zoom_view_t Struct Reference

Live viewport: where it is looking, how magnified, and what it owes the panel. More...

#include <zoom.h>

Collaboration diagram for zoom_view_t:

Data Fields
zoom_source_t	src
	Bound source.
zoom_scratch_t	scratch
	Caller-owned composite buffers.
ra8_ui_rect_t	dst
	Viewport in framebuffer pixels.
int32_t	anchor_x
	Plane column shown at dst.x.
int32_t	anchor_y
	Plane row shown at dst.y.
uint32_t	last_input_ms
	Timestamp of the last viewport change.
uint16_t	settle_ms
	Input silence before the quality repaint.
uint16_t	strip_rows
	Destination rows per composite strip.
uint8_t	scale
	Current integer magnification.
uint8_t	scale_max
	Ladder ceiling for this view.
zoom_policy_t	policy
	Waveform scheduling policy.
zoom_refresh_t	pending_kind
	Waveform the owed flush should use.
bool	pending
	A flush is owed.
bool	settle_armed
	A quality repaint is still due after settling.
bool	active
	The view is open.

Detailed Description

Live viewport: where it is looking, how magnified, and what it owes the panel.

Opaque by convention – read it through the accessors, never write it. The two anchor fields are the state that matters and they are in magnified-plane coordinates (see the file docblock), so anchor_x + c is the plane column shown at destination column c and (anchor_x + c) / scale is the source column.

Invariant

scale lies in [k_zoom_scale_min, scale_max] whenever active.

anchor_x is clamped to [0, width*scale - dst.w] when the image is wider than the viewport, and is the negative centring offset otherwise.

strip_rows >= 1 and strip_rows <= k_zoom_strip_rows_max.

settle_armed is false under k_zoom_policy_quality.

State transitions

State transition table

State	Event	Next state	Action
closed	view_open	quality pending	anchor from focus, clamp
any pending	view_present	shown	hand the rect + waveform to the caller
shown	view_pan / view_set_scale	fast (responsive) or quality pending	re-clamp anchor, arm settle
shown	view_tick past settle_ms	quality pending	disarm settle
any	view_close	closed	nothing owed

Example:

static zoom_view_t s_view;
(void)zoom_view_open(&s_view, &cfg);

See also

zoom_view_open

Since

0.1.0

Definition at line 472 of file zoom.h.

Field Documentation

active

bool zoom_view_t::active

The view is open.

Definition at line 487 of file zoom.h.

Referenced by internal_render_ready(), internal_view_adopt(), zoom_view_active(), zoom_view_close(), zoom_view_invalidate(), zoom_view_open(), zoom_view_pan(), zoom_view_pan_dir(), zoom_view_present(), zoom_view_rebind(), zoom_view_set_scale(), zoom_view_tick(), and zoom_view_window().

anchor_x

int32_t zoom_view_t::anchor_x

Plane column shown at dst.x.

Definition at line 476 of file zoom.h.

Referenced by internal_emit_strip(), internal_expand_row(), internal_reclamp(), internal_view_adopt(), zoom_view_pan(), zoom_view_render(), zoom_view_set_scale(), and zoom_view_window().

anchor_y

int32_t zoom_view_t::anchor_y

Plane row shown at dst.y.

Definition at line 477 of file zoom.h.

Referenced by internal_emit_strip(), internal_fill_strip(), internal_reclamp(), internal_view_adopt(), zoom_view_pan(), zoom_view_set_scale(), and zoom_view_window().

dst

ra8_ui_rect_t zoom_view_t::dst

Viewport in framebuffer pixels.

Definition at line 475 of file zoom.h.

Referenced by internal_emit_strip(), internal_fill_strip(), internal_reclamp(), internal_view_adopt(), zoom_view_pan_dir(), zoom_view_present(), zoom_view_render(), zoom_view_set_scale(), and zoom_view_window().

last_input_ms

uint32_t zoom_view_t::last_input_ms

Timestamp of the last viewport change.

Definition at line 478 of file zoom.h.

Referenced by internal_touch(), internal_view_adopt(), and zoom_view_tick().

pending

bool zoom_view_t::pending

A flush is owed.

Definition at line 485 of file zoom.h.

Referenced by internal_touch(), internal_view_adopt(), zoom_view_close(), zoom_view_present(), and zoom_view_tick().

pending_kind

zoom_refresh_t zoom_view_t::pending_kind

Waveform the owed flush should use.

Definition at line 484 of file zoom.h.

Referenced by internal_touch(), internal_view_adopt(), zoom_view_present(), and zoom_view_tick().

policy

zoom_policy_t zoom_view_t::policy

Waveform scheduling policy.

Definition at line 483 of file zoom.h.

Referenced by internal_touch(), and internal_view_adopt().

scale

uint8_t zoom_view_t::scale

Current integer magnification.

Definition at line 481 of file zoom.h.

Referenced by ez_draw_status(), ez_scene_tap(), internal_expand_row(), internal_fill_row(), internal_reclamp(), internal_view_adopt(), zoom_view_render(), zoom_view_set_scale(), and zoom_view_window().

scale_max

uint8_t zoom_view_t::scale_max

Ladder ceiling for this view.

Definition at line 482 of file zoom.h.

Referenced by internal_view_adopt(), and zoom_view_set_scale().

scratch

zoom_scratch_t zoom_view_t::scratch

Caller-owned composite buffers.

Definition at line 474 of file zoom.h.

Referenced by internal_emit_strip(), internal_expand_row(), internal_fill_row(), internal_fill_strip(), and internal_view_adopt().

settle_armed

bool zoom_view_t::settle_armed

A quality repaint is still due after settling.

Definition at line 486 of file zoom.h.

Referenced by internal_touch(), internal_view_adopt(), zoom_view_close(), and zoom_view_tick().

settle_ms

uint16_t zoom_view_t::settle_ms

Input silence before the quality repaint.

Definition at line 479 of file zoom.h.

Referenced by internal_view_adopt(), and zoom_view_tick().

src

zoom_source_t zoom_view_t::src

Bound source.

Definition at line 473 of file zoom.h.

Referenced by internal_fill_row(), internal_reclamp(), internal_render_ready(), internal_view_adopt(), zoom_view_rebind(), zoom_view_render(), and zoom_view_window().

strip_rows

uint16_t zoom_view_t::strip_rows

Destination rows per composite strip.

Definition at line 480 of file zoom.h.

Referenced by internal_render_ready(), internal_view_adopt(), and zoom_view_render().

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The documentation for this struct was generated from the following file:

• apps/shared_libs/zoom/inc/zoom.h