lg_gr_func.c File Reference

Functions
void	lg_draw_line (int32_t x1, int32_t y1, int32_t x2, int32_t y2, LG_Color_u c)
void	lg_draw_rect (Rec2Di r, LG_Color_u c)
void	lg_fill_rect (Rec2Di r, LG_Color_u c)
void	lg_clear_rect (Rec2Di r, LG_Color_u c)
zboolean	lg_clip_rect (Rec2Di clip, Rec2Di rect, Rec2Di *clipped_rect)
zboolean	lg_recs_overlap (Rec2Df *r1, Rec2Df *r2)
void	lg_copy_rect (Rec2Di src, Rec2Di *dest)
void	lg_rec_i_copy (Rec2Di *dest, Rec2Di src)
void	lg_rec_f_copy (Rec2Df *dest, Rec2Df src)
Rec2Di	lg_rec_i (int x, int y, int w, int h)
Rec2Df	lg_rec_f (float x, float y, float w, float h)
Rec2Df	lg_rec_f_from_rec_i (Rec2Di r)
Rec2Di	lg_rec_i_from_rec_f (Rec2Df r)
Point2Di	lg_point2d_i (int32_t x, int32_t y)
Point2Df	lg_point2d_f (float x, float y)
Point2Di	lg_rec_i_center (Rec2Di r)
Point2Df	lg_rec_f_center (Rec2Df r)
void	gl_coords_from_screen_coords (float *x2, float *y2, int x1, int y1, int viewport_w, int viewport_h)
void	logical_coords_from_viewport_coords (int *x2, int *y2, int x1, int y1)
void	logical_coords_from_viewport_coords_btaskbar_adjustment (int bth_adj)
void	logical_coords_from_touchscreen_coords (int *x2, int *y2, float x1, float y1)
void	lg_set_touchscreen_coords_margins (float left, float top)
uint32_t	lg_point2di_is_inside_rec2di_from_array (Point2Di p, Rec2Di **r, uint32_t n_rect_max)
uint32_t	lg_point2f_is_inside_rec2df_from_array (Point2Df p, Rec2Df **r, uint32_t n_rect_max)
int32_t	sdl_to_gl_int_x (int32_t x)
int32_t	sdl_to_gl_int_y (int32_t y)
float	sdl_to_gl_float_x (int32_t x)
float	sdl_to_gl_float_y (int32_t y)
LG_Color_u	lg_color_u_from_sdl_color (SDL_Color c)
SDL_Color	lg_sdl_color_from_lg_color_u (LG_Color_u c)
SDL_Color *	lg_set_sdl_color_from_str (SDL_Color *c, const char *str)
SDL_Color	lg_get_sdl_color_from_str (const char *str)
LG_Color_u *	lg_set_lg_color_u_from_str (LG_Color_u *c, const char *str)
LG_Color_u	lg_get_lg_color_u_from_str (const char *str)
int	lg_get_n_color_str ()
const char *	lg_get_color_str_from_color_index (int i)
void	v_flip_sdl_surf (SDL_Surface *surf)

Detailed Description

  === A few 2D structs and graphical funcsPlus colors funcs ===

    Plus colors funcs

 Quite messy, also a lot of convenience conversion funcs

Function Documentation

lg_draw_line()

void lg_draw_line	(	int32_t	x1,
		int32_t	y1,
		int32_t	x2,
		int32_t	y2,
		LG_Color_u	c
	)

Draw a line from (x1, y1) to (x2, y2)

Expect SDL coords sys (logical coords, ie inside [0 -> env->top_win_logical_w] x [0 -> env->top_win_logical_h])

Parameters

x1	Origin x coord
y1	Origin y coord
x2	Dest x coord
y2	Dest y coord
c	A LG_Color_u

lg_draw_rect()

void lg_draw_rect	(	Rec2Di	r,
		LG_Color_u	c
	)

Draw a rectangle

Expect SDL coords sys (logical coords, ie inside [0 -> env->top_win_logical_w] x [0 -> env->top_win_logical_h])

Parameters

r	A Rec2Di
c	A LG_Color_u

lg_fill_rect()

void lg_fill_rect	(	Rec2Di	r,
		LG_Color_u	c
	)

Fill a rectangle with color - now just call lg_render_rect_2d()

Expect SDL coords sys (logical coords, ie inside [0 -> env->top_win_logical_w] x [0 -> env->top_win_logical_h])

lg_fill_rect() is about three times faster than lg_clear_rect()

 In test/test.c: test_lg_draw_fill_rect()):
 - Time to draw with lg_clear_rect() = 6.582 ms
 - Time to draw with lg_fill_rect() = 1.925 ms

Parameters

r	A Rec2Di
c	A LG_Color_u

lg_clear_rect()

void lg_clear_rect	(	Rec2Di	r,
		LG_Color_u	c
	)

Clear a rectangle with color

Expect SDL coords sys (logical coords, ie inside [0 -> env->top_win_logical_w] x [0 -> env->top_win_logical_h])

lg_clear_rect() is about three times slower than lg_fill_rect() (see above)

Parameters

r	A Rec2Di
c	A LG_Color_u

lg_clip_rect()

zboolean lg_clip_rect	(	Rec2Di	clip,
		Rec2Di	rect,
		Rec2Di *	clipped_rect
	)

Return FALSE if rect is fully outside clip. Otherwise, set clipped_rect (rect is unchanged) and return TRUE.

lg_recs_overlap()

zboolean lg_recs_overlap	(	Rec2Df *	r1,
		Rec2Df *	r2
	)

Test if 2 rects (Rec2Df) overlap

Using Rec2Df with OpenGL coords sys orientation

typedef struct {
        float   x;
        float   y;
        float   w;
        float   h;
} Rec2Df;
 
      ^
      |
x,y+h |--------
      |       |
      |       |
      ------------->
     x,y          x+w,y

Parameters

r1	Pointer to a Rec2Df
r2	Pointer to a Rec2Df

Returns

TRUE if the rects overlap, FALSE otherwise

lg_copy_rect()

void lg_copy_rect	(	Rec2Di	src,
		Rec2Di *	dest
	)

TODO: should be lg_copy_rect(dest, src) for consistency sake

DEPRECATED anyways

Parameters

src
dest

lg_rec_i_copy()

void lg_rec_i_copy	(	Rec2Di *	dest,
		Rec2Di	src
	)

Copy src Rec2Di to dest Rec2Di

Parameters

dest	A pointer to a Rec2Di
src	A Rec2Di

lg_rec_f_copy()

void lg_rec_f_copy	(	Rec2Df *	dest,
		Rec2Df	src
	)

Copy src Rec2Df to dest Rec2Df

Parameters

dest	A pointer to a Rec2Df
src	A Rec2Df

lg_rec_i()

Rec2Di lg_rec_i	(	int	x,
		int	y,
		int	w,
		int	h
	)

Set a Rec2Di

Parameters

x
y
w
h

Returns

A Rec2Di

lg_rec_f()

Rec2Df lg_rec_f	(	float	x,
		float	y,
		float	w,
		float	h
	)

Set a Rec2Df

Parameters

x
y
w
h

Returns

A Rec2Df

lg_rec_f_from_rec_i()

Rec2Df lg_rec_f_from_rec_i

(

Rec2Di

r

)

Get Rec2Df from Rec2Di

Parameters

r

A Rec2Di

Returns

A Rec2Df

lg_rec_i_from_rec_f()

Rec2Di lg_rec_i_from_rec_f

(

Rec2Df

r

)

Get Rec2Di from Rec2Df

This func uses lroundf()

Parameters

r

A Rec2Df

Returns

A Rec2Di

lg_point2d_i()

Point2Di lg_point2d_i	(	int32_t	x,
		int32_t	y
	)

Create a Point2Di

Parameters

x
y

Returns

A new Point2Di

lg_point2d_f()

Point2Df lg_point2d_f	(	float	x,
		float	y
	)

Create a Point2Df

Parameters

x
y

Returns

A new Point2Df

lg_rec_i_center()

Point2Di lg_rec_i_center

(

Rec2Di

r

)

Compute center of rectangle

This func uses lroundf()

Parameters

r

A Rec2Di

Returns

The center as a Rec2Di

lg_rec_f_center()

Point2Df lg_rec_f_center

(

Rec2Df

r

)

Compute center of rectangle

Parameters

r

A Rec2Df

Returns

The center as a Point2Df

gl_coords_from_screen_coords()

void gl_coords_from_screen_coords	(	float *	x2,
		float *	y2,
		int	x1,
		int	y1,
		int	viewport_w,
		int	viewport_h
	)

Get GL coords (more exactly NDC) in range [-1, 1] x [-1, 1] with origin at center from some screen coords in range [0, some screen width] x [0, some screen height] with origin at top left corner

On Linux, useful to get mouse pointer NDC coords for ray picking or whatever

Parameters

x2	(GL coord)
y2	(GL coord)
x1	(Screen coord)
y1	(Screen coord)
viewport_w	Usually env->viewport_rect.w
viewport_h	Usually env->viewport_rect.h

logical_coords_from_viewport_coords()

void logical_coords_from_viewport_coords	(	int *	x2,
		int *	y2,
		int	x1,
		int	y1
	)

Get logical coords in range [0, env->top_win_logical_w] x [0, env->top_win_logical_h] from viewport coords in range [0, env->viewport_rect.w] x [0, env->viewport_rect.h] from current LG_Env

On Linux, useful to get 'logical' mouse pointer coords (you may need to use logical_coords_from_viewport_coords_btaskbar_adjustment() to get accurate results)

Parameters

x2	(Logical coord)
y2	(Logical coord)
x1	(Viewport coord)
y1	(Viewport coord)

logical_coords_from_viewport_coords_btaskbar_adjustment()

void logical_coords_from_viewport_coords_btaskbar_adjustment

(

int

bth_adj

)

Set (static int) bottom_taskbar_height_adjustment to correct logical_coords_from_viewport_coords() y2 inaccuracy

Linux only - should find how to get bottom taskbar height

Parameters

bth_adj

Bottom taskbar height adjustment

logical_coords_from_touchscreen_coords()

void logical_coords_from_touchscreen_coords	(	int *	x2,
		int *	y2,
		float	x1,
		float	y1
	)

Get logical coords in range [0, env->top_win_logical_w] x [0, env->top_win_logical_h] from touchscreen coords in range [0.0, 1.0] x [0.0, 1.0]

Useful to get 'logical' touch coords on Android

Parameters

x2	(Logical coord)
y2	(Logical coord)
x1	(Viewport coord)
y1	(Viewport coord)

lg_set_touchscreen_coords_margins()

void lg_set_touchscreen_coords_margins	(	float	left,
		float	top
	)

Used by logical_coords_from_touchscreen_coords() to adjust stuff

Use this func only if you know what you're doing

Parameters

left	Left margin value
top	Top margin value

lg_point2di_is_inside_rec2di_from_array()

uint32_t lg_point2di_is_inside_rec2di_from_array	(	Point2Di	p,
		Rec2Di **	r,
		uint32_t	n_rect_max
	)

Test against all rect (Rec2Di) from an array if a point (Point2Di) is inside one of them

NOTE: comparing with >= and <=

Parameters

p	A Point2Di
r	Pointer to an array of Rec2Di
n_rect_max	Max num of rect in the array

Returns

The index + 1 of the rect in the array or 0 if it is in none

lg_point2f_is_inside_rec2df_from_array()

uint32_t lg_point2f_is_inside_rec2df_from_array	(	Point2Df	p,
		Rec2Df **	r,
		uint32_t	n_rect_max
	)

Test against all rect (Rect2Df) from an array if a point (Point2Df) is inside one of them

NOTE: comparing with >= and <=

Parameters

p	A Point2Df
r	Pointer to a NULL-terminated array of Rec2Df
n_rect_max	Max num of rect in the array

Returns

The index + 1 of the rect in the array or 0 if it is in none

sdl_to_gl_int_x()

int32_t sdl_to_gl_int_x

(

int32_t

x

)

Convert from SDL coords to OpenGL coords

Parameters

x

Returns

New value as an int

sdl_to_gl_int_y()

int32_t sdl_to_gl_int_y

(

int32_t

y

)

Convert from SDL coords to OpenGL coords

Parameters

y

Returns

New value as an int

sdl_to_gl_float_x()

float sdl_to_gl_float_x

(

int32_t

x

)

Convert from SDL coords to OpenGL coords

About the 0.375 value, see: https://www.opengl.org/archives/resources/faq/technical/transformations.htm

Parameters

x

Returns

New value as a float

sdl_to_gl_float_y()

float sdl_to_gl_float_y

(

int32_t

y

)

Convert from SDL coords to OpenGL coords

About the 0.375 value, see: https://www.opengl.org/archives/resources/faq/technical/transformations.htm

Parameters

y

Returns

New value as a float

lg_color_u_from_sdl_color()

LG_Color_u lg_color_u_from_sdl_color

(

SDL_Color

c

)

Get LG_Color_u from SDL_Color

Parameters

c	A SDL_Color

Returns

A LG_Color_u

lg_sdl_color_from_lg_color_u()

SDL_Color lg_sdl_color_from_lg_color_u

(

LG_Color_u

c

)

Get SDL_Color from LG_Color_u

Parameters

c	LG_Color_u

Returns

A SDL_Color

lg_set_sdl_color_from_str()

SDL_Color* lg_set_sdl_color_from_str	(	SDL_Color *	c,
		const char *	str
	)

Bla bla (self-explanatory)

lg_get_sdl_color_from_str()

SDL_Color lg_get_sdl_color_from_str

(

const char *

str

)

Bla bla (self-explanatory)

lg_set_lg_color_u_from_str()

LG_Color_u* lg_set_lg_color_u_from_str	(	LG_Color_u *	c,
		const char *	str
	)

Bla bla (self-explanatory)

lg_get_lg_color_u_from_str()

LG_Color_u lg_get_lg_color_u_from_str

(

const char *

str

)

Bla bla (self-explanatory)

lg_get_n_color_str()

int lg_get_n_color_str

(

)

Bla bla (self-explanatory)

lg_get_color_str_from_color_index()

const char* lg_get_color_str_from_color_index

(

int

i

)

Bla bla (self-explanatory)

v_flip_sdl_surf()

void v_flip_sdl_surf

(

SDL_Surface *

surf

)

Flip (vertical one) SDL surf

TODO: fix the compilation warning

(From gcc doc) === gcc option -Wpointer-arith ===

Warn about anything that depends on the “size of” a function type or of void. GNU C assigns these types a size of 1, for convenience in calculations with void * pointers and pointers to functions.

(WTF ?)