lg_misc.c File Reference

Functions
void	lg_enable_transparency ()
void	lg_disable_transparency ()
int	lg_check_gl_errors (long long log_time, const char *file, int line, const char *func)
int	lg_check_gl_context ()
lg_endianness	lg_get_arch_endianness ()
float	lg_tv_diff (struct timeval *t_diff, struct timeval *t2, struct timeval *t1)
int	delta_i (int i)
float	delta_f (float f)
zboolean	has_changed_i (int i)
zboolean	has_changed_f (float f)
double	clamp (double v, double min, double max)
void *	lg_align_up_to_next_4_bytes_boundary (void *addr)
void *	lg_align_up_to_next_8_bytes_boundary (void *addr)
void	lg_swap_values (void *x, void *y, WidthInBytes width)
void	debug_start_max_int_in_loop ()
void	debug_max_int_in_loop (unsigned long i, const char *file, int line)
void	debug_end_max_int_in_loop ()
void	debug_start_max_float_in_loop ()
void	debug_max_float_in_loop (float f, const char *file, int line)
void	debug_end_max_float_in_loop ()
int	lg_check_datatype_sizes ()
void	lg_show_struct_sizes (zboolean everything)
int	lg_show_pixel_format_info_from_sdl_display_mode (SDL_DisplayMode *display_mode)
void	lg_show_utf8_drawings (zboolean extra_n)

Detailed Description

 A loose collection of funcs that don't belong to a specific module (so far ...)

Function Documentation

lg_enable_transparency()

void lg_enable_transparency

(

)

Enabling transparency before calling glDraw* funcs

lg_disable_transparency()

void lg_disable_transparency

(

)

Disabling transparency (default)

lg_check_gl_errors()

int lg_check_gl_errors	(	long long	log_time,
		const char *	file,
		int	line,
		const char *	func
	)

Check GL errors

Parameters

log_time	lg_log_time()
file	__ FILE __ (without spaces)
line	__ LINE __ (without spaces)
func	__ func __ (without spaces)

Returns

LG_OK if OK

lg_check_gl_context()

int lg_check_gl_context

(

)

Check OpenGL context, ie if the current context is not NULL and whether it has changed since app startup

Returns

LG_OK if OK, LG_ERROR otherwise

lg_get_arch_endianness()

lg_endianness lg_get_arch_endianness

(

)

Get architecture endianness

From: https://developer.ibm.com/articles/au-endianc/

Returns

LG_LITTLE_ENDIAN or LG_BIG_ENDIAN

lg_tv_diff()

float lg_tv_diff	(	struct timeval *	t_diff,
		struct timeval *	t2,
		struct timeval *	t1
	)

Compute t2 - t1 (in s and µs), store the result in t_diff (in s and µs), and return diff in ms (as a float)

Example use:

struct timeval t1, t2, t_diff;
 
gettimeofday(&t1, NULL);
// Do sth
gettimeofday(&t2, NULL);
 
VERBOSE_INFO_OUT("Doing sth: done in %d ms\n", (int)lg_tv_diff(&t_diff, &t2, &t1));

Parameters

t_diff	A pointer to a struct timeval
t2	A pointer to a struct timeval
t1	A pointer to a struct timeval

Returns

t_diff in (float) ms

delta_i()

int delta_i

(

int

i

)

Return delta of an int value since last call

Parameters

i	An int value

Returns

The difference as an int

delta_f()

float delta_f

(

float

f

)

Return delta of a float value since last call

Parameters

f	A float value

Returns

The difference as a float

has_changed_i()

zboolean has_changed_i

(

int

i

)

Check if an int value has changed since last call

Parameters

i	An int value

Returns

TRUE if value has changed, FALSE otherwise

has_changed_f()

zboolean has_changed_f

(

float

f

)

Check if a float value has changed since last call, using LG_FLOAT_EPSILON for comparison

Parameters

f	A float value

Returns

TRUE if value has changed, FALSE otherwise

clamp()

double clamp	(	double	v,
		double	min,
		double	max
	)

Clamp implementation

Parameters

v	Value to clamp
min	Min value
max	Max value

Returns

Clamped value

lg_align_up_to_next_4_bytes_boundary()

void * lg_align_up_to_next_4_bytes_boundary

(

void *

addr

)

Align memory addr up to next 4 bytes boundary, unless already aligned

Parameters

addr	Memory address

Returns

The new aligned addr

lg_align_up_to_next_8_bytes_boundary()

void * lg_align_up_to_next_8_bytes_boundary

(

void *

addr

)

Align memory addr up to next 8 bytes boundary, unless already aligned

Parameters

addr	Memory address

Returns

The new aligned addr

lg_swap_values()

void lg_swap_values	(	void *	x,
		void *	y,
		WidthInBytes	width
	)

Portable value swapping

No input checking is done

Helper typdef for width in bytes

typedef enum {
   WBY_8_BIT =     1,
   WBY_16_BIT =    2,
   WBY_32_BIT =    4,
   WBY_64_BIT =    8
} WidthInBytes;

Parameters

x	Pointer to value #1
y	Pointer to value #2
width	Width in bytes of value type

debug_start_max_int_in_loop()

void debug_start_max_int_in_loop

(

)

For debugging purposes - 'Reset' max_int_in_loop

debug_max_int_in_loop()

void debug_max_int_in_loop	(	unsigned long	i,
		const char *	file,
		int	line
	)

For debugging purposes - Print out max value found so far while running loop

Example use:

 i = 0;
 debug_start_max_int_in_loop();
 for (y = 0; y < h; y++) {
    for (x = 0; x < w; x++) {
            debug_max_int_in_loop((unsigned long)i, __FILE__, __LINE__);
            // ...
            terrain->vbo_data[i].x = (float)x / (float)w;
            terrain->vbo_data[i].y = heightmap[x + y * w] * vert_scaling_k;
            terrain->vbo_data[i].z = (float)y / (float)h;
            // ...
            i++;
    }
 }
 debug_end_max_int_in_loop();

Parameters

i	Integer to test
file	Should be "__FILE__"
line	Should be "__LINE__"

debug_end_max_int_in_loop()

void debug_end_max_int_in_loop

(

)

For debugging purposes - Just print out closing '\n'

debug_start_max_float_in_loop()

void debug_start_max_float_in_loop

(

)

For debugging purposes - 'Reset' max_float_in_loop

debug_max_float_in_loop()

void debug_max_float_in_loop	(	float	f,
		const char *	file,
		int	line
	)

For debugging purposes - Print out max value found so far while running loop

Example use: same as above with float instead of int

Parameters

f	float to test
file	Should be "__FILE__"
line	Should be "__LINE__"

debug_end_max_float_in_loop()

void debug_end_max_float_in_loop

(

)

For debugging purposes - Just print out closing '\n'

lg_check_datatype_sizes()

int lg_check_datatype_sizes

(

)

Check C and OpenGL types at runtime - should be called early at init time

Also see: https://www.khronos.org/opengl/wiki/OpenGL_Type

Returns

LG_OK if OK

lg_show_struct_sizes()

void lg_show_struct_sizes

(

zboolean

everything

)

Mainly for internal testing, but quite informative about memory consumption

Make sure to add new structs

Parameters

everything

Every structs if TRUE , only big or new/interesting ones otherwise

lg_show_pixel_format_info_from_sdl_display_mode()

int lg_show_pixel_format_info_from_sdl_display_mode

(

SDL_DisplayMode *

display_mode

)

Show pixel format info bla bla

See: https://wiki.libsdl.org/SDL_PixelFormat

Parameters

display_mode

Pointer to a SDL_DisplayMode struct

Returns

LG_OK if OK

lg_show_utf8_drawings()

void lg_show_utf8_drawings

(

zboolean

extra_n

)

Helper func to draw some UTF-8 stuff like arrows, lines, and corners, along with their hex codes and tokens

Is that any useful actually ?

Pretty handy when trying to draw UTF-8 boxes

Parameters

extra_n

Add an extra "\n" at end of lines (will look less "compact")