diff --git a/Cheat-Sheet.md b/Cheat-Sheet.md index 9c5dd0a..968a960 100644 --- a/Cheat-Sheet.md +++ b/Cheat-Sheet.md @@ -2,19 +2,79 @@ This cheat sheet describes the essential APIs that are commonly used. For the co # General -## `Run` +## `ebiten.Run` ```go func Run(f func(*Image) error, width, height int, scale float64, title string) error ``` -Run runs the game. `f` is a function which is called at every frame. The argument `(*Image)` is the render target that represents the screen. The screen size is based on the given values (`width` and `height`). +`Run` runs the game. `f` is a function which is called at every frame. The argument `(*Image)` is the render target that represents the screen. The screen size is based on the given values (`width` and `height`). Ebiten tries to call f 60 times a second. In other words, TPS (ticks per second) is 60. This is not related to framerate (display's refresh rate). f is not called when the window is in background by default. This setting is configurable with `SetRunnableInBackground`. -Run returns error when 1) OpenGL error happens, 2) audio error happens or 3) f returns error. In the case of 3), Run returns the same error. +`Run` returns error when 1) OpenGL error happens, 2) audio error happens or 3) f returns error. In the case of 3), `Run` returns the same error. Don't call Run twice or more in one process. +# Graphics + +## `ebiten.Image` + +```go +type Image struct { + // contains filtered or unexported fields +} +``` + +`Image` represents a rectangle set of pixels. The pixel format is alpha-premultiplied RGBA. `Image` implements [`image.Image`](https://golang.org/pkg/image/#Image). + +### `ebiten.NewImage` + +```go +func NewImage(width, height int, filter Filter) (*Image, error) +``` + +`NewImage` returns an empty image. `NewImage` always returns nil error (so you can ignore that). + +`filter` argument is just for backward compatibility. If you are not sure, specify `FilterDefault`. + +### `ebiten.NewImageFromImage` + +```go +func NewImageFromImage(source image.Image, filter Filter) (*Image, error) +``` + +`NewImageFromImage` creates a new image with the given image (source). `NewImageFromImage` always returns nil error. + +`filter` argument is just for backward compatibility. If you are not sure, specify FilterDefault. + +### `(*ebiten.Image).Clear` + +```go +func (i *Image) Clear() error +``` + +`Clear` resets the pixels of the image into 0. + +`Clear` always returns nil. + +### `(*ebiten.Image).Fill` + +```go +func (i *Image) Fill(clr color.Color) error +``` + +`Fill` fills the image with a solid color. + +`Fill` always returns nil. + +### `(*ebiten.Image).Size` + +```go +func (i *Image) Size() (width, height int) +``` + +`Size` returns the size of the image. +