geom

A lightweight geometry liberay with fluent API.

Maven

<dependency>
  <groupId>com.github.nickscha</groupId>
  <artifactId>geom</artifactId>
  <version>0.0.2</version>
</dependency>

The artifact is published under https://oss.sonatype.org

Supported Types

Class names are aligned with GLSL names.

Roadmap version 0.0.3

• Add cascading Transform (Transf) class for translating, scaling and rotating matrices based on their parent matrices.
• Enhance Javadocs

Requirements

• Java 8 or later

Examples

For more examples have a look at the src/test/resources/demo directory.

MVP (Model View Projection Matrix)

Vec3f myObjectPosInScene = Vec3f.of(3, 5, -2);
Mat4f rotationMatrix = myObjectPosInScene.rotationMatrix();
Mat4f modelMatrix = Mat4f.modelMatrix(myObjectPosInScene);
// The view matrix is functionally equivalent to a camera. It does the
// same thing as a model matrix, but it applies the same transformations
// equally to every object in the scene. Moving the whole world 5 units
// towards us is the same as if we had walked 5 units forwards.
Mat4f viewMatrix = Mat4f.viewMatrix(myObjectPosInScene, rotationMatrix);
// We shrink the model secene to the specified ratios and define that
// objects nearer than one and farther than ten gets clipped out.
Mat4f projectionMatrix = Mat4f.projectionMatrix(90, 1024 / 860, 1, 10);
// The object to render has been moved from model to view (aka world)
// space to the projection matrix (rectangle as the screen)
Mat4f mvpMatrix = Mat4f.mvpMatrix(modelMatrix, viewMatrix, projectionMatrix);

Look at

Imagine an object in your 3d scene which should look always to your camera.
Here we resolve the roatation matrix for the model…

Vec3f camera = Vec3f.of(0, 5, 5);
Vec3f modelToLookAtCamera = Vec3f.of(7, 7, 7);
Mat4f.lookAtMatrix(camera, modelToLookAtCamera, Vec3f.of(0, 1, 0));

Calculating Normals based on two vectors

In this demo we will calculate the normal vector based on two supplied vectors.

Vec3f one = Vec3f.of(1, 1, 1);
Vec3f two = Vec3f.of(-1, -1, -1);
Vec3f normalized = one.cross(two).normalize(); // Result is 0,0,0

Swizzling types

Geom provides swizzling for all types.

Vec2f res = Vec3f.of(1, 2, 1).mul(2).xy();
Mat4f res = Vec3f.of(6, 2, 1).scaleMatrix();

Serialization

Geom provides a general purpose serialization for all types.

byte[] data = Vec3f.of(1,2,3).toBytes();
Vec3f res = Vec3f.fromBytes(data);