doodle/pkg/shmem/globals.go
Noah Petherbridge ba6892aa95 WASM Texture Caching
* Refactor texture caching in render.Engine:
  * New interface method: NewTexture(filename string, image.Image)
  * WASM immediately encodes the image to PNG and generates a JavaScript
    `Image()` object to load it with a data URI and keep it in memory.
  * SDL2 saves the bitmap to disk as it did before.
  * WASM: deprecate the sessionStorage for holding image data. Session
    storage methods panic if called. The image data is directly kept in
    Go memory as a js.Value holding an Image().
* Shared Memory workaround: the level.Chunk.ToBitmap() function is where
  chunk textures get cached, but it had no access to the render.Engine
  used in the game. The `pkg/shmem` package holds global pointers to
  common structures like the CurrentRenderEngine as a work-around.
  * Also shmem.Flash() so Doodle can make its d.Flash() function
    globally available, any sub-package can now flash text to the screen
    regardless of source code location.
  * JavaScript API for Doodads now has a global Flash() function
    available.
* WASM: Handle window resize so Doodle can recompute its dimensions
  instead of scaling/shrinking the view.
2019-06-27 12:03:52 -07:00

27 lines
678 B
Go

package shmem
import (
"fmt"
"git.kirsle.net/apps/doodle/lib/render"
)
// Shared globals for easy access throughout the app.
// Not an ideal place to keep things but *shrug*
var (
// Current render engine (i.e. SDL2 or HTML5 Canvas)
// The level.Chunk.ToBitmap() uses this to cache a texture image.
CurrentRenderEngine render.Engine
// Globally available Flash() function so we can emit text to the Doodle UI.
Flash func(string, ...interface{})
)
func init() {
// Default Flash function in case the app misconfigures it. Output to the
// console in an obvious way.
Flash = func(tmpl string, v ...interface{}) {
fmt.Printf("[shmem.Flash] "+tmpl+"\n", v...)
}
}