# orx-camera

2D and 3D cameras controllable via mouse and keyboard.

## Usage

```kotlin
import org.openrndr.application
import org.openrndr.color.ColorRGBa
import org.openrndr.draw.DrawPrimitive
import org.openrndr.extra.camera.AxisHelper
import org.openrndr.extra.camera.GridHelper
import org.openrndr.extra.camera.OrbitalCamera
import org.openrndr.extra.camera.OrbitalControls
import org.openrndr.extra.meshgenerators.boxMesh
import org.openrndr.extra.meshgenerators.sphereMesh
import org.openrndr.math.Vector3

fun main() = application {
    program {
        val camera = OrbitalCamera(
            Vector3.UNIT_Z * 90.0, Vector3.ZERO, 90.0, 0.1, 5000.0
        )
        val controls = OrbitalControls(camera, keySpeed = 10.0)

        val sphere = sphereMesh(radius = 25.0)
        val cube = boxMesh(20.0, 20.0, 5.0, 5, 5, 2)

        extend(camera)
        extend(AxisHelper()) // shows XYZ axes as RGB lines
        extend(GridHelper(100)) // debug ground plane
        extend(controls) // adds both mouse and keyboard bindings
        extend {
            drawer.vertexBuffer(sphere, DrawPrimitive.LINE_LOOP)
            drawer.vertexBuffer(cube, DrawPrimitive.LINE_LOOP)
            drawer.stroke = ColorRGBa.WHITE
            drawer.fill = null
            repeat(10) {
                drawer.translate(0.0, 0.0, 10.0)
                // 2D primitives are not optimized for 3D and can
                // occlude each other
                drawer.circle(0.0, 0.0, 50.0)
            }
        }
    }
}
```

### Keybindings

* `w` - move forwards (+z)
* `s` - move backwards (-z)
* `Left` or `a` - strafe left (-x)
* `Right` or `d` - strafe right (+x)
* `Up` or `e`  -  move up (+y)
* `Down` or `q` -  move up (-y)
* `Page Up` -  zoom in
* `Page Down` -  zoom out
<!-- __demos__ -->
## Demos
### DemoCamera2D01

#### Camera2D demo

click and drag the mouse for panning, use the mouse wheel for zooming

![DemoCamera2D01Kt](https://raw.githubusercontent.com/openrndr/orx/media/orx-camera/images/DemoCamera2D01Kt.png)

[source code](src/jvmDemo/kotlin/DemoCamera2D01.kt)

### DemoCamera2D02

#### Camera2D demo with static elements

An approach for having certain elements not affected by the camera.
See DemoCamera2DManual01.kt for a new and simpler approach

![DemoCamera2D02Kt](https://raw.githubusercontent.com/openrndr/orx/media/orx-camera/images/DemoCamera2D02Kt.png)

[source code](src/jvmDemo/kotlin/DemoCamera2D02.kt)

### DemoCamera2DManual01

Demonstrates how to use `Camera2DManual` to have
some elements affected by an interactive 2D camera combined with
other elements not affected by it.

In this example both PINK circles can be dragged, scaled and rotated
while the white circle in the middle is static.

![DemoCamera2DManual01Kt](https://raw.githubusercontent.com/openrndr/orx/media/orx-camera/images/DemoCamera2DManual01Kt.png)

[source code](src/jvmDemo/kotlin/DemoCamera2DManual01.kt)

### DemoCamera2DManual02

Demonstrate the use of `Camera2DManual` to independently translate, scale and rotate one contour
in a collection.

When the mouse is clicked, the active contour is transformed using the camera view matrix,
then the camera is reset to its default state and whatever shape is under the mouse becomes
the new active contour.

As the mouse is dragged or its wheel scrolled, the camera is updated, affecting
how the active contour is rendered.

![DemoCamera2DManual02Kt](https://raw.githubusercontent.com/openrndr/orx/media/orx-camera/images/DemoCamera2DManual02Kt.png)

[source code](src/jvmDemo/kotlin/DemoCamera2DManual02.kt)

### DemoOrbital01

Demonstrate the use of `Orbital`, an interactive 3D camera
that can be controlled with a mouse and a keyboard.

![DemoOrbital01Kt](https://raw.githubusercontent.com/openrndr/orx/media/orx-camera/images/DemoOrbital01Kt.png)

[source code](src/jvmDemo/kotlin/DemoOrbital01.kt)

### DemoOrbitalCamera01

Demonstrate the use of `OrbitalCamera`, `OrbitalControls`, `AxisHelper` and `GridHelper`.

Press the `t` key to toggle camera interaction, or `r` to reset the camera to its defaults.

![DemoOrbitalCamera01Kt](https://raw.githubusercontent.com/openrndr/orx/media/orx-camera/images/DemoOrbitalCamera01Kt.png)

[source code](src/jvmDemo/kotlin/DemoOrbitalCamera01.kt)

### DemoOrbitalManual01

Demonstrate the use of an orbital camera to render a sphere and a cube in 3D space as wireframe meshes, positioned
and rendered independently using the camera's isolated drawing state. A stationary pink circle is also drawn in the
center of the scene.

Functionality:
- Initializes a sphere mesh and a cube mesh with predefined dimensions.
- Spawns an orbital camera, initially positioned away from the origin, to allow for focused rendering.
- Renders 3D wireframe shapes (sphere and cube) using the camera's isolated perspective.
- Draws a static 2D pink circle overlay at the window center.

![DemoOrbitalManual01Kt](https://raw.githubusercontent.com/openrndr/orx/media/orx-camera/images/DemoOrbitalManual01Kt.png)

[source code](src/jvmDemo/kotlin/DemoOrbitalManual01.kt)

### DemoParametricOrbital01

Demonstrates the use of a `ParametricOrbital` camera.
This 3D camera can't be directly interacted with a mouse or a keyboard,
but only via a GUI (or via code).

The GUI state is saved when closing the program and loaded
when running it again.

The GUI also allows randomizing, loading and saving
its state to a file via the top buttons it displays.

![DemoParametricOrbital01Kt](https://raw.githubusercontent.com/openrndr/orx/media/orx-camera/images/DemoParametricOrbital01Kt.png)

[source code](src/jvmDemo/kotlin/DemoParametricOrbital01.kt)