Difference between revisions of "C Library Commands and How to Use Them"

From Learn @ Cemetech
Jump to navigationJump to search
Line 4: Line 4:
 
----
 
----
 
==Graphics Commands==
 
==Graphics Commands==
Here you will find all of the '''Graphx''' library commands
+
Here you will find all of the '''graphx''' library commands
 
----
 
----
 
===gfx_AllocSprite and gfx_GetSprite===
 
===gfx_AllocSprite and gfx_GetSprite===
Line 21: Line 21:
 
*width - The width of the sprite you want to decompress or create
 
*width - The width of the sprite you want to decompress or create
 
*height - The height of the sprite you want to decompress or create
 
*height - The height of the sprite you want to decompress or create
*malloc_routine - Not exactly sure what this does, just put ''malloc'' when writing the command
+
*malloc_routine - Usually you will put ''malloc'' for this argument; unless you are supplying a custom one.
  
 
'''gfx_GetSprite() In the graphx.h file:'''
 
'''gfx_GetSprite() In the graphx.h file:'''
Line 30: Line 30:
 
   * sprite_buffer is updated with the screen coordinates given.
 
   * sprite_buffer is updated with the screen coordinates given.
 
   */
 
   */
  gfx_image_t *gfx_GetSprite_NoClip(gfx_image_t *sprite_buffer, uint24_t x, uint8_t y);
+
  gfx_image_t *gfx_GetSprite_NoClip(gfx_image_t *sprite_buffer, int x, int y);
 
*sprite_buffer - The name of the sprite you want to create, the one defined with AllocSprite
 
*sprite_buffer - The name of the sprite you want to create, the one defined with AllocSprite
*x - The x position on teh screen to display the sprite
+
*x - The x position on the screen to display the sprite
 
*y - The y position on the screen to display the sprite
 
*y - The y position on the screen to display the sprite
  
 
Ok, so now we're going to show you how to use both commands. Check this example code out, to be explained afterwards.
 
Ok, so now we're going to show you how to use both commands. Check this example code out, to be explained afterwards.
//Make this a global:
+
 
  gfx_image_t *spriteName
+
  gfx_image_t *sprite;
 +
 
 
  malloc(0);
 
  malloc(0);
  spriteName = gfx_AllocSprite(30, 40, malloc);
+
  sprite = gfx_AllocSprite(30, 40, malloc);
  gfx_GetSprite(spriteName, 20, 50);
+
  gfx_GetSprite(sprite, 20, 50);
*'''gfx_image_t spriteName''' defines the sprite variable
+
 
*'''malloc(0);''' sets that ''malloc'' value to 0
+
*'''gfx_image_t spriteName''' declares a sprite variable
*'''spriteName = gfx_AllocSprite(30, 40, malloc);''' sets spriteName to the width and height of the next few values
+
*'''malloc( 0 );''' makes sure malloc is linked correctly. You only need to do this once.
*'''gfx_GetSprite(spriteName, 20, 50);''' grabs a sprite the dimensions of spriteName at x-20 and y-50, and sets it to spriteName, to be called later as a sprite
+
*'''spriteName = gfx_AllocSprite( 30, 40, malloc );''' sets the width and height of sprite
 +
*'''gfx_GetSprite( spriteName, 20, 50 );''' grabs a sprite at x = 20 and y = 50, and stores it in sprite for later use
 
----
 
----

Revision as of 00:41, 7 September 2016

Introduction


This guide will eventually list almost every C Library command in the SDK, and give a detailed explanation on how to use each one.


Graphics Commands

Here you will find all of the graphx library commands


gfx_AllocSprite and gfx_GetSprite


This command is useful to set room aside in the program for new sprites you will create with gfx_GetSprite and/or for sprites to need to decompress.

gfx_AllocSprite() In the graphx.h file:

/**
 * Allocates room on the heap for sprite data of given size
 * Takes a pointer to the routine used for malloc as well
 * Returns NULL upon failure to allocate space, otherwise a pointer to the sprite structure
 * Note that if you use the system malloc routine, it must be used elsewhere in your program
 * otherwise it will not be linked correctly
 */
gfx_image_t *gfx_AllocSprite(uint8_t width, uint8_t height, void *malloc_routine);
  • width - The width of the sprite you want to decompress or create
  • height - The height of the sprite you want to decompress or create
  • malloc_routine - Usually you will put malloc for this argument; unless you are supplying a custom one.

gfx_GetSprite() In the graphx.h file:

/**
 * Quickly grab the background behind a sprite (useful for transparency)
 * sprite_buffer must be pointing to a large enough buffer to hold width*height number of bytes
 * A pointer to sprite_buffer is also returned for ease of use.
 * sprite_buffer is updated with the screen coordinates given.
 */
gfx_image_t *gfx_GetSprite_NoClip(gfx_image_t *sprite_buffer, int x, int y);
  • sprite_buffer - The name of the sprite you want to create, the one defined with AllocSprite
  • x - The x position on the screen to display the sprite
  • y - The y position on the screen to display the sprite

Ok, so now we're going to show you how to use both commands. Check this example code out, to be explained afterwards.

gfx_image_t *sprite;
malloc(0);
sprite = gfx_AllocSprite(30, 40, malloc);
gfx_GetSprite(sprite, 20, 50);
  • gfx_image_t spriteName declares a sprite variable
  • malloc( 0 ); makes sure malloc is linked correctly. You only need to do this once.
  • spriteName = gfx_AllocSprite( 30, 40, malloc ); sets the width and height of sprite
  • gfx_GetSprite( spriteName, 20, 50 ); grabs a sprite at x = 20 and y = 50, and stores it in sprite for later use