README
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Atlas
A small package providing an Atlas type as well as atlas.Image which can be used for more control over batching draw calls.
It works by alleviating some generic work done by ebitengine when treating DrawImage commands.
Here, since the images are just regions of an atlas image, the commands can be converted to a slice of triangles that can be submitted in a single ebitengine command, relieving ebitengine from doing additional unnecessary work.
Originally made to address this: https://github.com/hajimehoshi/ebiten/issues/2976
Usage
go get github.com/Zyko0/Ebiary/atlas
- Empty atlas
// Create an atlas
atlas := atlas.New(1024, 1024, nil)
// Allocate an image on the atlas at a random location
img := app.atlas.NewImage(48, 48)
// Access the *ebiten.Image as a sub-image and set its content
img.Image().Fill(color.White)
- Atlas from spritesheet
// Create an atlas
atlas := atlas.New(1024, 1024, nil)
// Set the atlas image's content with the spritesheet image content
atlas.Image().DrawImage(spriteSheet, nil)
// Locate the sprite sub images on the atlas manually
img := app.atlas.SubImage(image.Rect(0,0,48,48))
- DrawList
// It's best to re-use the DrawList as Flush() clears the triangles
// but keeps the capacities for next Add commands
dl := &atlas.DrawList{}
dc := &atlas.DrawCommand{}
for _, s := range sprites {
dc.Image = s.Image
dc.GeoM = s.GeoM
dl.Add(dc)
}
// Flush all draws to the screen
dl.Flush(screen, nil)
An example can be found in examples/usage/main.go
Notes
- The
Text*related stuff is not implemented properly and will probably never work, since I realized we lack context fromtext/v2to cache all the variations of a glyphs. This results in a drawn text but some characters will have an incorrect X offset.
Documentation
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Index ¶
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type Atlas ¶
type Atlas struct {
// contains filtered or unexported fields
}
Atlas is a minimal write-only container for sub-images, that can be used with a DrawList to batch draw commands as triangles.
func New ¶
func New(width, height int, opts *NewAtlasOptions) *Atlas
type DrawCommand ¶
type DrawCommand struct {
Image *Image
ColorScale ebiten.ColorScale
GeoM ebiten.GeoM
}
DrawCommand is the equivalent of the regular DrawImageOptions but only including options that will not break batching. Filter, Address, Blend and AntiAlias are determined at Flush()
type DrawList ¶
type DrawList struct {
// contains filtered or unexported fields
}
DrawList stores triangle versions of DrawImage calls when all images are sub-images of an atlas. Temporary vertices and indices can be re-used after calling Flush, so it is more efficient to keep a reference to a DrawList instead of creating a new one every frame.
func (*DrawList) Add ¶
func (dl *DrawList) Add(commands ...*DrawCommand)
Add adds DrawImage commands to the DrawList, images from multiple atlases can be added but they will break the previous batch bound to a different atlas, requiring an additional draw call internally. So, it is better to have the maximum of consecutive DrawCommand images sharing the same atlas.
func (*DrawList) Flush ¶
func (dl *DrawList) Flush(dst *ebiten.Image, opts *DrawOptions)
Flush executes all the draw commands as the smallest possible amount of draw calls, and then clears the list for next uses.
type DrawOptions ¶
type DrawOptions struct {
ColorScaleMode ebiten.ColorScaleMode
Blend ebiten.Blend
Filter ebiten.Filter
Address ebiten.Address
AntiAlias bool
}
DrawOptions are additional options that will be applied to all draw commands from the draw list when calling Flush().
type Image ¶
type Image struct {
// contains filtered or unexported fields
}
Source Files
Directories