graphics_state.go RawHistoryFolder

1package vt
2
3import (
4	"github.com/bnema/vev-vt/graphics"
5	"github.com/bnema/vev-vt/protocol/kittygraphics"
6)
7
8// screenGraphicsState owns the protocol adapter and scene for one VT screen
9// buffer. It is allocated only after the first Kitty graphics APC reaches the
10// screen, so ordinary text writes do not pay for graphics state.
11type screenGraphicsState struct {
12	scene *graphics.Scene
13	kitty *kittygraphics.Session
14}
15
16func newScreenGraphicsState() *screenGraphicsState {
17	scene := graphics.NewScene(graphics.Limits{})
18	return &screenGraphicsState{
19		scene: scene,
20		kitty: kittygraphics.NewSession(scene),
21	}
22}
23
24func (g *screenGraphicsState) snapshot() *graphics.Snapshot {
25	if g == nil || g.scene == nil {
26		return nil
27	}
28	return g.scene.Snapshot()
29}
30
31// clearPlacements applies the ordinary full-screen erase policy without
32// discarding uploaded image mappings. The protocol session owns those
33// mappings, so the operation goes through Kitty's delete-all-visible command
34// rather than mutating the scene directly.
35func (g *screenGraphicsState) clearPlacements() {
36	if g == nil || g.kitty == nil {
37		return
38	}
39	g.kitty.AbortPendingUpload()
40	_, _ = g.kitty.Process(kittygraphics.Command{Controls: kittygraphics.Controls{
41		Action:    kittygraphics.ActionDelete,
42		HasAction: true,
43		Delete:    kittygraphics.DeleteAll,
44		HasDelete: true,
45		Quiet:     kittygraphics.QuietAll,
46		HasQuiet:  true,
47	}})
48}
49
50func (s *Screen) graphicsClearPlacements() {
51	if s == nil {
52		return
53	}
54	if s.graphics != nil {
55		s.graphics.clearPlacements()
56	}
57	s.kittyPendingDisplay = nil
58}
59
60func (s *Screen) abortKittyPendingDisplay() {
61	if s == nil {
62		return
63	}
64	s.kittyPendingDisplay = nil
65	if s.graphics != nil && s.graphics.kitty != nil {
66		s.graphics.kitty.AbortPendingUpload()
67	}
68}
69
70func (s *Screen) abortAllKittyPending() {
71	if s == nil {
72		return
73	}
74	s.abortKittyPendingDisplay()
75	if state := s.alternate; state != nil {
76		state.kittyPendingDisplay = nil
77		if state.graphics != nil && state.graphics.kitty != nil {
78			state.graphics.kitty.AbortPendingUpload()
79		}
80	}
81}
82
83// GraphicsSnapshot returns an immutable snapshot of the active screen
84// buffer's graphics scene, or nil before graphics has been used. The returned
85// reference remains valid after subsequent Screen mutations.
86func (s *Screen) GraphicsSnapshot() *graphics.Snapshot {
87	if s == nil || s.graphics == nil {
88		return nil
89	}
90	return s.graphics.snapshot()
91}