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/*
* This file is part of librosprite.
* Licensed under the MIT License,
* http://www.opensource.org/licenses/mit-license.php
* Copyright 2008 James Shaw <js102@zepler.net>
*/
/**
* \mainpage
*
* librosprite is a library for reading RISC OS sprite and palette files. The following subformats are supported:
* <ul>
* <li>1-bit and 8-bit transparency masks</li>
* <li>Sprites with custom palettes</li>
* <li>Standard RISC OS 1-bit, 2-bit palettes, and 4-bit and 8-bit colour palettes</li>
* <li>Old-style sprites with most screen modes from 0-49 supported</li>
* <li>32bpp CMYK</li>
* <li>Inline alpha channel, as used by Photodesk and Tinct</li>
* </ul>
*
*/
/**
* \file librosprite.h
*
* Sprite file reading is performed by rosprite_load(), and palette file reading by rosprite_load_palette().
*
* Retrieving sprite or palette data is performed by a reader.
* librosprite implements file and memory readers.
* To use a reader, create a context by calling the
* rosprite_create_file_context() or rosprite_create_mem_context().
* Pass the reader function, and the context you have created, to the load function,
* typically rosprite_load().
*/
#ifndef ROSPRITE_H
#define ROSPRITE_H
#include <stdint.h>
#include <stdio.h>
#include <stdbool.h>
typedef enum { ROSPRITE_OK, ROSPRITE_NOMEM, ROSPRITE_EOF, ROSPRITE_BADMODE } rosprite_error;
typedef enum { ROSPRITE_RGB, ROSPRITE_CMYK } rosprite_color_model;
/**
* A reader interface used to load sprite files.
*/
typedef int (*reader)(uint8_t* buf, size_t count, void* ctx);
struct rosprite_file_context;
/**
* A sprite area comprises zero or more rosprites. Optionally, it may also have an extension_words block.
*/
struct rosprite_area {
uint32_t extension_size; /* size of extension_words in bytes */
uint8_t* extension_words;
uint32_t sprite_count;
struct rosprite** sprites; /* array of length sprite_count */
};
/**
* A sprite mode defines the colour depth, colour model and bitmap resolution of a sprite.
*/
struct rosprite_mode {
/**
* The bits per colour channel. Legal values are 1, 2, 4, 8, 16, 24 and 32.
*/
uint32_t colorbpp;
/* maskbpp denotes the amount of alpha bpp used
* while mask_width is the bits used to store the mask.
* Old modes have the same mask_width as their colorbpp, but the value
* is always all-zeroes or all-ones.
* New modes can have 1bpp or 8bpp masks
*/
uint32_t maskbpp;
uint32_t mask_width; /* in pixels */
/**
* Horizontal dots per inch. Typical values are 22, 45, 90 and 180.
*/
uint32_t xdpi;
/**
* Vertical dots per inch. Typical values are 22, 45, 90 and 180.
*/
uint32_t ydpi;
rosprite_color_model color_model;
};
struct rosprite_palette {
uint32_t size; /* in number of entries (each entry is a word) */
uint32_t* palette;
};
/**
* A sprite is a bitmap image which has a mode, width and height.
*/
struct rosprite {
/**
* The sprite name. This may be up to 12 characters long, and must be zero terminated.
*/
unsigned char name[13];
struct rosprite_mode mode;
bool has_mask;
bool has_palette;
uint32_t palettesize; /* in number of entries (each entry is a word) */
uint32_t* palette;
/**
* Width in pixels
*/
uint32_t width;
/**
* Height in pixels
*/
uint32_t height;
/**
* Image data is a series of words, appearing on screen left-to-right, top-to-bottom.
* Each word takes the form 0xRRGGBBAA. A is the alpha channel, where 0 is transparent, and 255 is opaque.
*/
uint32_t* image; /* image data in 0xRRGGBBAA words */
};
struct rosprite_file_context;
/**
* Create a file reader context using the specified file handle.
* Clients must call rosprite_destroy_file_context() to dispose of the context.
*
* \param[out] result
*/
rosprite_error rosprite_create_file_context(FILE* f, struct rosprite_file_context** result);
void rosprite_destroy_file_context(struct rosprite_file_context* ctx);
int rosprite_file_reader(uint8_t* buf, size_t count, void* ctx);
struct rosprite_mem_context;
/**
* Create a memory reader context using the specified memory pointer.
* Clients must call rosprite_destroy_mem_context() to dispose of the context.
*
* \param[in] p pointer to the start of the memory block
* \param[in] total_size the size of the block pointed to by p, in bytes
* \param[out] result
*/
rosprite_error rosprite_create_mem_context(uint8_t* p, unsigned long total_size, struct rosprite_mem_context** result);
void rosprite_destroy_mem_context(struct rosprite_mem_context* ctx);
int rosprite_mem_reader(uint8_t* buf, size_t count, void* ctx);
/**
* Load a rosprite_area using the reader provided.
* Clients must call rosprite_destroy_sprite_area() to dispose of the rosprite_area.
*
* \param[out] result The pointer to be populated by this function.
*/
rosprite_error rosprite_load(reader reader, void* ctx, struct rosprite_area** result);
/**
* Dispose of a rosprite_area and its children.
*/
void rosprite_destroy_sprite_area(struct rosprite_area *);
/**
* Load a RISC OS palette file. A palette file has RISC OS filetype 0xFED,
* and is a series of VDU 19 Set Palette commands, each command being 6 bytes long.
*
* Clients must call rosprite_destroy_palette() to dispose of the rosprite_palette.
*
* \param[out] result The pointer to be populated by this function.
* \see http://www.drobe.co.uk/show_manual.php?manual=/sh-cgi?manual=Vdu%26page=19
*/
rosprite_error rosprite_load_palette(reader reader, void* ctx, struct rosprite_palette** result);
/**
* Dispose of a rosprite_palette and its children.
*/
void rosprite_destroy_palette(struct rosprite_palette *);
#endif
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