Support floating-point animation frame numbers

irr/include/IAnimatedMesh.h

@@ -19,11 +19,8 @@ irr::scene::SMeshBuffer etc. */
 class IAnimatedMesh : public IMesh
 {
 public:
-	//! Gets the frame count of the animated mesh.
-	/** Note that the play-time is usually getFrameCount()-1 as it stops as soon as the last frame-key is reached.
-	\return The amount of frames. If the amount is 1,
-	it is a static, non animated mesh. 	*/
-	virtual u32 getFrameCount() const = 0;
+	//! Gets the maximum frame number, 0 if the mesh is static.
+	virtual f32 getMaxFrameNumber() const = 0;
 
 	//! Gets the animation speed of the animated mesh.
 	/** \return The number of frames per second to play the
@@ -39,19 +36,10 @@ public:
 	virtual void setAnimationSpeed(f32 fps) = 0;
 
 	//! Returns the IMesh interface for a frame.
-	/** \param frame: Frame number as zero based index. The maximum
-	frame number is getFrameCount() - 1;
-	\param detailLevel: Level of detail. 0 is the lowest, 255 the
-	highest level of detail. Most meshes will ignore the detail level.
-	\param startFrameLoop: Because some animated meshes (.MD2) are
-	blended between 2 static frames, and maybe animated in a loop,
-	the startFrameLoop and the endFrameLoop have to be defined, to
-	prevent the animation to be blended between frames which are
-	outside of this loop.
-	If startFrameLoop and endFrameLoop are both -1, they are ignored.
-	\param endFrameLoop: see startFrameLoop.
-	\return Returns the animated mesh based on a detail level. */
-	virtual IMesh *getMesh(s32 frame, s32 detailLevel = 255, s32 startFrameLoop = -1, s32 endFrameLoop = -1) = 0;
+	/** \param frame: Frame number, >= 0, <= getMaxFrameNumber()
+	Linear interpolation is used if this is between two frames.
+	\return Returns the animated mesh for the given frame */
+	virtual IMesh *getMesh(f32 frame) = 0;
 
 	//! Returns the type of the animated mesh.
 	/** In most cases it is not necessary to use this method.

irr/include/IAnimatedMeshSceneNode.h

@@ -63,7 +63,7 @@ public:
 	virtual void setCurrentFrame(f32 frame) = 0;
 
 	//! Sets the frame numbers between the animation is looped.
-	/** The default is 0 to getFrameCount()-1 of the mesh.
+	/** The default is 0 to getMaxFrameNumber() of the mesh.
 	Number of played frames is end-start.
 	It interpolates toward the last frame but stops when it is reached.
 	It does not interpolate back to start even when looping.
@@ -71,7 +71,7 @@ public:
 	\param begin: Start frame number of the loop.
 	\param end: End frame number of the loop.
 	\return True if successful, false if not. */
-	virtual bool setFrameLoop(s32 begin, s32 end) = 0;
+	virtual bool setFrameLoop(f32 begin, f32 end) = 0;
 
 	//! Sets the speed with which the animation is played.
 	/** \param framesPerSecond: Frames per second played. */
@@ -108,9 +108,9 @@ public:
 	//! Returns the currently displayed frame number.
 	virtual f32 getFrameNr() const = 0;
 	//! Returns the current start frame number.
-	virtual s32 getStartFrame() const = 0;
+	virtual f32 getStartFrame() const = 0;
 	//! Returns the current end frame number.
-	virtual s32 getEndFrame() const = 0;
+	virtual f32 getEndFrame() const = 0;
 
 	//! Sets looping mode which is on by default.
 	/** If set to false, animations will not be played looped. */

irr/include/SAnimatedMesh.h

@@ -36,11 +36,9 @@ struct SAnimatedMesh final : public IAnimatedMesh
 			mesh->drop();
 	}
 
-	//! Gets the frame count of the animated mesh.
-	/** \return Amount of frames. If the amount is 1, it is a static, non animated mesh. */
-	u32 getFrameCount() const override
+	f32 getMaxFrameNumber() const override
 	{
-		return static_cast<u32>(Meshes.size());
+		return static_cast<f32>(Meshes.size() - 1);
 	}
 
 	//! Gets the default animation speed of the animated mesh.
@@ -59,19 +57,14 @@ struct SAnimatedMesh final : public IAnimatedMesh
 	}
 
 	//! Returns the IMesh interface for a frame.
-	/** \param frame: Frame number as zero based index. The maximum frame number is
-	getFrameCount() - 1;
-	\param detailLevel: Level of detail. 0 is the lowest,
-	255 the highest level of detail. Most meshes will ignore the detail level.
-	\param startFrameLoop: start frame
-	\param endFrameLoop: end frame
-	\return The animated mesh based on a detail level. */
-	IMesh *getMesh(s32 frame, s32 detailLevel = 255, s32 startFrameLoop = -1, s32 endFrameLoop = -1) override
+	/** \param frame: Frame number as zero based index.
+	\return The animated mesh based for the given frame */
+	IMesh *getMesh(f32 frame) override
 	{
 		if (Meshes.empty())
-			return 0;
+			return nullptr;
 
-		return Meshes[frame];
+		return Meshes[static_cast<s32>(frame)];
 	}
 
 	//! adds a Mesh

irr/include/vector2d.h

@@ -38,6 +38,12 @@ public:
 	explicit constexpr vector2d(const std::array<T, 2> &arr) :
 			X(arr[0]), Y(arr[1]) {}
 
+	template <class U>
+	constexpr static vector2d<T> from(const vector2d<U> &other)
+	{
+		return {static_cast<T>(other.X), static_cast<T>(other.Y)};
+	}
+
 	// operators
 
 	vector2d<T> operator-() const { return vector2d<T>(-X, -Y); }