1 files changed, 69 insertions, 0 deletions
diff --git a/vendor/gioui.org/app/gl_js.go b/vendor/gioui.org/app/gl_js.go
new file mode 100644
index 0000000..e3aee8d
--- /dev/null
+++ b/vendor/gioui.org/app/gl_js.go
@@ -0,0 +1,69 @@
+// 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)
+}