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// SPDX-License-Identifier: Unlicense OR MIT
package app
import (
"errors"
"syscall/js"
"gioui.org/gpu"
"gioui.org/internal/gl"
)
type glContext struct {
ctx js.Value
cnv js.Value
}
func newContext(w *window) (*glContext, error) {
args := map[string]interface{}{
// Enable low latency rendering.
// See https://developers.google.com/web/updates/2019/05/desynchronized.
"desynchronized": true,
"preserveDrawingBuffer": true,
}
ctx := w.cnv.Call("getContext", "webgl2", args)
if ctx.IsNull() {
ctx = w.cnv.Call("getContext", "webgl", args)
}
if ctx.IsNull() {
return nil, errors.New("app: webgl is not supported")
}
c := &glContext{
ctx: ctx,
cnv: w.cnv,
}
return c, nil
}
func (c *glContext) RenderTarget() (gpu.RenderTarget, error) {
return gpu.OpenGLRenderTarget{}, nil
}
func (c *glContext) API() gpu.API {
return gpu.OpenGL{Context: gl.Context(c.ctx)}
}
func (c *glContext) Release() {
}
func (c *glContext) Present() error {
if c.ctx.Call("isContextLost").Bool() {
return errors.New("context lost")
}
return nil
}
func (c *glContext) Lock() error {
return nil
}
func (c *glContext) Unlock() {}
func (c *glContext) Refresh() error {
return nil
}
func (w *window) NewContext() (context, error) {
return newContext(w)
}
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