SDL/test/testutils.c

/*
Copyright 1997-2022 Sam Lantinga
Copyright 2022 Collabora Ltd.
SPDX-License-Identifier: Zlib
*/

#include "testutils.h"

/*
 * Return the absolute path to def in the SDL_GetBasePath() if possible, or
 * the relative path to def on platforms that don't have a working
 * SDL_GetBasePath(). Free the result with SDL_free.
 *
 * Fails and returns NULL if out of memory.
 */
char *
GetNearbyFilename(const char *file)
{
    char *base;
    char *path;

    base = SDL_GetBasePath();

    if (base != NULL) {
        SDL_RWops *rw;
        size_t len = SDL_strlen(base) + SDL_strlen(file) + 1;

        path = SDL_malloc(len);

        if (path == NULL) {
            SDL_free(base);
            SDL_OutOfMemory();
            return NULL;
        }

        (void)SDL_snprintf(path, len, "%s%s", base, file);
        SDL_free(base);

        rw = SDL_RWFromFile(path, "rb");
        if (rw) {
            SDL_RWclose(rw);
            return path;
        }

        /* Couldn't find the file in the base path */
        SDL_free(path);
    }

    path = SDL_strdup(file);
    if (path == NULL) {
        SDL_OutOfMemory();
    }
    return path;
}

/*
 * If user_specified is non-NULL, return a copy of it. Free with SDL_free.
 *
 * Otherwise, return the absolute path to def in the SDL_GetBasePath() if
 * possible, or the relative path to def on platforms that don't have a
 * working SDL_GetBasePath(). Free the result with SDL_free.
 *
 * Fails and returns NULL if out of memory.
 */
char *
GetResourceFilename(const char *user_specified, const char *def)
{
    if (user_specified != NULL) {
        char *ret = SDL_strdup(user_specified);

        if (ret == NULL) {
            SDL_OutOfMemory();
        }

        return ret;
    } else {
        return GetNearbyFilename(def);
    }
}

/*
 * Load the .bmp file whose name is file, from the SDL_GetBasePath() if
 * possible or the current working directory if not.
 *
 * If transparent is true, set the transparent colour from the top left pixel.
 *
 * If width_out is non-NULL, set it to the texture width.
 *
 * If height_out is non-NULL, set it to the texture height.
 */
SDL_Texture *
LoadTexture(SDL_Renderer *renderer, const char *file, SDL_bool transparent,
            int *width_out, int *height_out)
{
    SDL_Surface *temp = NULL;
    SDL_Texture *texture = NULL;
    char *path;

    path = GetNearbyFilename(file);

    if (path != NULL) {
        file = path;
    }

    temp = SDL_LoadBMP(file);
    if (temp == NULL) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s", file, SDL_GetError());
    } else {
        /* Set transparent pixel as the pixel at (0,0) */
        if (transparent) {
            if (temp->format->palette) {
                SDL_SetSurfaceColorKey(temp, SDL_TRUE, *(Uint8 *)temp->pixels);
            } else {
                switch (temp->format->BitsPerPixel) {
                case 15:
                    SDL_SetSurfaceColorKey(temp, SDL_TRUE,
                                    (*(Uint16 *)temp->pixels) & 0x00007FFF);
                    break;
                case 16:
                    SDL_SetSurfaceColorKey(temp, SDL_TRUE, *(Uint16 *)temp->pixels);
                    break;
                case 24:
                    SDL_SetSurfaceColorKey(temp, SDL_TRUE,
                                    (*(Uint32 *)temp->pixels) & 0x00FFFFFF);
                    break;
                case 32:
                    SDL_SetSurfaceColorKey(temp, SDL_TRUE, *(Uint32 *)temp->pixels);
                    break;
                }
            }
        }

        if (width_out != NULL) {
            *width_out = temp->w;
        }

        if (height_out != NULL) {
            *height_out = temp->h;
        }

        texture = SDL_CreateTextureFromSurface(renderer, temp);
        if (texture == NULL) {
            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create texture: %s\n", SDL_GetError());
        }
    }
    SDL_DestroySurface(temp);
    if (path) {
        SDL_free(path);
    }
    return texture;
}