Plan stroke commit sequencing

src/paint_renderer/compositor.cpp

@@ -1445,6 +1445,55 @@ pp::foundation::Result<CanvasStrokeRasterizationPlan> plan_canvas_stroke_rasteri
     return pp::foundation::Result<CanvasStrokeRasterizationPlan>::success(plan);
 }
 
+CanvasStrokeCommitSequencePlan plan_canvas_stroke_commit_sequence(CanvasStrokeCommitRequest request) noexcept
+{
+    CanvasStrokeCommitSequencePlan plan;
+    plan.erase_mode = request.erase_mode;
+    plan.alpha_locked = request.alpha_locked;
+    plan.selection_mask_active = request.selection_mask_active;
+    plan.uses_dual_stroke = !request.erase_mode && request.dual_stroke_enabled;
+    plan.uses_pattern = !request.erase_mode && request.pattern_enabled;
+    plan.updates_layer_bounds = !request.alpha_locked;
+
+    auto append_step = [&plan](CanvasStrokeCommitStep step) noexcept {
+        if (plan.step_count >= plan.steps.size()) {
+            return;
+        }
+        plan.steps[plan.step_count] = step;
+        ++plan.step_count;
+    };
+    auto bind = [&plan](CanvasStrokeCommitTextureRole role, std::uint8_t slot) noexcept {
+        if (plan.texture_binding_count >= plan.texture_bindings.size()) {
+            return;
+        }
+        plan.texture_bindings[plan.texture_binding_count] = CanvasStrokeCommitTextureBindingPlan {
+            .role = role,
+            .slot = slot,
+        };
+        ++plan.texture_binding_count;
+    };
+
+    append_step(CanvasStrokeCommitStep::readback_history_region);
+    append_step(CanvasStrokeCommitStep::update_layer_dirty_state);
+    append_step(CanvasStrokeCommitStep::copy_layer_rtt_to_scratch);
+    append_step(CanvasStrokeCommitStep::bind_commit_inputs);
+    append_step(request.erase_mode ? CanvasStrokeCommitStep::erase_draw : CanvasStrokeCommitStep::composite_draw);
+    append_step(CanvasStrokeCommitStep::copy_committed_rtt_to_scratch);
+    append_step(CanvasStrokeCommitStep::dilate_edges_draw);
+
+    bind(CanvasStrokeCommitTextureRole::layer_scratch, 0);
+    bind(CanvasStrokeCommitTextureRole::stroke, 1);
+    bind(CanvasStrokeCommitTextureRole::selection_mask, 2);
+    if (plan.uses_dual_stroke) {
+        bind(CanvasStrokeCommitTextureRole::dual_stroke, 3);
+    }
+    if (plan.uses_pattern) {
+        bind(CanvasStrokeCommitTextureRole::pattern, 4);
+    }
+
+    return plan;
+}
+
 CanvasStrokeSampleBoundsPlan plan_canvas_stroke_sample_bounds(
     CanvasStrokeSampleBoundsRequest request) noexcept
 {