rply.c

游戏编程精粹６中关于用自适度二叉树进行空间剖分

static int ply_read_scalar_property(p_ply ply, p_ply_element element, 
        p_ply_property property, p_ply_argument argument) {
    p_ply_read_cb read_cb = property->read_cb;
    p_ply_ihandler *driver = ply->idriver->ihandler; 
    p_ply_ihandler handler = driver[property->type];
    argument->length = 1;
    argument->value_index = 0;
    if (!handler(ply, &argument->value)) {
        ply_error(ply, "Error reading '%s' of '%s' number %d",
                property->name, element->name, argument->instance_index);
        return 0;
    }
    if (read_cb && !read_cb(argument)) {
        ply_error(ply, "Aborted by user");
        return 0;
    }
    return 1;
}

static int ply_read_property(p_ply ply, p_ply_element element, 
        p_ply_property property, p_ply_argument argument) {
    if (property->type == PLY_LIST) 
        return ply_read_list_property(ply, element, property, argument);
    else 
        return ply_read_scalar_property(ply, element, property, argument);
}

static int ply_read_element(p_ply ply, p_ply_element element, 
        p_ply_argument argument) {
    long j, k;
    /* for each element of this type */
    for (j = 0; j < element->ninstances; j++) {
        argument->instance_index = j;
        /* for each property */
        for (k = 0; k < element->nproperties; k++) {
            p_ply_property property = &element->property[k];
            argument->property = property;
            argument->pdata = property->pdata;
            argument->idata = property->idata;
            if (!ply_read_property(ply, element, property, argument))
                return 0;
        }
    }
    return 1;
}

static int ply_find_string(const char *item, const char* const list[]) {
    int i;
    assert(item && list);
    for (i = 0; list[i]; i++) 
        if (!strcmp(list[i], item)) return i;
    return -1;
}

static p_ply_element ply_find_element(p_ply ply, const char *name) {
    p_ply_element element;
    int i, nelements;
    assert(ply && name); 
    element = ply->element;
    nelements = ply->nelements;
    assert(element || nelements == 0); 
    assert(!element || nelements > 0); 
    for (i = 0; i < nelements; i++) 
        if (!strcmp(element[i].name, name)) return &element[i];
    return NULL;
}

static p_ply_property ply_find_property(p_ply_element element, 
        const char *name) {
    p_ply_property property;
    int i, nproperties;
    assert(element && name); 
    property = element->property;
    nproperties = element->nproperties;
    assert(property || nproperties == 0); 
    assert(!property || nproperties > 0); 
    for (i = 0; i < nproperties; i++) 
        if (!strcmp(property[i].name, name)) return &property[i];
    return NULL;
}

static int ply_check_word(p_ply ply) {
    if (strlen(BLINE(ply)) >= WORDSIZE) {
        ply_error(ply, "Word too long");
        return 0;
    }
    return 1;
}

static int ply_read_word(p_ply ply) {
    size_t t = 0;
    assert(ply && ply->fp && ply->io_mode == PLY_READ);
    /* skip leading blanks */
    while (1) {
        t = strspn(BFIRST(ply), " \n\r\t");
        /* check if all buffer was made of blanks */
        if (t >= BSIZE(ply)) {
            if (!BREFILL(ply)) {
                ply_error(ply, "Unexpected end of file");
                return 0;
            }
        } else break; 
    } 
    BSKIP(ply, t); 
    /* look for a space after the current word */
    t = strcspn(BFIRST(ply), " \n\r\t");
    /* if we didn't reach the end of the buffer, we are done */
    if (t < BSIZE(ply)) {
        ply->buffer_token = ply->buffer_first;
        BSKIP(ply, t);
        *BFIRST(ply) = '\0';
        BSKIP(ply, 1);
        return ply_check_word(ply);
    }
    /* otherwise, try to refill buffer */
    if (!BREFILL(ply)) {
        ply_error(ply, "Unexpected end of file");
        return 0;
    }
    /* keep looking from where we left */
    t += strcspn(BFIRST(ply) + t, " \n\r\t");
    /* check if the token is too large for our buffer */
    if (t >= BSIZE(ply)) {
        ply_error(ply, "Token too large");
        return 0;
    }
    /* we are done */
    ply->buffer_token = ply->buffer_first;
    BSKIP(ply, t);
    *BFIRST(ply) = '\0';
    BSKIP(ply, 1);
    return ply_check_word(ply);
}

static int ply_check_line(p_ply ply) {
    if (strlen(BLINE(ply)) >= LINESIZE) {
        ply_error(ply, "Line too long");
        return 0;
    }
    return 1;
}

static int ply_read_line(p_ply ply) {
    const char *end = NULL;
    assert(ply && ply->fp && ply->io_mode == PLY_READ);
    /* look for a end of line */
    end = strchr(BFIRST(ply), '\n');
    /* if we didn't reach the end of the buffer, we are done */
    if (end) {
        ply->buffer_token = ply->buffer_first;
        BSKIP(ply, end - BFIRST(ply));
        *BFIRST(ply) = '\0';
        BSKIP(ply, 1);
        return ply_check_line(ply);
    } else {
        end = ply->buffer + BSIZE(ply); 
        /* otherwise, try to refill buffer */
        if (!BREFILL(ply)) {
            ply_error(ply, "Unexpected end of file");
            return 0;
        }
    }
    /* keep looking from where we left */
    end = strchr(end, '\n');
    /* check if the token is too large for our buffer */
    if (!end) {
        ply_error(ply, "Token too large");
        return 0;
    }
    /* we are done */
    ply->buffer_token = ply->buffer_first;
    BSKIP(ply, end - BFIRST(ply));
    *BFIRST(ply) = '\0';
    BSKIP(ply, 1);
    return ply_check_line(ply);
}

static int ply_read_chunk(p_ply ply, void *anybuffer, size_t size) {
    char *buffer = (char *) anybuffer;
    size_t i = 0;
    assert(ply && ply->fp && ply->io_mode == PLY_READ);
    assert(ply->buffer_first <= ply->buffer_last);
    while (i < size) {
        if (ply->buffer_first < ply->buffer_last) {
            buffer[i] = ply->buffer[ply->buffer_first];
            ply->buffer_first++;
            i++;
        } else {
            ply->buffer_first = 0;
            ply->buffer_last = fread(ply->buffer, 1, BUFFERSIZE, ply->fp);
            if (ply->buffer_last <= 0) return 0;
        }
    }
    return 1;
}

static int ply_write_chunk(p_ply ply, void *anybuffer, size_t size) {
    char *buffer = (char *) anybuffer;
    size_t i = 0;
    assert(ply && ply->fp && ply->io_mode == PLY_WRITE);
    assert(ply->buffer_last <= BUFFERSIZE);
    while (i < size) {
        if (ply->buffer_last < BUFFERSIZE) {
            ply->buffer[ply->buffer_last] = buffer[i];
            ply->buffer_last++;
            i++;
        } else {
            ply->buffer_last = 0;
            if (fwrite(ply->buffer, 1, BUFFERSIZE, ply->fp) < BUFFERSIZE)
                return 0;
        }
    }
    return 1;
}

static int ply_write_chunk_reverse(p_ply ply, void *anybuffer, size_t size) {
    int ret = 0;
    ply_reverse(anybuffer, size);
    ret = ply_write_chunk(ply, anybuffer, size);
    ply_reverse(anybuffer, size);
    return ret;
}

static int ply_read_chunk_reverse(p_ply ply, void *anybuffer, size_t size) {
    if (!ply_read_chunk(ply, anybuffer, size)) return 0;
    ply_reverse(anybuffer, size);
    return 1;
}

static void ply_reverse(void *anydata, size_t size) {
    char *data = (char *) anydata;
    char temp;
    size_t i;
    for (i = 0; i < size/2; i++) {
        temp = data[i];
        data[i] = data[size-i-1];
        data[size-i-1] = temp;
    }
}

static void ply_init(p_ply ply) {
    ply->c = ' ';
    ply->element = NULL;
    ply->nelements = 0;
    ply->comment = NULL;
    ply->ncomments = 0;
    ply->obj_info = NULL;
    ply->nobj_infos = 0;
    ply->idriver = NULL;
    ply->odriver = NULL;
    ply->buffer[0] = '\0';
    ply->buffer_first = ply->buffer_last = ply->buffer_token = 0;
    ply->welement = 0;
    ply->wproperty = 0;
    ply->winstance_index = 0;
    ply->wlength = 0;
    ply->wvalue_index = 0;
}

static void ply_element_init(p_ply_element element) {
    element->name[0] = '\0';
    element->ninstances = 0;
    element->property = NULL;
    element->nproperties = 0; 
}

static void ply_property_init(p_ply_property property) {
    property->name[0] = '\0';
    property->type = -1;
    property->length_type = -1;
    property->value_type = -1;
    property->read_cb = (p_ply_read_cb) NULL;
    property->pdata = NULL;
    property->idata = 0;
}

static p_ply ply_alloc(void) {
    p_ply ply = (p_ply) malloc(sizeof(t_ply));
    if (!ply) return NULL;
    ply_init(ply);
    return ply;
}

static void *ply_grow_array(p_ply ply, void **pointer, 
        long *nmemb, long size) {
    void *temp = *pointer;
    long count = *nmemb + 1;
    if (!temp) temp = malloc(count*size);
    else temp = realloc(temp, count*size);
    if (!temp) {
        ply_error(ply, "Out of memory");
        return NULL;
    }
    *pointer = temp;
    *nmemb = count;
    return (char *) temp + (count-1) * size;
}

static p_ply_element ply_grow_element(p_ply ply) {
    p_ply_element element = NULL;
    assert(ply); 
    assert(ply->element || ply->nelements == 0); 
    assert(!ply->element || ply->nelements > 0); 
    element = (p_ply_element) ply_grow_array(ply, (void **) &ply->element, 
            &ply->nelements, sizeof(t_ply_element));
    if (!element) return NULL;
    ply_element_init(element);
    return element; 
}

static p_ply_property ply_grow_property(p_ply ply, p_ply_element element) {
    p_ply_property property = NULL;
    assert(ply);
    assert(element);
    assert(element->property || element->nproperties == 0);
    assert(!element->property || element->nproperties > 0);
    property = (p_ply_property) ply_grow_array(ply, 
            (void **) &element->property, 
            &element->nproperties, sizeof(t_ply_property));
    if (!property) return NULL;
    ply_property_init(property);
    return property;
}

static int ply_read_header_format(p_ply ply) {
    assert(ply && ply->fp && ply->io_mode == PLY_READ);
    if (strcmp(BWORD(ply), "format")) return 0;
    if (!ply_read_word(ply)) return 0;
    ply->storage_mode = ply_find_string(BWORD(ply), ply_storage_mode_list);
    if (ply->storage_mode == (e_ply_storage_mode) (-1)) return 0;
    if (ply->storage_mode == PLY_ASCII) ply->idriver = &ply_idriver_ascii;
    else if (ply->storage_mode == ply_arch_endian()) 
        ply->idriver = &ply_idriver_binary;
    else ply->idriver = &ply_idriver_binary_reverse;
    if (!ply_read_word(ply)) return 0;
    if (strcmp(BWORD(ply), "1.0")) return 0;
    if (!ply_read_word(ply)) return 0;
    return 1;
}

static int ply_read_header_comment(p_ply ply) {
    assert(ply && ply->fp && ply->io_mode == PLY_READ);
    if (strcmp(BWORD(ply), "comment")) return 0;
    if (!ply_read_line(ply)) return 0;
    if (!ply_add_comment(ply, BLINE(ply))) return 0;
    if (!ply_read_word(ply)) return 0;
    return 1;
}

static int ply_read_header_obj_info(p_ply ply) {
    assert(ply && ply->fp && ply->io_mode == PLY_READ);
    if (strcmp(BWORD(ply), "obj_info")) return 0;
    if (!ply_read_line(ply)) return 0;
    if (!ply_add_obj_info(ply, BLINE(ply))) return 0;
    if (!ply_read_word(ply)) return 0;
    return 1;
}

static int ply_read_header_property(p_ply ply) {
    p_ply_element element = NULL;
    p_ply_property property = NULL;
    /* make sure it is a property */
    if (strcmp(BWORD(ply), "property")) return 0;
    element = &ply->element[ply->nelements-1];
    property = ply_grow_property(ply, element);
    if (!property) return 0;
    /* get property type */
    if (!ply_read_word(ply)) return 0;
    property->type = ply_find_string(BWORD(ply), ply_type_list);
    if (property->type == (e_ply_type) (-1)) return 0;
    if (property->type == PLY_LIST) {
        /* if it's a list, we need the base types */
        if (!ply_read_word(ply)) return 0;
        property->length_type = ply_find_string(BWORD(ply), ply_type_list);
        if (property->length_type == (e_ply_type) (-1)) return 0;