lg_ui.c File Reference

Functions
const char **	lg_camcontrols_keys_str ()
uint32_t	lg_get_user_input (LG_InputState *in, LG_TZW_Array *tzw_array)
LG_TouchZoneWindow *	lg_tzwin_new (const char *str, zboolean no_margin, LG_Color_u text_color, int x_loc, int y_loc, TTF_Font *f)
void	lg_tzwin_show (LG_TouchZoneWindow *tzwin, lg_tzw_type type)
void	lg_tzwin_free (LG_TouchZoneWindow *tzwin)
Rec2Di	lg_tzwin_get_area (LG_TouchZoneWindow *tzwin)
void	lg_draw_rect_corners (Rec2Di r, LG_Color_u c, int len)
void	lg_draw_arrow (Rec2Di r, LG_Color_u c, lg_tzw_type type)
void	lg_rectangle_to_arrow (Rec2Di r, lg_tzw_type arrow_type, Point2Di *p[])
void	lg_draw_triangle (Rec2Di r, LG_Color_u c, lg_tzw_type type)
void	lg_set_special_keys_repeat_delay (uint32_t delay)
LG_TZW_Array *	lg_tzw_array_new ()
zboolean	lg_tzwin_add_to_array (LG_TZW_Array *tzw_array, LG_TouchZoneWindow *tzwin)
LG_TZRec_Array	lg_rec2di_array_from_tzw_array (LG_TZW_Array *tzw_array)
void	lg_tzw_array_free_all_tzwin (LG_TZW_Array *tzw_array)
void	lg_tzw_array_free_all_tzwin_after (LG_TZW_Array *tzw_array, uint32_t next_index)
void	lg_tzw_array_free (LG_TZW_Array *tzw_array)
void	lg_flush_in_clicks (LG_InputState *in)
void	lg_input_state_info (LG_InputState *in)

Detailed Description

 === User Interface things ===

 Get all user input from keyboard, mouse, touchscreen
 Then try to make something coherent out of all that

 === Clickable/tappable areas helper macros for x and y ===
 (in lg_touchscreen.h)

 typedef enum {
    LG_FINGER_DOWN_NO_LOC = 0,
    LG_FINGER_DOWN_LEFT = 1,
    LG_FINGER_DOWN_H_CENTER = 2,
    LG_FINGER_DOWN_RIGHT = 4,
    LG_FINGER_DOWN_BOTTOM = 8,
    LG_FINGER_DOWN_V_CENTER = 16,
    LG_FINGER_DOWN_TOP = 32
 } lg_finger_down_loc;

    (below in this file)

       L     C     R
    -------------------
 T  |     |     |     |
    -------------------
 C  |     |     |     |
    -------------------
 B  |     |     |     |
    -------------------

 TZ_LEFT
 TZ_H_CENTER
 TZ_RIGHT
 TZ_BOTTOM
 TZ_V_CENTER
 TZ_TOP

 === Flight simulator/aircraft specific stuff ===

 yaw + pitch + roll = attitude (Yaw/Pitch/Roll = standard order)
 Other namings:
 yaw = heading, pan / pitch = elevation, tilt / roll = bank

 From: https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/airplane-parts-function/

 Flight controls:
 =========================================================================
 yoke (left/right)       ->      ailerons                        -> roll
 yoke (forward/backward) ->      elevators (on horiz stabilizer) -> pitch
 rudder pedals           ->      rudder (on vert stabilizer)     -> yaw
 thrust lever(s)         ->      thrust
 flaps                   ->      increase lift
 air brakes
 =========================================================================

Function Documentation

lg_camcontrols_keys_str()

const char** lg_camcontrols_keys_str

(

)

Return an array of 9 help strings for cam controls keys

• string[4] -> with <ctrl>
• string[5] -> with <shift>
• string[6] -> with <ctrl><shift>
• string[7] -> with <alt>

Returns

The array of help strings describing what keys do

lg_get_user_input()

uint32_t lg_get_user_input	(	LG_InputState *	in,
		LG_TZW_Array *	tzw_array
	)

Get user input (from keyboard, mouse, touchscreen) in LG_InputState and return in->last_pressed_key (SDLK_*) or LPK_MOUSE_CLICK_ACTIVITY + in->tzw_i in case of mouse left/right click

=== This is the func you should use to get user input inside the game main loop ===

Keyboard controls on Linux:

=========================================================================
|               |     UP      |    DOWN     |    LEFT     |   RIGHT     |
=========================================================================
|               |  move_fwd++ |  move_fwd-- |    yaw--    |    yaw++    |
=========================================================================
| <CTRL>        |   pitch--   |   pitch++   |   roll--    |   roll++    |
=========================================================================
| <SHIFT>       |  v_orbit++  |  v_orbit--  |  h_orbit--  |  h_orbit++  |
=========================================================================
| <CTRL><SHIFT> |  move_up++  |  move_up--  | cam_truck-- | cam_truck++ |
=========================================================================
| <ALT>         |                   slow_motion                         |
=========================================================================

Keys which can be returned by lg_get_user_input() are so far: <enter>, <esc>, <space>, <F1> -> <F12>, <x>, <y>, <z> (see lg_get_special_keys_state())

Delay for <enter>, <esc>, plus <F1> -> <F12> is set to SPECIAL_KEYS_REPEAT_DELAY, can be overridden with lg_set_special_keys_repeat_delay()

Use lg_enable_mouse() / lg_disable_mouse() to read/ignore mouse inputs

On Android, returned value > 0 means requiring action associated with index + 1 of LG_TouchZoneWindow.area array

-> Now set in->tzw_i to index + 1 on both platforms

=== VARO: order of areas matters, ie it goes from left to right ===

Reset last_pressed_key if finger up is detected

NOTE: on Linux, if <up>/<down> with <ctrl><alt> or <ctrl><shift><alt> do nothing, they may have been hijacked by gnome keybindings - check out with dconf: /org/gnome/desktop/wm/keybindings/*

Parameters

in	A pointer to a LG_InputState
tzw_array	A pointer to a LG_TZW_Array

Returns

in->last_pressed_key

lg_tzwin_new()

LG_TouchZoneWindow* lg_tzwin_new	(	const char *	str,
		zboolean	no_margin,
		LG_Color_u	text_color,
		int	x_loc,
		int	y_loc,
		TTF_Font *	f
	)

Create a new LG_TouchZoneWindow

A LG_TouchZoneWindow is a window that is 'clickable' (on Linux) or 'tappable' (on Android) and is rendered in immediate-mode, ie upadated and shown for every frame

=== Set touch_zone area ===

Parameters

str	A string
no_margin
text_color	A LG_Color_u
x	You may also use one of TZ_LEFT, TZ_H_CENTER, TZ_RIGHT
y	You may also use one of TZ_BOTTOM, TZ_V_CENTER, TZ_TOP
f	A TTF_Font

Returns

Addr of a new LG_TouchZoneWindow or NULL on error

lg_tzwin_show()

void lg_tzwin_show	(	LG_TouchZoneWindow *	tzwin,
		lg_tzw_type	type
	)

Show a LG_TouchZoneWindow

Parameters

tzwin	A pointer to a LG_TouchZoneWindow
type	A lg_tzw_type value

lg_tzwin_free()

void lg_tzwin_free

(

LG_TouchZoneWindow *

tzwin

)

Free a LG_TouchZoneWindow

Parameters

tzwin

A pointer to a LG_TouchZoneWindow

lg_tzwin_get_area()

Rec2Di lg_tzwin_get_area

(

LG_TouchZoneWindow *

tzwin

)

Get area (Rec2Di) from a LG_TouchZoneWindow

Parameters

tzwin

A pointer to a LG_TouchZoneWindow

Returns

tzwin->area (a Rec2Di)

lg_draw_rect_corners()

void lg_draw_rect_corners	(	Rec2Di	r,
		LG_Color_u	c,
		int	len
	)

Draw corners of a rect

Parameters

r	A Rec2Di
c	A LG_Color_u
len	Length of corner lines

lg_draw_arrow()

void lg_draw_arrow	(	Rec2Di	r,
		LG_Color_u	c,
		lg_tzw_type	type
	)

Draw an arrow

Parameters

r	A Rec2Di, containing the arrow
c	A LG_Color_u
type	One of TZW_ARROW_UP, TZW_ARROW_DOWN, TZW_ARROW_LEFT, TZW_ARROW_RIGHT, TZW_DOUBLE_ARROW_HORIZ, TZW_DOUBLE_ARROW_VERT

lg_rectangle_to_arrow()

void lg_rectangle_to_arrow	(	Rec2Di	r,
		lg_tzw_type	arrow_type,
		Point2Di *	p[]
	)

Determine the points to draw a lg_tzw_type arrow (with TZW_ARROW_POINTS_NUM points) inside a rectangle

-> up/down/left/right_arrow

Parameters

r	A Rec2Di
arrow_type	A lg_tzw_type value (see lg_draw_arrow() above)
p	An array of Point2Di pointers

lg_draw_triangle()

void lg_draw_triangle	(	Rec2Di	r,
		LG_Color_u	c,
		lg_tzw_type	type
	)

Draw a triangle pointing to left, right, up, down

Parameters

r	A Rec2Di, containg the triangle
c	A LG_Color_u
type	One of TZW_TRIANGLE_LEFT, TZW_TRIANGLE_RIGHT, TZW_TRIANGLE_UP, TZW_TRIANGLE_DOWN

lg_set_special_keys_repeat_delay()

void lg_set_special_keys_repeat_delay

(

uint32_t

delay

)

Set func keys repeat delay

Parameters

delay

Delay in ms

lg_tzw_array_new()

LG_TZW_Array* lg_tzw_array_new

(

)

Create a new LG_TZW_Array and initialize it

(TZW and TZ win are shorts for LG_TouchZoneWindow)

The purpose of this struct is to keep an array of changeable TZ wins to show at each frame and to know which one was 'activated' (clicked or tapped)

#define N_TZW_MAX  256
 
// Array of all TZ wins for one frame
 
typedef struct {
   LG_TouchZoneWindow    *tzw[N_TZW_MAX];
} LG_TZW_Array;
 
typedef struct {
   Rec2Di        *r[N_TZW_MAX];
   Rec2Di        r0[N_TZW_MAX];
} LG_TZRec_Array;

After that, when adding/removing TZ wins, order matters, ie it goes from left to right

When a TZ win area is clicked/tapped, LG_InputState->tzw_i is set to index + 1

// uint32_t lg_get_user_input(LG_InputState *in, Rec2Di **r)       // ie Rec2Di *[]
 
LG_InputState *in;
LG_TZW_Array *tzw_array = lg_tzw_array_new();
LG_TZRec_Array r_array = lg_rec2di_array_from_tzw_array(tzw_array);
 
lg_get_user_input(in, (Rec2Di **)&r_array.r);

Use in->tzw_i to decide which action to take, knowing that:

• in->tzw_i = index + 1 of clicked/tapped TZ win in TZ win array
• in->tzw_i = 0 means no TZ win was clicked/tapped

This API seems a bit complicated at first, but to get a better sense of how it works, make sure to check out the code in scene_editor/main_loop.c, where it is used extensively

Returns

A pointer to the new LG_TZW_Array if OK, NULL on error

lg_tzwin_add_to_array()

zboolean lg_tzwin_add_to_array	(	LG_TZW_Array *	tzw_array,
		LG_TouchZoneWindow *	tzwin
	)

Add a TZ win at first NULL element found

Parameters

tzw_array	Pointer to a LG_TZW_Array
tzwin	Pointer to a LG_TouchZoneWindow

Returns

TRUE if OK, FALSE on error

lg_rec2di_array_from_tzw_array()

LG_TZRec_Array lg_rec2di_array_from_tzw_array

(

LG_TZW_Array *

tzw_array

)

Create and return a LG_TZRec_Array from a LG_TZW_Array

Parameters

tzw_array

Pointer to a LG_TZW_Array

Returns

A new LG_TZRec_Array

lg_tzw_array_free_all_tzwin()

void lg_tzw_array_free_all_tzwin

(

LG_TZW_Array *

tzw_array

)

Free all TZ win from a TZ win array

Parameters

tzw_array

Pointer to a LG_TZW_Array

lg_tzw_array_free_all_tzwin_after()

void lg_tzw_array_free_all_tzwin_after	(	LG_TZW_Array *	tzw_array,
		uint32_t	next_index
	)

Free all TZ win after next_index from a TZ win array

Parameters

tzw_array	Pointer to a LG_TZW_Array
next_index

lg_tzw_array_free()

void lg_tzw_array_free

(

LG_TZW_Array *

tzw_array

)

Free a TZ win array

Parameters

tzw_array

Pointer to a LG_TZW_Array

lg_flush_in_clicks()

void lg_flush_in_clicks

(

LG_InputState *

in

)

Flush mouse clicks and reset associated states in LG_InputState

Parameters

in	Pointer to LG_InputState

lg_input_state_info()

void lg_input_state_info

(

LG_InputState *

in

)

Take a snapshot of user input state

Parameters

in	LG_InputState