panels

ui/pipeline.sx

@@ -1,4 +1,5 @@
 #import "modules/std.sx";
+#import "modules/allocators.sx";
 #import "modules/opengl.sx";
 #import "ui/types.sx";
 #import "ui/render.sx";
@@ -15,12 +16,22 @@ UIPipeline :: struct {
     root: ViewChild;
     has_root: bool;
 
+    // Frame arena infrastructure
+    arena_a: Arena;
+    arena_b: Arena;
+    frame_index: s64;
+    body: Closure() -> View;
+    has_body: bool;
+    parent_allocator: Allocator;
+
     init :: (self: *UIPipeline, width: f32, height: f32) {
         self.render_tree = RenderTree.init();
         self.renderer.init();
         self.screen_width = width;
         self.screen_height = height;
         self.has_root = false;
+        self.has_body = false;
+        self.frame_index = 0;
     }
 
     init_font :: (self: *UIPipeline, path: [:0]u8, size: f32, dpi_scale: f32) {
@@ -35,6 +46,16 @@ UIPipeline :: struct {
         self.has_root = true;
     }
 
+    set_body :: (self: *UIPipeline, body_fn: Closure() -> View) {
+        self.body = body_fn;
+        self.has_body = true;
+        self.parent_allocator = context.allocator;
+        // Initialize both arenas (256KB initial, grows automatically)
+        self.arena_a.create(self.parent_allocator, 262144);
+        self.arena_b.create(self.parent_allocator, 262144);
+        self.frame_index = 0;
+    }
+
     resize :: (self: *UIPipeline, width: f32, height: f32) {
         self.screen_width = width;
         self.screen_height = height;
@@ -48,9 +69,12 @@ UIPipeline :: struct {
 
     // Run one frame: layout → render → commit
     tick :: (self: *UIPipeline) {
+        if self.has_body {
+            self.tick_with_body();
+            return;
+        }
         if self.has_root == false { return; }
 
-        screen := Frame.make(0.0, 0.0, self.screen_width, self.screen_height);
         proposal := ProposedSize.fixed(self.screen_width, self.screen_height);
 
         // Layout
@@ -67,11 +91,49 @@ UIPipeline :: struct {
         self.root.view.render(@ctx, self.root.computed_frame);
 
         // Commit to GPU
+        self.commit_gpu();
+    }
+
+    tick_with_body :: (self: *UIPipeline) {
+        build_arena : *Arena = if self.frame_index & 1 == 0 then @self.arena_a else @self.arena_b;
+        build_arena.reset();
+
+        // Reset render_tree nodes (backing is stale after arena reset)
+        self.render_tree.nodes.items = xx 0;
+        self.render_tree.nodes.len = 0;
+        self.render_tree.nodes.cap = 0;
+
+        push Context.{ allocator = xx build_arena, data = context.data } {
+            // Workaround: self.body() crashes through struct field (issue-0010)
+            body_fn := self.body;
+            root_view := body_fn();
+            self.root = ViewChild.{ view = root_view };
+            self.has_root = true;
+
+            proposal := ProposedSize.fixed(self.screen_width, self.screen_height);
+            root_size := self.root.view.size_that_fits(proposal);
+            self.root.computed_frame = Frame.{
+                origin = Point.zero(),
+                size = root_size
+            };
+            self.root.view.layout(self.root.computed_frame);
+
+            self.render_tree.clear();
+            ctx := RenderContext.init(@self.render_tree);
+            self.root.view.render(@ctx, self.root.computed_frame);
+
+            self.commit_gpu();
+        }
+
+        self.frame_index += 1;
+    }
+
+    commit_gpu :: (self: *UIPipeline) {
         glEnable(GL_BLEND);
         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
         glDisable(GL_DEPTH_TEST);
 
-        self.renderer.begin(self.screen_width, self.screen_height);
+        self.renderer.begin(self.screen_width, self.screen_height, self.font.texture_id);
         self.renderer.process(@self.render_tree);
         self.renderer.flush();