如何在不重新缩放整个节点的情况下在Sprite2D中缩放Urho3D？

Question

我想要缩放一个2D精灵，使其与节点的碰撞框一样大。

我只使用了Node::SetScale和一些手工标度计算，但我不想用这种方法做，因为它是复杂的，因为我也必须考虑到物理体的缩放因子。

但是，我无法为SetScale类找到一个StaticSprite2D方法。

关键代码部分是：

#if 0
        // Sprite and collision have the same size,
        // like I want it, but I feel this is very convoluted.
        auto rect = boxSprite->GetRectangle();
        auto scaleX = PIXEL_SIZE * rect.Width();
        auto scaleY = PIXEL_SIZE * rect.Height();
        node->SetScale(Vector3(groundWidth / scaleX, groundHeight / scaleY, 0.0f));
        shape->SetSize(Vector2(scaleX, scaleY));
#else
        // Collision shape is correct, but the sprite is smaller
        // so not what I want.
        shape->SetSize(Vector2(groundWidth, groundHeight));
#endif

下面的全部可运行代码，用以下样板进行测试：sprite.cpp和Urho3D @ 5e8a275：

#include <Urho3D/Core/CoreEvents.h>
#include <Urho3D/Core/Object.h>
#include <Urho3D/Engine/Application.h>
#include <Urho3D/Engine/Engine.h>
#include <Urho3D/Engine/EngineDefs.h>
#include <Urho3D/Graphics/Camera.h>
#include <Urho3D/Graphics/DebugRenderer.h>
#include <Urho3D/Graphics/Graphics.h>
#include <Urho3D/Graphics/Octree.h>
#include <Urho3D/Graphics/Renderer.h>
#include <Urho3D/Input/Input.h>
#include <Urho3D/Input/InputEvents.h>
#include <Urho3D/Physics/PhysicsEvents.h>
#include <Urho3D/Resource/ResourceCache.h>
#include <Urho3D/Scene/Scene.h>
#include <Urho3D/Scene/SceneEvents.h>
#include <Urho3D/Urho2D/CollisionBox2D.h>
#include <Urho3D/Urho2D/CollisionCircle2D.h>
#include <Urho3D/Urho2D/Drawable2D.h>
#include <Urho3D/Urho2D/PhysicsWorld2D.h>
#include <Urho3D/Urho2D/RigidBody2D.h>
#include <Urho3D/Urho2D/Sprite2D.h>
#include <Urho3D/Urho2D/StaticSprite2D.h>

using namespace Urho3D;

class Main : public Application {
    URHO3D_OBJECT(Main, Application);
public:
    Main(Context* context) : Application(context) {
    }
    virtual void Setup() override {
        engineParameters_[EP_FULL_SCREEN] = false;
    }
    void Start() {
        SubscribeToEvent(E_POSTRENDERUPDATE, URHO3D_HANDLER(Main, HandlePostRenderUpdate));
        this->scene_ = new Scene(this->context_);
        scene_->CreateComponent<Octree>();
        scene_->CreateComponent<DebugRenderer>();
        scene_->CreateComponent<PhysicsWorld2D>();
        auto physicsWorld = scene_->GetComponent<PhysicsWorld2D>();
        auto cameraNode_ = scene_->CreateChild("camera");
        cameraNode_->SetPosition(Vector3(0.0f, 0.0f, -1.0f));
        auto camera = cameraNode_->CreateComponent<Camera>();
        camera->SetOrthographic(true);
        camera->SetOrthoSize(4.0);
        auto graphics = GetSubsystem<Graphics>();
        auto renderer = GetSubsystem<Renderer>();
        SharedPtr<Viewport> viewport(new Viewport(context_, scene_, cameraNode_->GetComponent<Camera>()));
        renderer->SetViewport(0, viewport);
        auto cache = GetSubsystem<ResourceCache>();
        auto boxSprite = cache->GetResource<Sprite2D>("Urho2D/Box.png");

        auto groundWidth = 2.0;
        auto groundHeight = 2.0;
        auto node = this->scene_->CreateChild("ground");
        node->SetPosition(Vector3(0.0f, 0.0f, 0.0f));
        node->CreateComponent<RigidBody2D>();
        auto shape = node->CreateComponent<CollisionBox2D>();
#if 0
        // Sprite and collision have the same size,
        // like I want it, but I feel this is very convoluted.
        auto rect = boxSprite->GetRectangle();
        auto scaleX = PIXEL_SIZE * rect.Width();
        auto scaleY = PIXEL_SIZE * rect.Height();
        node->SetScale(Vector3(groundWidth / scaleX, groundHeight / scaleY, 0.0f));
        shape->SetSize(Vector2(scaleX, scaleY));
#else
        // Collision shape is correct, but the sprite is smaller
        // so not what I want.
        shape->SetSize(Vector2(groundWidth, groundHeight));
#endif
        auto staticSprite = node->CreateComponent<StaticSprite2D>();
        staticSprite->SetSprite(boxSprite);
    }
    void Stop() {}
private:
    SharedPtr<Scene> scene_;
    void HandlePostRenderUpdate(StringHash eventType, VariantMap& eventData) {
        auto physicsWorld = this->scene_->GetComponent<PhysicsWorld2D>();
        physicsWorld->DrawDebugGeometry();
    }
};

URHO3D_DEFINE_APPLICATION_MAIN(Main);

有趣的是，有一个SetScale用于Sprite类，据我在示例中所见，它用于3D场景中的UI。

超集:2D中任意着色器：

• https://discourse.urho3d.io/t/2d-lights-shaders-glow-shadows/251
• https://github.com/urho3d/Urho3D/issues/462

还询问：https://discourse.urho3d.io/t/how-to-scale-a-sprite2d-in-urho3d-without-rescaling-the-entire-node/3785/1

Answer 1

StaticSprite2D::SetDrawRect

这是我需要的方法，它设定了雪碧在世界坐标下的大小。

它所取的矩形是以原点为中心的，我们只需给出对象的长度，而忽略位置。

完整更新的工作代码出现在：sprite.cpp

主要内容如下：

void CreateBox(float x, float y, float width, float height) {
    auto node = this->scene->CreateChild("Box");
    node->SetPosition(Vector3(x, y, 0.0f));
    node->SetRotation(Quaternion(0.0f, 0.0f, 30.0f));
    auto box = node->CreateComponent<CollisionBox2D>();
    box->SetSize(Vector2(width, height));
    box->SetRestitution(0.8);
    box->SetFriction(0.5f);
    box->SetDensity(1.0f);
    auto body = node->CreateComponent<RigidBody2D>();
    body->SetBodyType(BT_DYNAMIC);
    auto staticSprite = node->CreateComponent<StaticSprite2D>();
    staticSprite->SetSprite(this->boxSprite);
    staticSprite->SetDrawRect(Rect(
        width / 2.0f,
        -height / 2.0f,
        -width / 2.0f,
        height / 2.0f
    ));
    staticSprite->SetUseDrawRect(true);
}

从以下网站了解：https://discourse.urho3d.io/t/how-to-scale-a-sprite2d-in-urho3d-without-rescaling-the-entire-node/3785/2