color);
+
+    // right
+    border.x = view.current_box.x + @intCast(i32, view.current_box.width);
+    renderRect(output, border, color);
+
+    // top and bottom
+    border.x = view.current_box.x;
+    border.width = view.current_box.width;
+    border.height = border_width;
+
+    // top
+    border.y = view.current_box.y - @intCast(i32, border_width);
+    renderRect(output, border, color);
 
     // bottom border
-    border.x = view.current_box.x + @intCast(c_int, border_width + view_padding);
-    border.y = view.current_box.y +
-        @intCast(c_int, view.current_box.height - border_width - view_padding);
-    border.width = @intCast(c_int, view.current_box.width -
-        border_width * 2 - view_padding * 2);
-    border.height = @intCast(c_int, border_width);
-    scaleBox(&border, output.wlr_output.scale);
+    border.y = view.current_box.y + @intCast(i32, view.current_box.height);
+    renderRect(output, border, color);
+}
+
+fn renderRect(output: Output, box: Box, color: [4]f32) void {
+    var wlr_box = box.toWlrBox();
+    scaleBox(&wlr_box, output.wlr_output.scale);
     c.wlr_render_rect(
         output.root.server.wlr_renderer,
-        &border,
+        &wlr_box,
         &color,
         &output.wlr_output.transform_matrix,
     );
diff --git a/src/view.zig b/src/view.zig
index 19614d0..a4ede46 100644
--- a/src/view.zig
+++ b/src/view.zig
@@ -1,7 +1,7 @@
 const std = @import("std");
 const c = @import("c.zig");
 
-const Box = @import("box.zig").Box;
+const Box = @import("box.zig");
 const Log = @import("log.zig").Log;
 const Output = @import("output.zig").Output;
 const Root = @import("root.zig").Root;
diff --git a/src/xdg_toplevel.zig b/src/xdg_toplevel.zig
index 4e7115a..0e64396 100644
--- a/src/xdg_toplevel.zig
+++ b/src/xdg_toplevel.zig
@@ -3,7 +3,7 @@ const Self = @This();
 const c = @import("c.zig");
 const std = @import("std");
 
-const Box = @import("box.zig").Box;
+const Box = @import("box.zig");
 const Log = @import("log.zig").Log;
 const View = @import("view.zig").View;
 const ViewStack = @import("view_stack.zig").ViewStack;
@@ -44,12 +44,10 @@ pub fn init(self: *Self, view: *View, wlr_xdg_surface: *c.wlr_xdg_surface) void
 }
 
 pub fn configure(self: Self, pending_box: Box) void {
-    const border_width = self.view.output.root.server.config.border_width;
-    const view_padding = self.view.output.root.server.config.view_padding;
     self.view.pending_serial = c.wlr_xdg_toplevel_set_size(
         self.wlr_xdg_surface,
-        pending_box.width - border_width * 2 - view_padding * 2,
-        pending_box.height - border_width * 2 - view_padding * 2,
+        pending_box.width,
+        pending_box.height,
     );
 }