gfx_draw.c File Reference

A SDL2 based library to implement work queue based drawing of graphical elements. Allows for drawing using SDL2 from multiple threads. More...

#include <linux/limits.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <SDL2/SDL.h>
#include <SDL2/SDL2_gfxPrimitives.h>
#include <SDL2/SDL_image.h>
#include <pthread.h>
#include "gfx_draw.h"
#include "gfx_font.h"
#include "gfx_utils.h"
#include "gfx_print.h"

Classes
struct	loaded_image
struct	loaded_image_crop
struct	spritesheet_sequence
struct	spritesheet
struct	animated_image
struct	animated_sequence_instance
struct	clear_data
struct	arc_data
struct	ellipse_data
struct	rect_data
struct	circle_data
struct	line_data
struct	poly_data
struct	triangle_data
struct	image_data
struct	loaded_image_data
struct	scaled_image_data
struct	text_data
struct	arrow_data
union	data_u
struct	draw_job
struct	global_offsets

Macros
#define	ONE_BYTE   8
#define	TWO_BYTES   16
#define	THREE_BYTES   24
#define	MAX_8_BIT   255
#define	ALPHA_SOLID   MAX_8_BIT
#define	FIRST_BYTE   0x000000ff
#define	SECOND_BYTE   0x0000ff00
#define	THIRD_BYTE   0x00ff0000
#define	FOURTH_BYTE   0xff000000
#define	RED_PORTION(COLOUR)   (COLOUR & 0xFF0000) >> TWO_BYTES
#define	GREEN_PORTION(COLOUR)   (COLOUR & 0x00FF00) >> ONE_BYTE
#define	BLUE_PORTION(COLOUR)   (COLOUR & 0x0000FF)
#define	ZERO_ALPHA   0
#define	PRINT_SDL_ERROR(msg, ...)
#define	INIT_JOB(JOB, TYPE)
#define	NS_IN_SECOND   1000000000.0
#define	MS_IN_SECOND   1000.0
#define	NS_IN_MS   1000000.0

Typedefs
typedef struct loaded_image	loaded_image_t
typedef struct loaded_image_crop	loaded_image_crop_t
typedef struct spritesheet_sequence	spritesheet_sequence_t
typedef struct spritesheet	spritesheet_t
typedef struct animated_image	animated_image_t
typedef struct animated_sequence_instance	animated_sequence_instance_t
typedef struct clear_data	clear_data_t
typedef struct arc_data	arc_data_t
typedef struct ellipse_data	ellipse_data_t
typedef struct rect_data	rect_data_t
typedef struct circle_data	circle_data_t
typedef struct line_data	line_data_t
typedef struct poly_data	poly_data_t
typedef struct triangle_data	triangle_data_t
typedef struct image_data	image_data_t
typedef struct loaded_image_data	loaded_image_data_t
typedef struct scaled_image_data	scaled_image_data_t
typedef struct text_data	text_data_t
typedef struct arrow_data	arrow_data_t
typedef struct draw_job	draw_job_t

Enumerations
enum	draw_job_type_t {   DRAW_NONE = 0 , DRAW_CLEAR , DRAW_ARC , DRAW_ELLIPSE ,   DRAW_TEXT , DRAW_RECT , DRAW_FILLED_RECT , DRAW_CIRCLE ,   DRAW_LINE , DRAW_POLY , DRAW_TRIANGLE , DRAW_IMAGE ,   DRAW_LOADED_IMAGE , DRAW_LOADED_IMAGE_CROP , DRAW_SCALED_IMAGE , DRAW_ARROW }

Functions
void	_setErrorMessage (char *msg)
gfx_animation_handle_t	gfxDrawAnimationCreate (gfx_spritesheet_handle_t spritesheet)
	Creates an animation object with an attached spritesheet that must be loaded prior as an image. More...
int	gfxDrawAnimationAddSequence (gfx_animation_handle_t animation, char *name, unsigned start_row, unsigned start_col, enum sprite_sequence_direction sprite_step_direction, unsigned frames)
	Adds an animation sequence to a previously created animation. More...
gfx_sequence_handle_t	gfxDrawAnimationSequenceInstantiate (gfx_animation_handle_t animation, char *sequence_name, unsigned frame_period_ms)
	Creates an instance of an animation from a loaded animation object and a sequence name of a sequence previously added to the animation object. More...
int	xDrawLoadedImageCropped (loaded_image_t *img, SDL_Renderer *ren, signed short x, signed short y, signed short c_x, signed short c_y, signed short c_w, signed short c_h)
int	xDrawLoadedImage (loaded_image_t *img, SDL_Renderer *ren, signed short x, signed short y)
int	gfxDrawUpdateScreen (void)
	Executes the queued draw jobs. More...
char *	gfxGetErrorMessage (void)
	Returns a string error message from the gfx_draw back end. More...
int	gfxDrawInit (char *path)
	Initializes the gfx_draw backend. More...
int	gfxDrawBindThread (void)
	Transfers the drawing ability to the calling thread/taskd. More...
void	gfxDrawExit (void)
	Exits the GFX Draw backend. More...
int	gfxDrawText (char *str, signed short x, signed short y, unsigned int colour)
	Prints a string to the screen. More...
int	gfxGetTextSize (char *str, int *width, int *height)
	Finds the width and height of a strings bounding box. More...
int	gfxDrawCenteredText (char *str, signed short x, signed short y, unsigned int colour)
	Prints a string to the screen. More...
int	gfxDrawEllipse (signed short x, signed short y, signed short rx, signed short ry, unsigned int colour)
	Draws an ellipse on the screen. More...
int	gfxDrawArc (signed short x, signed short y, signed short radius, signed short start, signed short end, unsigned int colour)
	Draws an arc on the screen. More...
int	gfxDrawFilledBox (signed short x, signed short y, signed short w, signed short h, unsigned int colour)
	Draws an unfilled box on the screen. More...
int	gfxDrawBox (signed short x, signed short y, signed short w, signed short h, unsigned int colour)
	Draws a filled box on the screen. More...
void	gfxDrawDuplicateBuffer (void)
int	gfxDrawClear (unsigned int colour)
	Sets the screen to a solid colour. More...
int	gfxDrawCircle (signed short x, signed short y, signed short radius, unsigned int colour)
	Draws a filled circle on the screen. More...
int	gfxDrawLine (signed short x1, signed short y1, signed short x2, signed short y2, unsigned char thickness, unsigned int colour)
	Draws a line on the screen. More...
int	gfxDrawPoly (coord_t *points, int n, unsigned int colour)
	Draws a polygon on the screen. More...
int	gfxDrawTriangle (coord_t *points, unsigned int colour)
	Draws a triangle on the screen. More...
gfx_image_handle_t	gfxDrawLoadScaledImage (char *filename, float scale)
	Loads an image from disk and scales the image, loaded image file can be closed using gfxDrawFreeLoadedImage(). Note that scaled images have large overheads compared to manually scaled images (changing image file's dimensions) More...
gfx_image_handle_t	gfxDrawLoadImage (char *filename)
	Loads an image file from disk, loaded image file can be closed using gfxDrawFreeLoadedImage() More...
int	gfxDrawFreeLoadedImage (gfx_image_handle_t *img)
	Closes a loaded image and frees all memory used by the image structure. More...
int	gfxDrawLoadedImage (gfx_image_handle_t img, signed short x, signed short y)
	Draws a loaded image to the screen. More...
int	gfxDrawSetLoadedImageScale (gfx_image_handle_t img, float scale)
	Scales a loaded image, the scale is a value where, for example, 1.0 represents the original image's size. The scaling factor scales the image relative to the image file's dimensions on disk. More...
float	gfxDrawGetLoadedImageScale (gfx_image_handle_t img)
	Retrieves the current scaling factor of an image. More...
int	gfxDrawGetLoadedImageWidth (gfx_image_handle_t img)
	Retrieves the image's width when drawn to screen, ie. after scaling. More...
int	gfxDrawGetLoadedImageHeight (gfx_image_handle_t img)
	Retrieves the image's height when drawn to screen, ie. after scaling. More...
int	gfxDrawGetLoadedImageSize (gfx_image_handle_t img, int *w, int *h)
	Retrieves bother the image's width and height when drawn to screen, ie. after scaling. More...
int __attribute_deprecated__	gfxDrawImage (char *filename, signed short x, signed short y)
	Draws an image on the screen. More...
spritesheet_t *	gfxDrawInitSpritesheet (gfx_image_handle_t img)
void	gfxDrawSpritesheetSetBoundingBox (spritesheet_t *spritesheet, unsigned bounding_x, unsigned bounding_y, unsigned bounding_w, unsigned bounding_h)
void	gfxDrawSpritesheetSetPadding (spritesheet_t *spritesheet, unsigned padding_x, unsigned padding_y)
void	gfxDrawSpritesheetSetDivisions (spritesheet_t *spritesheet, unsigned cols, unsigned rows)
	Sets the number of cols and rows and in turn the sprite width and height. Should be called AFTER setting the padding and bounding box. More...
gfx_spritesheet_handle_t	gfxDrawLoadSpritesheetFromEntireImageUnpadded (gfx_image_handle_t img, unsigned sprite_cols, unsigned sprite_rows)
	Creates a spritesheet object from a loaded image where each sprite is not padded and the sprite sheet is divided into an number of equal sized rows and columns. More...
gfx_spritesheet_handle_t	gfxDrawLoadSpritesheetFromEntireImagePadded (gfx_image_handle_t img, unsigned sprite_cols, unsigned sprite_rows, unsigned sprite_padding_x, unsigned sprite_padding_y)
	Creates a spritesheet object from a loaded image where sprites are padded. More...
gfx_spritesheet_handle_t	gfxDrawLoadSpritesheetFromEntireImagePaddedSpacing (gfx_image_handle_t img, unsigned sprite_cols, unsigned sprite_rows, unsigned sprite_spacing_x, unsigned sprite_spacing_y)
	Creates a spritesheet object from a loaded image where sprites are padded. More...
gfx_spritesheet_handle_t	gfxDrawLoadSpritesheetFromPortionOfImageUnpadded (gfx_image_handle_t img, unsigned sprite_cols, unsigned sprite_rows, unsigned sprite_width, unsigned sprite_height, unsigned bounding_box_left_x_pixel, unsigned bounding_box_top_y_pixel)
	Creates a spritesheet object from a portion of a loaded image where sprites are unpadded. More...
gfx_spritesheet_handle_t	gfxDrawLoadSpritesheetFromPortionOfImagePadded (gfx_image_handle_t img, unsigned sprite_cols, unsigned sprite_rows, unsigned sprite_width, unsigned sprite_height, unsigned sprite_padding_x, unsigned sprite_padding_y, unsigned bounding_box_left_x_pixel, unsigned bounding_box_top_y_pixel)
	Creates a spritesheet object from a portion of loaded image where sprites are padded. More...
gfx_spritesheet_handle_t	gfxDrawLoadSpritesheetFromPortionOfImagePaddedSpacing (gfx_image_handle_t img, unsigned sprite_cols, unsigned sprite_rows, unsigned sprite_width, unsigned sprite_height, unsigned sprite_spacing_x, unsigned sprite_spacing_y, unsigned bounding_box_left_x_pixel, unsigned bounding_box_top_y_pixel)
	Creates a spritesheet object from a portion of loaded image where sprites are padded. More...
int	gfxDrawSprite (gfx_spritesheet_handle_t spritesheet, char column, char row, signed short x, signed short y)
	Draws a sprite from a spritesheet. More...
int __attribute_deprecated__	gfxGetImageSize (char *filename, int *w, int *h)
	Gets the width and height of an image. More...
int __attribute_deprecated__	gfxDrawScaledImage (char *filename, signed short x, signed short y, float scale)
	Draws a scaled image on the screen. More...
int	gfxDrawArrow (signed short x1, signed short y1, signed short x2, signed short y2, signed short head_length, unsigned char thickness, unsigned int colour)
	Draws an arrow on the screen. More...
void	gfxDrawAnimationReset (gfx_sequence_handle_t sequence)
	Resets the time and frame of an animation back to its initial configuration. More...
int	gfxDrawAnimationDrawFrame (gfx_sequence_handle_t sequence, unsigned ms_timestep, int x, int y)
	Draws the target intantiated animation sequence at a given location. More...
int	gfxDrawSetGlobalXOffset (int offset)
	Sets the global draw position offset's X axis value. More...
int	gfxDrawSetGlobalYOffset (int offset)
	Sets the global draw position offset's Y axis value. More...
int	gfxDrawGetGlobalXOffset (int *offset)
	Retrieves a copy of the current global X axis drawing offset. More...
int	gfxDrawGetGlobalYOffset (int *offset)
	Retrieves a copy of the current global X axis drawing offset. More...

Variables
pthread_mutex_t	job_list_lock = PTHREAD_MUTEX_INITIALIZER
draw_job_t	job_list_head = { 0 }
struct global_offsets	global_offset
pthread_mutex_t	loaded_images_lock = PTHREAD_MUTEX_INITIALIZER
loaded_image_t	loaded_images_list = { 0 }
const int	screen_height = SCREEN_HEIGHT
const int	screen_width = SCREEN_WIDTH
SDL_Window *	window = NULL
SDL_Renderer *	renderer = NULL
SDL_GLContext	context = NULL
char *	error_message = NULL

Detailed Description

A SDL2 based library to implement work queue based drawing of graphical elements. Allows for drawing using SDL2 from multiple threads.

Author

Alex Hoffman

Date

27 August 2019

   ----------------------------------------------------------------------
    Copyright (C) Alexander Hoffman, 2019
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    any later version.
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
   ----------------------------------------------------------------------

Macro Definition Documentation

ALPHA_SOLID

#define ALPHA_SOLID   MAX_8_BIT

BLUE_PORTION

#define BLUE_PORTION

(

COLOUR

)

(COLOUR & 0x0000FF)

FIRST_BYTE

#define FIRST_BYTE   0x000000ff

FOURTH_BYTE

#define FOURTH_BYTE   0xff000000

GREEN_PORTION

#define GREEN_PORTION

(

COLOUR

)

(COLOUR & 0x00FF00) >> ONE_BYTE

INIT_JOB

#define INIT_JOB	(		JOB,
			TYPE
	)

Value:

    draw_job_t *JOB = _pushDrawJob();                                      \
    if (!JOB)                                                              \
        return -1;                                                     \
    union data_u *data = calloc(1, sizeof(union data_u));                  \
    if (data == NULL)                                                      \
        logCriticalError("job->data alloc");                           \
    JOB->data = data;                                                      \
    JOB->type = TYPE;

MAX_8_BIT

#define MAX_8_BIT   255

MS_IN_SECOND

#define MS_IN_SECOND   1000.0

NS_IN_MS

#define NS_IN_MS   1000000.0

NS_IN_SECOND

#define NS_IN_SECOND   1000000000.0

ONE_BYTE

#define ONE_BYTE   8

PRINT_SDL_ERROR

#define PRINT_SDL_ERROR	(		msg,
			...
	)

Value:

    PRINT_ERROR("[SDL Error] %s\n" #msg, (char *)SDL_GetError(),           \
                ##__VA_ARGS__)

RED_PORTION

#define RED_PORTION

(

COLOUR

)

(COLOUR & 0xFF0000) >> TWO_BYTES

SECOND_BYTE

#define SECOND_BYTE   0x0000ff00

THIRD_BYTE

#define THIRD_BYTE   0x00ff0000

THREE_BYTES

#define THREE_BYTES   24

TWO_BYTES

#define TWO_BYTES   16

ZERO_ALPHA

#define ZERO_ALPHA   0

Typedef Documentation

animated_image_t

typedef struct animated_image animated_image_t

animated_sequence_instance_t

typedef struct animated_sequence_instance animated_sequence_instance_t

arc_data_t

typedef struct arc_data arc_data_t

arrow_data_t

typedef struct arrow_data arrow_data_t

circle_data_t

typedef struct circle_data circle_data_t

clear_data_t

typedef struct clear_data clear_data_t

draw_job_t

typedef struct draw_job draw_job_t

ellipse_data_t

typedef struct ellipse_data ellipse_data_t

image_data_t

typedef struct image_data image_data_t

line_data_t

typedef struct line_data line_data_t

loaded_image_crop_t

typedef struct loaded_image_crop loaded_image_crop_t

loaded_image_data_t

typedef struct loaded_image_data loaded_image_data_t

loaded_image_t

typedef struct loaded_image loaded_image_t

poly_data_t

typedef struct poly_data poly_data_t

rect_data_t

typedef struct rect_data rect_data_t

scaled_image_data_t

typedef struct scaled_image_data scaled_image_data_t

spritesheet_sequence_t

typedef struct spritesheet_sequence spritesheet_sequence_t

spritesheet_t

typedef struct spritesheet spritesheet_t

text_data_t

typedef struct text_data text_data_t

triangle_data_t

typedef struct triangle_data triangle_data_t

Enumeration Type Documentation

draw_job_type_t

enum draw_job_type_t

Enumerator
DRAW_NONE
DRAW_CLEAR
DRAW_ARC
DRAW_ELLIPSE
DRAW_TEXT
DRAW_RECT
DRAW_FILLED_RECT
DRAW_CIRCLE
DRAW_LINE
DRAW_POLY
DRAW_TRIANGLE
DRAW_IMAGE
DRAW_LOADED_IMAGE
DRAW_LOADED_IMAGE_CROP
DRAW_SCALED_IMAGE
DRAW_ARROW

Function Documentation

_setErrorMessage()

void _setErrorMessage

(

char *

msg

)

gfxDrawInitSpritesheet()

spritesheet_t* gfxDrawInitSpritesheet

(

gfx_image_handle_t

img

)

gfxDrawSpritesheetSetBoundingBox()

void gfxDrawSpritesheetSetBoundingBox	(	spritesheet_t *	spritesheet,
		unsigned	bounding_x,
		unsigned	bounding_y,
		unsigned	bounding_w,
		unsigned	bounding_h
	)

gfxDrawSpritesheetSetDivisions()

void gfxDrawSpritesheetSetDivisions	(	spritesheet_t *	spritesheet,
		unsigned	cols,
		unsigned	rows
	)

Sets the number of cols and rows and in turn the sprite width and height. Should be called AFTER setting the padding and bounding box.

Parameters

spritesheet	Sprite sheet to be set
cols	Number of columns on the spritesheet
rows	Number of rows on the spritesheet

gfxDrawSpritesheetSetPadding()

void gfxDrawSpritesheetSetPadding	(	spritesheet_t *	spritesheet,
		unsigned	padding_x,
		unsigned	padding_y
	)

xDrawLoadedImage()

int xDrawLoadedImage	(	loaded_image_t *	img,
		SDL_Renderer *	ren,
		signed short	x,
		signed short	y
	)

xDrawLoadedImageCropped()

int xDrawLoadedImageCropped	(	loaded_image_t *	img,
		SDL_Renderer *	ren,
		signed short	x,
		signed short	y,
		signed short	c_x,
		signed short	c_y,
		signed short	c_w,
		signed short	c_h
	)

Variable Documentation

context

SDL_GLContext context = NULL

error_message

char* error_message = NULL

global_offset

struct global_offsets global_offset

Initial value:

= {
    .lock = PTHREAD_MUTEX_INITIALIZER,
}

job_list_head

draw_job_t job_list_head = { 0 }

job_list_lock

pthread_mutex_t job_list_lock = PTHREAD_MUTEX_INITIALIZER

loaded_images_list

loaded_image_t loaded_images_list = { 0 }

loaded_images_lock

pthread_mutex_t loaded_images_lock = PTHREAD_MUTEX_INITIALIZER

renderer

SDL_Renderer* renderer = NULL

screen_height

const int screen_height = SCREEN_HEIGHT

screen_width

const int screen_width = SCREEN_WIDTH

window

SDL_Window* window = NULL