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o3de/Gems/LmbrCentral/Code/Source/Shape/ShapeGeometryUtil.h

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C++

/*
* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
* its licensors.
*
* For complete copyright and license terms please see the LICENSE at the root of this
* distribution (the "License"). All use of this software is governed by the License,
* or, if provided, by the license below or the license accompanying this file. Do not
* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
*/
#pragma once
#include <AzCore/Math/Vector2.h>
#include <AzCore/Math/Vector3.h>
namespace AzFramework
{
class DebugDisplayRequests;
}
namespace LmbrCentral
{
struct ShapeDrawParams;
/// Buffers used for rendering Shapes.
/// Generated from shape properties.
struct ShapeMesh
{
AZStd::vector<AZ::Vector3> m_vertexBuffer; ///< Vertices of the shape.
AZStd::vector<AZ::u32> m_indexBuffer; ///< Indices of the shape.
AZStd::vector<AZ::Vector3> m_lineBuffer; ///< Lines of the shape.
};
/// Writes 3 indices (1 tri) to the buffer and returns a pointer to the next index.
AZ::u32* WriteTriangle(AZ::u32 a, AZ::u32 b, AZ::u32 c, AZ::u32* indices);
/// Writes a vertex to the buffer and returns a pointer to the next vertex.
AZ::Vector3* WriteVertex(const AZ::Vector3& vertex, AZ::Vector3* vertices);
/// Draw a ShapeMesh (previously generated vertices, indices and lines).
void DrawShape(
AzFramework::DebugDisplayRequests& debugDisplay,
const ShapeDrawParams& shapeDrawParams, const ShapeMesh& shapeMesh);
/// Return a vector of vertices representing a list of triangles to render (CCW).
/// This is implemented using the Ear Clipping method:
/// (https://www.gamedev.net/articles/programming/graphics/polygon-triangulation-r3334/)
/// @param vertices List of vertices to process (pass by value as vertices is
/// modified inside the function so must be copied).
AZStd::vector<AZ::Vector3> GenerateTriangles(AZStd::vector<AZ::Vector2> vertices);
/// Determine if a list of ordered vertices have clockwise winding order.
/// http://blog.element84.com/polygon-winding.html
bool ClockwiseOrder(const AZStd::vector<AZ::Vector2>& vertices);
namespace CapsuleTubeUtil
{
/// Generates all indices, assumes index pointer is valid.
void GenerateSolidMeshIndices(
AZ::u32 sides, AZ::u32 segments, AZ::u32 capSegments, AZ::u32* indices);
/// Generate verts to be used when drawing triangles for the start cap.
AZ::Vector3* GenerateSolidStartCap(
const AZ::Vector3& localPosition, const AZ::Vector3& direction,
const AZ::Vector3& side, float radius, AZ::u32 sides, AZ::u32 capSegments, AZ::Vector3* vertices);
/// Generate verts to be used when drawing triangles for the end cap.
AZ::Vector3* GenerateSolidEndCap(
const AZ::Vector3& localPosition, const AZ::Vector3& direction,
const AZ::Vector3& side, float radius, AZ::u32 sides, AZ::u32 capSegments, AZ::Vector3* vertices);
/// Generate vertices to be used for a loop of a segment along a tube or capsule (for use with index buffer).
AZ::Vector3* GenerateSegmentVertices(
const AZ::Vector3& point,
const AZ::Vector3& axis,
const AZ::Vector3& normal,
float radius,
AZ::u32 sides,
AZ::Vector3* vertices);
/// Generate a circle/loop for a given segment along the capsule/tube - Produces a series of begin/end
/// line segments to draw in DrawLines.
AZ::Vector3* GenerateWireLoop(
const AZ::Vector3& localPosition, const AZ::Vector3& direction, const AZ::Vector3& side,
AZ::u32 sides, float radius, AZ::Vector3* vertices);
/// Generate a series of lines to be drawn, arcing around the end of a capsule/tube
/// Two arcs, one horizontal and one vertical, arcing 180 degrees of a sphere.
AZ::Vector3* GenerateWireCap(
const AZ::Vector3& localPosition, const AZ::Vector3& direction, const AZ::Vector3& side,
float radius, AZ::u32 capSegments, AZ::Vector3* vertices);
/// Given a position, forward axis, side axis and angle (radians), calculate
/// the position of a final point on a sphere by summing the rotation of those
/// two axis from their starting orientation.
AZ::Vector3 CalculatePositionOnSphere(
const AZ::Vector3& localPosition, const AZ::Vector3& forwardAxis, const AZ::Vector3& sideAxis,
float radius, float angle);
}
}