libakgl/src/util.c

#include <limits.h>
#include <stdlib.h>
#include <errno.h>
#include <libgen.h>

#include <SDL3/SDL.h>
#include <SDL3_image/SDL_image.h>
#include <akerror.h>

#include <akgl/util.h>
#include <akgl/heap.h>
#include <akgl/registry.h>
#include <akgl/game.h>
#include <akgl/staticstring.h>

#include <akstdlib.h>

akerr_ErrorContext *akgl_path_relative_root(char *root, char *path, akgl_String *dst)
{
    PREPARE_ERROR(e);
    akgl_String *pathbuf;
    akgl_String *strbuf;
    char *result;
    int rootlen;
    int pathlen;
    int count;
    
    FAIL_ZERO_RETURN(e, root, AKERR_NULLPOINTER, "NULL argument");
    FAIL_ZERO_RETURN(e, path, AKERR_NULLPOINTER, "NULL argument");
    FAIL_ZERO_RETURN(e, dst, AKERR_NULLPOINTER, "NULL argument");

    PASS(e, akgl_heap_next_string(&strbuf));
    PASS(e, akgl_heap_next_string(&pathbuf));
    
    ATTEMPT {
	// Is it relative to the root?
	rootlen = strlen(root);
	pathlen = strlen(path);
	if ( (rootlen + pathlen) >= AKGL_MAX_STRING_LENGTH ) {
	    FAIL_RETURN(e, AKERR_OUTOFBOUNDS, "Total path length (%d) is greater than maximum akgl_String length (%d)", (rootlen + pathlen), AKGL_MAX_STRING_LENGTH);
	}
	DISABLE_GCC_WARNING_FORMAT_TRUNCATION
	CATCH(e, aksl_sprintf(&count, (char *)&pathbuf->data, "%s/%s", root, path));
	RESTORE_GCC_WARNINGS
	CATCH(e, aksl_realpath((char *)&pathbuf->data, (char *)&strbuf->data));
	CATCH(e, akgl_string_copy(strbuf, dst, 0)); 
    } CLEANUP {
	IGNORE(akgl_heap_release_string(strbuf));
	IGNORE(akgl_heap_release_string(pathbuf));
    } PROCESS(e) {
    } FINISH(e, true);
    SUCCEED_RETURN(e);
}

akerr_ErrorContext *akgl_path_relative(char *root, char *path, akgl_String *dst)
{
    PREPARE_ERROR(e);
    akgl_String *strbuf;
    char *result;
    
    FAIL_ZERO_RETURN(e, root, AKERR_NULLPOINTER, "NULL argument");
    FAIL_ZERO_RETURN(e, path, AKERR_NULLPOINTER, "NULL argument");
    FAIL_ZERO_RETURN(e, dst, AKERR_NULLPOINTER, "NULL argument");

    PASS(e, akgl_heap_next_string(&strbuf));
    
    ATTEMPT {
	// Is path relative to our current working directory?
	CATCH(e, aksl_realpath(path, (char *)&strbuf->data));
	// Yes it is. strbuf->data contains the absolute path.
	CATCH(e, akgl_string_copy(strbuf, dst, 0)); 
    } CLEANUP {
	IGNORE(akgl_heap_release_string(strbuf));
    } PROCESS(e) {
    } HANDLE(e, ENOENT) {
	// Path is not relative to our current working directory
	// Noop - execution proceeds after the break
	return akgl_path_relative_root(root, path, dst);
    } FINISH(e, true);
    SUCCEED_RETURN(e);
}

akerr_ErrorContext *akgl_path_relative_from(char *path, char *from, akgl_String **dst)
{
    akgl_String *dirnamestr;
    PREPARE_ERROR(e);
    FAIL_ZERO_RETURN(e, path, AKERR_NULLPOINTER, "path");
    FAIL_ZERO_RETURN(e, from, AKERR_NULLPOINTER, "from");
    PASS(e, akgl_heap_next_string(&dirnamestr));
    PASS(e, aksl_realpath(from, (char *)&dirnamestr->data));
    dirname((char *)&dirnamestr->data);
    
    SUCCEED_RETURN(e);
}

akerr_ErrorContext *akgl_rectangle_points(RectanglePoints *dest, SDL_FRect *rect)
{
  PREPARE_ERROR(errctx);
  FAIL_ZERO_RETURN(errctx, dest, AKERR_NULLPOINTER, "NULL RectanglePoints reference");
  FAIL_ZERO_RETURN(errctx, rect, AKERR_NULLPOINTER, "NULL Rectangle reference");
  dest->topleft.x = rect->x;
  dest->topleft.y = rect->y;
  dest->bottomleft.x = rect->x;
  dest->bottomleft.y = rect->y + rect->h;
  dest->topright.x = rect->x + rect->w;
  dest->topright.y = rect->y;
  dest->bottomright.x = rect->x + rect->w;
  dest->bottomright.y = rect->y + rect->h;
  SUCCEED_RETURN(errctx);
}

akerr_ErrorContext *akgl_collide_point_rectangle(point *p, RectanglePoints *rp, bool *collide)
{
  PREPARE_ERROR(errctx);
  FAIL_ZERO_RETURN(errctx, p, AKERR_NULLPOINTER, "NULL Point reference");
  FAIL_ZERO_RETURN(errctx, rp, AKERR_NULLPOINTER, "NULL RectanglePoints reference");
  FAIL_ZERO_RETURN(errctx, collide, AKERR_NULLPOINTER, "NULL boolean reference");
  if ( (p->x >= rp->topleft.x) && (p->y >= rp->topleft.y) &&
       (p->x <= rp->bottomright.x) && (p->y <= rp->bottomright.y) ) {
    *collide = true;
  } else {
    *collide = false;
  }
  SUCCEED_RETURN(errctx);
}

akerr_ErrorContext *akgl_collide_rectangles(SDL_FRect *r1, SDL_FRect *r2, bool *collide)
{
  RectanglePoints r1p;
  RectanglePoints r2p;
  PREPARE_ERROR(errctx);
  FAIL_ZERO_RETURN(errctx, r1, AKERR_NULLPOINTER, "NULL rectangle reference");
  FAIL_ZERO_RETURN(errctx, r2, AKERR_NULLPOINTER, "NULL rectangle reference");
  FAIL_ZERO_RETURN(errctx, collide, AKERR_NULLPOINTER, "NULL collision flag reference");
  
  ATTEMPT {
    CATCH(errctx, akgl_rectangle_points(&r1p, r1));
    CATCH(errctx, akgl_rectangle_points(&r2p, r2));
  
    // is the upper left corner of r1 contacting r2?
    CATCH(errctx, akgl_collide_point_rectangle(&r1p.topleft, &r2p, collide));
    if ( *collide == true  ) { SUCCEED_RETURN(errctx); }
    
    // is the upper left corner of r2 contacting r1?
    CATCH(errctx, akgl_collide_point_rectangle(&r2p.topleft, &r1p, collide));
    if ( *collide == true ) { SUCCEED_RETURN(errctx); }
    
    // is the top right corner of r1 contacting r2?
    CATCH(errctx, akgl_collide_point_rectangle(&r1p.topright, &r2p, collide));
    if ( *collide == true ) { SUCCEED_RETURN(errctx); }
    
    // is the top right corner of r2 contacting r1?
    CATCH(errctx, akgl_collide_point_rectangle(&r2p.topright, &r1p, collide));
    if ( *collide == true ) { SUCCEED_RETURN(errctx); }
    
    // is the bottom left corner of r1 contacting r2?
    CATCH(errctx, akgl_collide_point_rectangle(&r1p.bottomleft, &r2p, collide));
    if ( *collide == true ) { SUCCEED_RETURN(errctx); }
    
    // is the bottom left corner of r2 contacting r1?
    CATCH(errctx, akgl_collide_point_rectangle(&r2p.bottomleft, &r1p, collide));
    if ( *collide == true ) { SUCCEED_RETURN(errctx); }
    
    // is the bottom right corner of r1 contacting r2?
    CATCH(errctx, akgl_collide_point_rectangle(&r1p.bottomright, &r2p, collide));
    if ( *collide == true ) { SUCCEED_RETURN(errctx); }
    
    // is the bottom right corner of r2 contacting r1?
    CATCH(errctx, akgl_collide_point_rectangle(&r2p.bottomright, &r1p, collide));
    if ( *collide == true ) { SUCCEED_RETURN(errctx); }

  } CLEANUP {
  } PROCESS(errctx) {
  } FINISH(errctx, true);
  
  *collide = false;
  SUCCEED_RETURN(errctx);
}


akerr_ErrorContext *akgl_compare_sdl_surfaces(SDL_Surface *s1, SDL_Surface *s2)
{
  PREPARE_ERROR(errctx);
  FAIL_ZERO_RETURN(errctx, s1, AKERR_NULLPOINTER, "NULL Surface pointer");
  FAIL_ZERO_RETURN(errctx, s2, AKERR_NULLPOINTER, "NULL Surface pointer");
  FAIL_NONZERO_RETURN(errctx, memcmp(s1->pixels, s2->pixels, (s1->pitch * s1->h)), AKERR_VALUE, "Comparison surfaces are not equal");
  SUCCEED_RETURN(errctx);
}

akerr_ErrorContext *akgl_render_and_compare(SDL_Texture *t1, SDL_Texture *t2, int x, int y, int w, int h, char *writeout)
{
    SDL_Surface *s1 = NULL;
    SDL_Surface *s2 = NULL;
    SDL_FRect src = {.x = x, .y = y, .w = w, .h = h};
    SDL_FRect dest = {.x = x, .y = y, .w = w, .h = h};
    SDL_Rect read = {.x = x, .y = y, .w = w, .h = h};
    akgl_String *tmpstring = NULL;

    PREPARE_ERROR(errctx);
    ATTEMPT {
	FAIL_ZERO_BREAK(errctx, t1, AKERR_NULLPOINTER, "NULL texture");
	FAIL_ZERO_BREAK(errctx, t2, AKERR_NULLPOINTER, "NULL texture");

	CATCH(errctx, akgl_heap_next_string(&tmpstring));
	SDL_RenderClear(renderer.sdl_renderer);
	CATCH(errctx, renderer.draw_texture(&renderer, t1, &src, &dest, 0, NULL, SDL_FLIP_NONE));
	s1 = SDL_RenderReadPixels(renderer.sdl_renderer, &read);
	FAIL_ZERO_BREAK(errctx, s1, AKGL_ERR_SDL, "Failed to read pixels from renderer");
	
	if ( writeout != NULL ) {
	    snprintf((char *)&tmpstring->data, AKGL_MAX_STRING_LENGTH, "%s%s", SDL_GetBasePath(), writeout);
	    FAIL_ZERO_BREAK(
		errctx,
		IMG_SavePNG(s1, (char *)&tmpstring->data),
		AKERR_IO,
		"Unable to save %s: %s",
		(char *)&tmpstring->data,
		SDL_GetError());
	}
	
	SDL_RenderClear(renderer.sdl_renderer);
	
	CATCH(errctx, renderer.draw_texture(&renderer, t1, &src, &dest, 0, NULL, SDL_FLIP_NONE));
	s2 = SDL_RenderReadPixels(renderer.sdl_renderer, &read);
	FAIL_ZERO_BREAK(errctx, s2, AKGL_ERR_SDL, "Failed to read pixels from renderer");
	
	CATCH(errctx, akgl_compare_sdl_surfaces(s1, s2));
    } CLEANUP {
	if ( s1 != NULL )
	    SDL_DestroySurface(s1);
	if ( s2 != NULL )
	    SDL_DestroySurface(s2);
	IGNORE(akgl_heap_release_string(tmpstring));
    } PROCESS(errctx) {
    } FINISH(errctx, true);
    SUCCEED_RETURN(errctx);
}