banana

README

banana engine

banana engine is a 2d graphics engine.

currently supported

• basic shape rendering
• texture rendering
• rendering to a framebuffer
• input detection (keyboard and mouse)
• bitmap font

I'm currently researching strategies to implement a gui system.

Check out the examples dir...

drawing a triangle

go run ./examples/triangle

import (
	"github.com/dfirebaugh/banana"
	"golang.org/x/image/colornames"
)

const (
	screenWidth  = 240
	screenHeight = 160
)

func main() {
	banana.SetWindowSize(screenWidth, screenHeight)
	banana.Run(nil, func() {
		banana.Clear(colornames.Skyblue)
		banana.RenderShape(&banana.Polygon{
			Vertices: []banana.Vertex{
				{
					X:     0,
					Y:     float32(screenHeight),
					Color: colornames.Red,
				},
				{
					X:     float32(screenWidth / 2),
					Y:     0,
					Color: colornames.Green,
				},
				{
					X:     float32(screenWidth),
					Y:     float32(screenHeight),
					Color: colornames.Blue,
				},
			},
		})
	})
}

Documentation

Index

• func BindFramebuffer(fb graphics.Framebuffer)
• func Clear(c color.Color)
• func Close()
• func DisableFPS()
• func DisableWindowResize()
• func Draw()
• func EnableFPS()
• func GetCursorPosition() (int, int)
• func GetFPS() float64
• func GetViewportSize() (int, int)
• func GetWindowHeight() int
• func GetWindowPosition() (int, int)
• func GetWindowSize() (int, int)
• func GetWindowWidth() int
• func IsButtonJustPressed(buttonCode input.MouseButton) bool
• func IsButtonPressed(buttonCode input.MouseButton) bool
• func IsKeyJustPressed(keyCode input.Key) bool
• func IsKeyPressed(keyCode input.Key) bool
• func PressButton(buttonCode input.MouseButton)
• func PressKey(keyCode input.Key)
• func ReleaseButton(buttonCode input.MouseButton)
• func ReleaseKey(keyCode input.Key)
• func RenderFramebuffer(fb Framebuffer, options *TextureRenderOptions)
• func RenderShape(shape Renderable)
• func RenderText(text string, options *TextRenderOptions)
• func RenderTexture(textureHandle uint32, options *TextureRenderOptions)
• func ResizeFramebuffer(fb Framebuffer, width, height int)
• func Run(updateFn func(), renderFn func())
• func RunApp(game Game)
• func RunGame(game Game)
• func SetBorderlessWindowed(v bool)
• func SetFullScreenBorderless(v bool)
• func SetResizeCallback(fn func(physicalWidth, physicalHeight uint32))
• func SetScrollCallback(cb func(x float64, y float64))
• func SetTitle(title string)
• func SetWindowPosition(x, y int)
• func SetWindowSize(width, height int)
• func UnbindFramebuffer()
• func UpdateTexture(textureID uint32, img image.Image, xOffset, yOffset float32)
• func UploadTexture(img image.Image) uint32
• func Viewport(x int32, y int32, width int32, height int32)
• type Circle
  • func (c *Circle) GetVertices(screenWidth, screenHeight int) []graphics.Vertex
• type Framebuffer
  • func AddFramebuffer(width, height int) (Framebuffer, error)
• type Game
• type Polygon
  • func (t *Polygon) GetVertices(screenWidth, screenHeight int) []graphics.Vertex
• type Rect
  • func (r *Rect) GetVertices(screenWidth, screenHeight int) []graphics.Vertex
  • func (r *Rect) IsWithinBounds(px, py float32) bool
• type Renderable
• type Segment
  • func (l *Segment) GetStencilTestValue() uint8
  • func (l *Segment) GetStencilWriteValue() uint8
  • func (l *Segment) GetVertices(screenWidth, screenHeight int) []graphics.Vertex
• type TextRenderOptions
• type TextureRenderOptions
• type Vertex

Functions

func BindFramebuffer

func BindFramebuffer(fb graphics.Framebuffer)

func Clear

func Clear(c color.Color)

Clear clears the screen with the specified color.

func Close

func Close()

func DisableFPS

func DisableFPS()

DisableFPS disables the FPS counter in the window title.

func DisableWindowResize

func DisableWindowResize()

func Draw

func Draw()

func EnableFPS

func EnableFPS()

EnableFPS enables the FPS counter in the window title.

func GetCursorPosition

func GetCursorPosition() (int, int)

func GetFPS

func GetFPS() float64

func GetViewportSize

func GetViewportSize() (int, int)

func GetWindowHeight

func GetWindowHeight() int

func GetWindowPosition

func GetWindowPosition() (int, int)

func GetWindowSize

func GetWindowSize() (int, int)

GetWindowSize retrieves the current window size.

func GetWindowWidth

func GetWindowWidth() int

func IsButtonJustPressed

func IsButtonJustPressed(buttonCode input.MouseButton) bool

IsButtonJustPressed checks if a mouse button was just pressed

func IsButtonPressed

func IsButtonPressed(buttonCode input.MouseButton) bool

func IsKeyJustPressed

func IsKeyJustPressed(keyCode input.Key) bool

func IsKeyPressed

func IsKeyPressed(keyCode input.Key) bool

IsKeyPressed checks if a key is currently pressed

func PressButton

func PressButton(buttonCode input.MouseButton)

PressButton simulates a mouse button press

func PressKey

func PressKey(keyCode input.Key)

func ReleaseButton

func ReleaseButton(buttonCode input.MouseButton)

func ReleaseKey

func ReleaseKey(keyCode input.Key)

func RenderFramebuffer

func RenderFramebuffer(fb Framebuffer, options *TextureRenderOptions)

func RenderShape

func RenderShape(shape Renderable)

func RenderText

func RenderText(text string, options *TextRenderOptions)

func RenderTexture

func RenderTexture(textureHandle uint32, options *TextureRenderOptions)

func ResizeFramebuffer

func ResizeFramebuffer(fb Framebuffer, width, height int)

func Run

func Run(updateFn func(), renderFn func())

Run is the main update function called to refresh the engine state.

func RunApp

func RunApp(game Game)

func RunGame

func RunGame(game Game)

func SetBorderlessWindowed

func SetBorderlessWindowed(v bool)

func SetFullScreenBorderless

func SetFullScreenBorderless(v bool)

func SetResizeCallback

func SetResizeCallback(fn func(physicalWidth, physicalHeight uint32))

func SetScrollCallback

func SetScrollCallback(cb func(x float64, y float64))

func SetTitle

func SetTitle(title string)

SetTitle sets the title of the window.

func SetWindowPosition

func SetWindowPosition(x, y int)

func SetWindowSize

func SetWindowSize(width, height int)

func UnbindFramebuffer

func UnbindFramebuffer()

func UpdateTexture

func UpdateTexture(textureID uint32, img image.Image, xOffset, yOffset float32)

func UploadTexture

func UploadTexture(img image.Image) uint32

func Viewport

func Viewport(x int32, y int32, width int32, height int32)

Types

type Circle

type Circle struct {
	X, Y, Radius float32
	Color        color.Color
}

func (*Circle) GetVertices

func (c *Circle) GetVertices(screenWidth, screenHeight int) []graphics.Vertex

type Framebuffer

type Framebuffer graphics.Framebuffer

func AddFramebuffer

func AddFramebuffer(width, height int) (Framebuffer, error)

type Game

type Game interface {
	Update()
	Render()
}

type Polygon

type Polygon struct {
	Vertices []Vertex
}

func (*Polygon) GetVertices

func (t *Polygon) GetVertices(screenWidth, screenHeight int) []graphics.Vertex

type Rect

type Rect struct {
	X, Y, Width, Height, Radius float32
	Color                       color.Color
}

func (*Rect) GetVertices

func (r *Rect) GetVertices(screenWidth, screenHeight int) []graphics.Vertex

func (*Rect) IsWithinBounds

func (r *Rect) IsWithinBounds(px, py float32) bool

type Renderable

type Renderable interface {
	GetVertices(screenWidth, screenHeight int) []graphics.Vertex
}

type Segment

type Segment struct {
	X1, Y1, X2, Y2, Width float32
	Color                 color.Color
	StencilWriteValue     uint8
	StencilTestValue      uint8
}

func (*Segment) GetStencilTestValue

func (l *Segment) GetStencilTestValue() uint8

func (*Segment) GetStencilWriteValue

func (l *Segment) GetStencilWriteValue() uint8

func (*Segment) GetVertices

func (l *Segment) GetVertices(screenWidth, screenHeight int) []graphics.Vertex

type TextRenderOptions

type TextRenderOptions struct {
	X, Y, Size float32
	Color      color.Color
}

type TextureRenderOptions

type TextureRenderOptions struct {
	TextureIndex                int
	X, Y                        float32
	RectWidth, RectHeight       float32
	DesiredWidth, DesiredHeight float32
	Scale                       float32
	RectX, RectY                float32
	Width, Height               float32
	FlipX, FlipY                bool
	Rotation                    float32
}

type Vertex

type Vertex struct {
	X, Y  float32
	Color color.Color
}