masker: tga_v4.h

#ifndef __TGAH
#define __TGAH

#define __TGAH_verbose 0

#include <inttypes.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

/* 17-Oct-2018  added a way to make a new TGA with the same settings as an existing tga */
/* 18-Oct-2018  added rect data type and blit function */
/* 29-Jan-2021  added _t to pixel types, tga_free now returns a pointer */
/* 18-Nov-2023  added support for 8bpp grayscale TGAs */
/* 31-Mar-2024  moved from color structs to uint32_t color */
/* 10-Oct-2024  added line drawing to the base library */
/* 26-Oct-2024  added optimized 8bpp-specific functions */

/*
simple TGA header
  /---------------- uint8_t  pixel type, 2 for direct RGB
  |     /---------- int16_t  X origin, pretty much always 0
  |     | /-------- int16_t  Y origin, pretty much always == height
  |     | | /------ uint16_t width
  |     | | | /---- uint16_t height
  |     | | | | /-- uint8_t  bits-per-pixel
  |     | | | | |/- uint8_t  bit-field: 00S0BBBB   B=bits per alpha  S=screen origin
  |     | | | | ||
00P00000XXYYWWHHBC

RGBA values are stored as BGRA
*/

typedef uint32_t color_t;

#ifndef __sdl_gen_h
// The 8 digital colors
#define c_black  (0x000000FF)
#define c_blue   (0x0000FFFF)
#define c_green  (0x00FF00FF)
#define c_cyan   (0x00FFFFFF)
#define c_red    (0xFF0000FF)
#define c_pink   (0xFF00FFFF)
#define c_yellow (0xFFFF00FF)
#define c_white  (0xFFFFFFFF)

// various shades of gray
#define c_gray   (0xBCBCBCFF)
#define c_gray25 (0x808080FF)
#define c_gray50 (0x404040FF)
#endif

typedef struct tga_t      tga_t;
typedef struct tga_rect_t tga_rect_t;
typedef struct tga_info_t tga_info_t;

struct tga_rect_t {
    int16_t  x;
    int16_t  y;
    uint16_t w;
    uint16_t h;
};

struct tga_info_t {
    tga_rect_t rect;
    _Bool inverted;
    uint8_t pixel_type, bits_per_pixel, bits_per_alpha;
};

struct tga_t { /*  P=pixel type X=x origin Y=y origin W=width H=height B=bpp A=bpa */
    uint16_t w;              // width
    uint16_t h;              // height
    uint8_t  bpp;            // bits per pixel (always 24 or 32, or 8 for grayscale)
    uint8_t* pixels;         // either RGB8 or RGBA8, or Y8
    uint8_t  ext_pixels  :1; // if set, the pixel buffer is external and shouldn't be freed
    uint8_t  inverted    :1; // if set, the image is stored upside down
    size_t   refcount;
};

// color_t tga_new_color( uint8_t r, uint8_t g, uint8_t b, uint8_t a );
#define tga_new_color( r, g, b, a )    ( ((((color_t)(r))<<24)&0xFF000000) | ((((color_t)(g))<<16)&0xFF0000) | ((((color_t)(b))<<8)&0xFF00) | (((color_t)(a))&0xFF) )

color_t tga_new_color_from_shade( uint8_t s );

// make a new TGA
tga_t* tga_new( uint16_t w, uint16_t h, uint8_t bpp );

// to make a new TGA with the same size, pass 0 to w and h
tga_t* tga_new_formatted( uint16_t w, uint16_t h, tga_t* tga_ref );


tga_t* tga_new_from_data( uint16_t w, uint16_t h, uint8_t bpp, uint8_t inverted, uint8_t* data );

tga_t* tga_free( tga_t* t ); // frees a TGA

color_t tga_pixel_get( tga_t* t, uint16_t x, uint16_t y );
void  tga_pixel_set( tga_t* t, uint16_t x, uint16_t y, color_t c );

uint8_t tga_pixel_get8( tga_t* t, uint16_t x, uint32_t y );
void tga_pixel_set8( tga_t* t, uint16_t x, uint32_t y, uint8_t c );

// returns 0 on success, -1 on failure
int tga_blit( tga_t* source, tga_t* dest, tga_rect_t rect_src, tga_rect_t rect_dest );
int tga_blit_simple( tga_t* source, tga_t* dest, int dest_x, int dest_y );
int tga_blit_simple_fast( tga_t* source, tga_t* dest );

int tga_rect_fill( tga_t* img, tga_rect_t rect, color_t c );
int tga_fill( tga_t* img, color_t c );

int tga_fill8( tga_t* img, uint8_t c );

void tga_line( int32_t x0, int32_t y0, int32_t x1, int32_t y1, color_t color, tga_t* tga );
void tga_line_thick( int32_t x0, int32_t y0, int32_t x1, int32_t y1, color_t color, tga_t* tga );

void tga_circle(        tga_t* tga, int x0, int y0, int radius, color_t color );
void tga_circle_filled( tga_t* tga, int x0, int y0, int radius, color_t color );

void tga_copy( tga_t* source, tga_t* dest );

tga_t* tga_load( char* fname );
void   tga_save( char* fname, tga_t* t );
void print_tga_info( tga_t* t );

void tga_vflip( tga_t* t );

tga_info_t tga_load_info( char* fname );
#define tga_info_bad( tga_info )  ((tga_info).rect.w == 0)

#endif