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)
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 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 coord 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 coord 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 coord 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 coord 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 coord 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 roundf()

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 roundf()

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

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 ?)