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#ifndef MBGL_PAINT_PROPERTY
#define MBGL_PAINT_PROPERTY
#include <mbgl/style/class_dictionary.hpp>
#include <mbgl/style/property_parsing.hpp>
#include <mbgl/style/function.hpp>
#include <mbgl/style/property_transition.hpp>
#include <mbgl/style/style_cascade_parameters.hpp>
#include <mbgl/style/style_calculation_parameters.hpp>
#include <mbgl/util/interpolate.hpp>
#include <rapidjson/document.h>
#include <map>
namespace mbgl {
using JSVal = rapidjson::Value;
template <typename T, typename Result = T>
class PaintProperty {
public:
using Fn = Function<Result>;
PaintProperty(T fallbackValue_)
: fallbackValue(fallbackValue_),
value(fallbackValue_) {
values.emplace(ClassID::Fallback, Fn(fallbackValue));
}
PaintProperty(const PaintProperty& other)
: values(other.values),
transitions(other.transitions) {
}
void operator=(const PaintProperty& other) {
values = other.values;
transitions = other.transitions;
}
void parse(const char* name, const JSVal& layer) {
values.clear();
values.emplace(ClassID::Fallback, Fn(fallbackValue));
std::string transitionName = { name };
transitionName += "-transition";
for (auto it = layer.MemberBegin(); it != layer.MemberEnd(); ++it) {
const std::string paintName { it->name.GetString(), it->name.GetStringLength() };
if (paintName.compare(0, 5, "paint") != 0)
continue;
bool isClass = paintName.compare(0, 6, "paint.") == 0;
if (isClass && paintName.length() <= 6)
continue;
ClassID classID = isClass ? ClassDictionary::Get().lookup(paintName.substr(6)) : ClassID::Default;
if (it->value.HasMember(name)) {
auto v = parseProperty<Fn>(name, it->value[name]);
if (v) {
values.emplace(classID, *v);
}
}
if (it->value.HasMember(transitionName.c_str())) {
auto v = parseProperty<PropertyTransition>(name, it->value[transitionName.c_str()]);
if (v) {
transitions.emplace(classID, *v);
}
}
}
}
void cascade(const StyleCascadeParameters& parameters) {
Duration delay = *parameters.defaultTransition.delay;
Duration duration = *parameters.defaultTransition.duration;
for (auto classID : parameters.classes) {
if (values.find(classID) == values.end())
continue;
if (transitions.find(classID) != transitions.end()) {
const PropertyTransition& transition = transitions[classID];
if (transition.delay) delay = *transition.delay;
if (transition.duration) duration = *transition.duration;
}
cascaded = std::make_unique<CascadedValue>(std::move(cascaded),
parameters.now + delay,
parameters.now + delay + duration,
values.at(classID));
break;
}
assert(cascaded);
}
bool calculate(const StyleCalculationParameters& parameters) {
assert(cascaded);
value = cascaded->calculate(parameters);
return cascaded->prior.operator bool();
}
operator T() const { return value; }
T fallbackValue;
std::map<ClassID, Fn> values;
std::map<ClassID, PropertyTransition> transitions;
struct CascadedValue {
CascadedValue(std::unique_ptr<CascadedValue> prior_,
TimePoint begin_,
TimePoint end_,
Fn value_)
: prior(std::move(prior_)),
begin(begin_),
end(end_),
value(value_) {
}
Result calculate(const StyleCalculationParameters& parameters) {
Result final = value.evaluate(parameters);
if (!prior) {
// No prior value.
return final;
} else if (parameters.now >= end) {
// Transition from prior value is now complete.
prior.reset();
return final;
} else {
// Interpolate between recursively-calculated prior value and final.
float t = std::chrono::duration<float>(parameters.now - begin) / (end - begin);
return util::interpolate(prior->calculate(parameters), final, t);
}
}
std::unique_ptr<CascadedValue> prior;
TimePoint begin;
TimePoint end;
Fn value;
};
std::unique_ptr<CascadedValue> cascaded;
Result value;
};
}
#endif
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