Extract grid UI operation planning

src/app_core/grid_ui.h

@@ -0,0 +1,145 @@
+#pragma once
+
+#include "foundation/result.h"
+
+#include <string>
+#include <string_view>
+#include <utility>
+
+namespace pp::app {
+
+enum class GridUiOperation {
+    request_heightmap_pick,
+    load_heightmap,
+    clear_heightmap,
+    reload_heightmap,
+    render_lightmap,
+    commit_heightmap,
+};
+
+struct GridUiPlan {
+    GridUiOperation operation = GridUiOperation::request_heightmap_pick;
+    std::string path;
+    int texture_resolution = 0;
+    int sample_count = 0;
+    bool opens_picker = false;
+    bool loads_heightmap = false;
+    bool clears_heightmap = false;
+    bool renders_lightmap = false;
+    bool commits_heightmap = false;
+    bool updates_preview = false;
+    bool updates_ground_opacity = false;
+    bool updates_shading_mode = false;
+    bool shows_unsupported_message = false;
+    bool shows_progress = false;
+    bool mutates_grid_state = false;
+};
+
+[[nodiscard]] inline pp::foundation::Status validate_grid_texture_resolution(int texture_resolution) noexcept
+{
+    if (texture_resolution <= 0 || texture_resolution > 16384) {
+        return pp::foundation::Status::out_of_range("grid texture resolution must be within 1..16384");
+    }
+
+    return pp::foundation::Status::success();
+}
+
+[[nodiscard]] inline pp::foundation::Status validate_grid_lightmap_samples(int sample_count) noexcept
+{
+    if (sample_count <= 0 || sample_count > 4096) {
+        return pp::foundation::Status::out_of_range("grid lightmap samples must be within 1..4096");
+    }
+
+    return pp::foundation::Status::success();
+}
+
+[[nodiscard]] inline constexpr GridUiPlan plan_grid_heightmap_pick() noexcept
+{
+    GridUiPlan plan;
+    plan.operation = GridUiOperation::request_heightmap_pick;
+    plan.opens_picker = true;
+    return plan;
+}
+
+[[nodiscard]] inline pp::foundation::Result<GridUiPlan> plan_grid_heightmap_load(std::string_view path)
+{
+    if (path.empty()) {
+        return pp::foundation::Result<GridUiPlan>::failure(
+            pp::foundation::Status::invalid_argument("heightmap path must not be empty"));
+    }
+
+    GridUiPlan plan;
+    plan.operation = GridUiOperation::load_heightmap;
+    plan.path = std::string(path);
+    plan.loads_heightmap = true;
+    plan.updates_preview = true;
+    plan.updates_ground_opacity = true;
+    plan.mutates_grid_state = true;
+    return pp::foundation::Result<GridUiPlan>::success(std::move(plan));
+}
+
+[[nodiscard]] inline constexpr GridUiPlan plan_grid_heightmap_clear(bool has_heightmap) noexcept
+{
+    GridUiPlan plan;
+    plan.operation = GridUiOperation::clear_heightmap;
+    plan.clears_heightmap = true;
+    plan.updates_preview = has_heightmap;
+    plan.mutates_grid_state = has_heightmap;
+    return plan;
+}
+
+[[nodiscard]] inline pp::foundation::Result<GridUiPlan> plan_grid_heightmap_reload(std::string_view path)
+{
+    auto plan = plan_grid_heightmap_load(path);
+    if (!plan) {
+        return pp::foundation::Result<GridUiPlan>::failure(plan.status());
+    }
+    plan.value().operation = GridUiOperation::reload_heightmap;
+    plan.value().updates_ground_opacity = false;
+    return plan;
+}
+
+[[nodiscard]] inline pp::foundation::Result<GridUiPlan> plan_grid_lightmap_render(
+    bool has_heightmap,
+    bool supports_float32,
+    bool supports_float16,
+    int texture_resolution,
+    int sample_count)
+{
+    const auto texture_status = validate_grid_texture_resolution(texture_resolution);
+    if (!texture_status.ok()) {
+        return pp::foundation::Result<GridUiPlan>::failure(texture_status);
+    }
+
+    const auto sample_status = validate_grid_lightmap_samples(sample_count);
+    if (!sample_status.ok()) {
+        return pp::foundation::Result<GridUiPlan>::failure(sample_status);
+    }
+
+    GridUiPlan plan;
+    plan.operation = GridUiOperation::render_lightmap;
+    plan.texture_resolution = texture_resolution;
+    plan.sample_count = sample_count;
+    if (!supports_float32 && !supports_float16) {
+        plan.shows_unsupported_message = true;
+        return pp::foundation::Result<GridUiPlan>::success(plan);
+    }
+
+    plan.renders_lightmap = has_heightmap;
+    plan.shows_progress = has_heightmap;
+    plan.updates_shading_mode = has_heightmap;
+    plan.mutates_grid_state = has_heightmap;
+    return pp::foundation::Result<GridUiPlan>::success(plan);
+}
+
+[[nodiscard]] inline constexpr GridUiPlan plan_grid_heightmap_commit(bool has_canvas) noexcept
+{
+    GridUiPlan plan;
+    plan.operation = GridUiOperation::commit_heightmap;
+    plan.commits_heightmap = has_canvas;
+    plan.updates_ground_opacity = has_canvas;
+    plan.mutates_grid_state = has_canvas;
+    return plan;
+}
+
+} // namespace pp::app