Package com.badlogic.gdx.graphics.g3d.model

Class MeshPart

  • public class MeshPart
extends java.lang.Object
    A MeshPart is composed of a subset of vertices of a Mesh, along with the primitive type. The vertices subset is described by an offset and size. When the mesh is indexed (which is when Mesh.getNumIndices() > 0), then the offset represents the offset in the indices array and size represents the number of indices. When the mesh isn't indexed, then the offset member represents the offset in the vertices array and the size member represents the number of vertices.

    In other words: Regardless whether the mesh is indexed or not, when primitiveType is not a strip, then size equals the number of primitives multiplied by the number of vertices per primitive. So if the MeshPart represents 4 triangles ( primitiveType is GL_TRIANGLES), then the size member is 12 (4 triangles * 3 vertices = 12 vertices total). Likewise, if the part represents 12 lines (primitiveType is GL_LINES), then the size is 24 (12 lines * 2 vertices = 24 vertices total).

    Note that some classes might require the mesh (part) to be indexed.

    The Mesh referenced by the mesh member must outlive the MeshPart. When the mesh is disposed, the MeshPart is unusable.

    • Field Detail

      • id

        public java.lang.String id
        Unique id within model, may be null. Will be ignored by equals(MeshPart)

      • offset

        public int offset
        The offset in the mesh to this part. If the mesh is indexed (Mesh.getNumIndices() > 0), this is the offset in the indices array, otherwise it is the offset in the vertices array.

      • size

        public int size
        The size (in total number of vertices) of this part in the mesh. When the mesh is indexed ( Mesh.getNumIndices() > 0), this is the number of indices, otherwise it is the number of vertices.

      • mesh

        public Mesh mesh
        The Mesh the part references, also stored in Model

      • center

        public final Vector3 center
        The offset to the center of the bounding box of the shape, only valid after the call to update().

      • halfExtents

        public final Vector3 halfExtents
        The location, relative to center, of the corner of the axis aligned bounding box of the shape. Or, in other words: half the dimensions of the bounding box of the shape, where Vector3.x is half the width, Vector3.y is half the height and Vector3.z is half the depth. Only valid after the call to update().

      • radius

        public float radius
        The radius relative to center of the bounding sphere of the shape, or negative if not calculated yet. This is the same as the length of the halfExtents member. See update().

    • Constructor Detail

      • MeshPart

        public MeshPart()
        Construct a new MeshPart, with null values. The MeshPart is unusable until you set all members.

      • MeshPart

        public MeshPart​(java.lang.String id,
                Mesh mesh,
                int offset,
                int size,
                int type)
        Construct a new MeshPart and set all its values.
        Parameters:
        id - The id of the new part, may be null.
        mesh - The mesh which holds all vertices and (optional) indices of this part.
        offset - The offset within the mesh to this part.
        size - The size (in total number of vertices) of the part.
        type - The primitive type of the part (e.g. GL_TRIANGLES, GL_LINE_STRIP, etc.).

      • MeshPart

        public MeshPart​(MeshPart copyFrom)
        Construct a new MeshPart which is an exact copy of the provided MeshPart.
        Parameters:
        copyFrom - The MeshPart to copy.

    • Method Detail

      • set

        public MeshPart set​(MeshPart other)
        Set this MeshPart to be a copy of the other MeshPart
        Parameters:
        other - The MeshPart from which to copy the values
        Returns:
        this MeshPart, for chaining

      • set

        public MeshPart set​(java.lang.String id,
                    Mesh mesh,
                    int offset,
                    int size,
                    int type)
        Set this MeshPart to given values, does not update() the bounding box values.
        Returns:
        this MeshPart, for chaining.

      • update

        public void update()
        Calculates and updates the center, halfExtents and radius values. This is considered a costly operation and should not be called frequently. All vertices (points) of the shape are traversed to calculate the maximum and minimum x, y and z coordinate of the shape. Note that MeshPart is not aware of any transformation that might be applied when rendering. It calculates the untransformed (not moved, not scaled, not rotated) values.

      • equals

        public boolean equals​(MeshPart other)
        Compares this MeshPart to the specified MeshPart and returns true if they both reference the same Mesh and the offset, size and primitiveType members are equal. The id member is ignored.
        Parameters:
        other - The other MeshPart to compare this MeshPart to.
        Returns:
        True when this MeshPart equals the other MeshPart (ignoring the id member), false otherwise.

      • equals

        public boolean equals​(java.lang.Object arg0)
        Overrides:
        equals in class java.lang.Object

      • render

        public void render​(ShaderProgram shader,
                   boolean autoBind)
        Renders the mesh part using the specified shader, must be called after ShaderProgram.bind().
        Parameters:
        shader - the shader to be used
        autoBind - overrides the autoBind member of the Mesh

      • render

        public void render​(ShaderProgram shader)
        Renders the mesh part using the specified shader, must be called after ShaderProgram.bind().
        Parameters:
        shader - the shader to be used