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

 * Write support functions
 * ---------------------------------------------------------------------- */
p_ply ply_create(const char *name, e_ply_storage_mode storage_mode, 
        p_ply_error_cb error_cb) {
    FILE *fp = NULL;
    p_ply ply = NULL;
    if (error_cb == NULL) error_cb = ply_error_cb;
    if (!ply_type_check()) {
        error_cb("Incompatible type system");
        return NULL;
    }
    assert(name && storage_mode <= PLY_DEFAULT);
    fp = fopen(name, "wb");
    if (!fp) {
        error_cb("Unable to create file");
        return NULL;
    }
    ply = ply_alloc();
    if (!ply) {
        fclose(fp);
        error_cb("Out of memory");
        return NULL;
    }
    ply->io_mode = PLY_WRITE;
    if (storage_mode == PLY_DEFAULT) storage_mode = ply_arch_endian();
    if (storage_mode == PLY_ASCII) ply->odriver = &ply_odriver_ascii;
    else if (storage_mode == ply_arch_endian()) 
        ply->odriver = &ply_odriver_binary;
    else ply->odriver = &ply_odriver_binary_reverse;
    ply->storage_mode = storage_mode;
    ply->fp = fp;
    ply->error_cb = error_cb;
    return ply;
}

int ply_add_element(p_ply ply, const char *name, long ninstances) {
    p_ply_element element = NULL;
    assert(ply && ply->fp && ply->io_mode == PLY_WRITE);
    assert(name && strlen(name) < WORDSIZE && ninstances >= 0);
    if (strlen(name) >= WORDSIZE || ninstances < 0) {
        ply_error(ply, "Invalid arguments");
        return 0;
    }
    element = ply_grow_element(ply);
    if (!element) return 0;
    strcpy(element->name, name);
    element->ninstances = ninstances;
    return 1;
}

int ply_add_scalar_property(p_ply ply, const char *name, e_ply_type type) {
    p_ply_element element = NULL;
    p_ply_property property = NULL;
    assert(ply && ply->fp && ply->io_mode == PLY_WRITE);
    assert(name && strlen(name) < WORDSIZE);
    assert(type < PLY_LIST);
    if (strlen(name) >= WORDSIZE || type >= PLY_LIST) {
        ply_error(ply, "Invalid arguments");
        return 0;
    }
    element = &ply->element[ply->nelements-1];
    property = ply_grow_property(ply, element);
    if (!property) return 0;
    strcpy(property->name, name);
    property->type = type;
    return 1;
}

int ply_add_list_property(p_ply ply, const char *name, 
        e_ply_type length_type, e_ply_type value_type) {
    p_ply_element element = NULL;
    p_ply_property property = NULL;
    assert(ply && ply->fp && ply->io_mode == PLY_WRITE);
    assert(name && strlen(name) < WORDSIZE);
    if (strlen(name) >= WORDSIZE) {
        ply_error(ply, "Invalid arguments");
        return 0;
    }
    assert(length_type < PLY_LIST);
    assert(value_type < PLY_LIST);
    if (length_type >= PLY_LIST || value_type >= PLY_LIST) {
        ply_error(ply, "Invalid arguments");
        return 0;
    }
    element = &ply->element[ply->nelements-1];
    property = ply_grow_property(ply, element);
    if (!property) return 0;
    strcpy(property->name, name);
    property->type = PLY_LIST;
    property->length_type = length_type;
    property->value_type = value_type;
    return 1;
}

int ply_add_property(p_ply ply, const char *name, e_ply_type type,
        e_ply_type length_type, e_ply_type value_type) {
    if (type == PLY_LIST) 
        return ply_add_list_property(ply, name, length_type, value_type);
    else 
        return ply_add_scalar_property(ply, name, type);
}

int ply_add_comment(p_ply ply, const char *comment) {
    char *new_comment = NULL;
    assert(ply && comment && strlen(comment) < LINESIZE);
    if (!comment || strlen(comment) >= LINESIZE) {
        ply_error(ply, "Invalid arguments");
        return 0;
    }
    new_comment = (char *) ply_grow_array(ply, (void **) &ply->comment,
            &ply->ncomments, LINESIZE);
    if (!new_comment) return 0;
    strcpy(new_comment, comment);
    return 1;
}

int ply_add_obj_info(p_ply ply, const char *obj_info) {
    char *new_obj_info = NULL;
    assert(ply && obj_info && strlen(obj_info) < LINESIZE);
    if (!obj_info || strlen(obj_info) >= LINESIZE) {
        ply_error(ply, "Invalid arguments");
        return 0;
    }
    new_obj_info = (char *) ply_grow_array(ply, (void **) &ply->obj_info,
            &ply->nobj_infos, LINESIZE);
    if (!new_obj_info) return 0;
    strcpy(new_obj_info, obj_info);
    return 1;
}

int ply_write_header(p_ply ply) {
    long i, j;
    assert(ply && ply->fp && ply->io_mode == PLY_WRITE);
    assert(ply->element || ply->nelements == 0); 
    assert(!ply->element || ply->nelements > 0); 
    if (fprintf(ply->fp, "ply\nformat %s 1.0\n", 
                ply_storage_mode_list[ply->storage_mode]) <= 0) goto error;
    for (i = 0; i < ply->ncomments; i++)
        if (fprintf(ply->fp, "comment %s\n", ply->comment + LINESIZE*i) <= 0)
            goto error;
    for (i = 0; i < ply->nobj_infos; i++)
        if (fprintf(ply->fp, "obj_info %s\n", ply->obj_info + LINESIZE*i) <= 0)
            goto error;
    for (i = 0; i < ply->nelements; i++) {
        p_ply_element element = &ply->element[i];
        assert(element->property || element->nproperties == 0); 
        assert(!element->property || element->nproperties > 0); 
        if (fprintf(ply->fp, "element %s %ld\n", element->name, 
                    element->ninstances) <= 0) goto error;
        for (j = 0; j < element->nproperties; j++) {
            p_ply_property property = &element->property[j];
            if (property->type == PLY_LIST) {
                if (fprintf(ply->fp, "property list %s %s %s\n", 
                            ply_type_list[property->length_type],
                            ply_type_list[property->value_type],
                            property->name) <= 0) goto error;
            } else {
                if (fprintf(ply->fp, "property %s %s\n", 
                            ply_type_list[property->type],
                            property->name) <= 0) goto error;
            }
        }
    }
    return fprintf(ply->fp, "end_header\n") > 0;
error:
    ply_error(ply, "Error writing to file");
    return 0;
}

int ply_write(p_ply ply, double value) {
    p_ply_element element = NULL;
    p_ply_property property = NULL;
    int type = -1;
    int breakafter = 0;
    if (ply->welement > ply->nelements) return 0;
    element = &ply->element[ply->welement];
    if (ply->wproperty > element->nproperties) return 0;
    property = &element->property[ply->wproperty];
    if (property->type == PLY_LIST) {
        if (ply->wvalue_index == 0) {
            type = property->length_type;
            ply->wlength = (long) value;
        } else type = property->value_type;
    } else {
        type = property->type;
        ply->wlength = 0;
    }
    if (!ply->odriver->ohandler[type](ply, value)) {
        ply_error(ply, "Failed writing %s of %s %d (%s: %s)", 
                    property->name, element->name, 
                    ply->winstance_index, 
                    ply->odriver->name, ply_type_list[type]);
        return 0;
    }
    ply->wvalue_index++;
    if (ply->wvalue_index > ply->wlength) {
        ply->wvalue_index = 0;
        ply->wproperty++;
    }
    if (ply->wproperty >= element->nproperties) {
        ply->wproperty = 0;
        ply->winstance_index++;
        if (ply->storage_mode == PLY_ASCII) breakafter = 1;
    }
    if (ply->winstance_index >= element->ninstances) {
        ply->winstance_index = 0;
        ply->welement++;
    }
    return !breakafter || putc('\n', ply->fp) > 0;
}

int ply_close(p_ply ply) {
    long i;
    assert(ply && ply->fp);
    assert(ply->element || ply->nelements == 0);
    assert(!ply->element || ply->nelements > 0);
    /* write last chunk to file */
    if (ply->io_mode == PLY_WRITE && 
      fwrite(ply->buffer, 1, ply->buffer_last, ply->fp) < ply->buffer_last) {
        ply_error(ply, "Error closing up");
        return 0;
    }
    fclose(ply->fp);
    /* free all memory used by handle */
    if (ply->element) {
        for (i = 0; i < ply->nelements; i++) {
            p_ply_element element = &ply->element[i];
            if (element->property) free(element->property);
        }
        free(ply->element);
    }
    if (ply->obj_info) free(ply->obj_info);
    if (ply->comment) free(ply->comment);
    free(ply);
    return 1;
}

/* ----------------------------------------------------------------------
 * Query support functions
 * ---------------------------------------------------------------------- */
p_ply_element ply_get_next_element(p_ply ply, 
        p_ply_element last) {
    assert(ply);
    if (!last) return ply->element;
    last++;
    if (last < ply->element + ply->nelements) return last;
    else return NULL;
}

int ply_get_element_info(p_ply_element element, const char** name,
        long *ninstances) {
    assert(element);
    if (name) *name = element->name;
    if (ninstances) *ninstances = (long) element->ninstances;
    return 1;
}

p_ply_property ply_get_next_property(p_ply_element element, 
        p_ply_property last) {
    assert(element);
    if (!last) return element->property;
    last++;
    if (last < element->property + element->nproperties) return last;
    else return NULL;
}

int ply_get_property_info(p_ply_property property, const char** name,
        e_ply_type *type, e_ply_type *length_type, e_ply_type *value_type) {
    assert(property);
    if (name) *name = property->name;
    if (type) *type = property->type;
    if (length_type) *length_type = property->length_type;
    if (value_type) *value_type = property->value_type;
    return 1;

}

const char *ply_get_next_comment(p_ply ply, const char *last) {
    assert(ply);
    if (!last) return ply->comment; 
    last += LINESIZE;
    if (last < ply->comment + LINESIZE*ply->ncomments) return last;
    else return NULL;
}

const char *ply_get_next_obj_info(p_ply ply, const char *last) {
    assert(ply);
    if (!last) return ply->obj_info; 
    last += LINESIZE;
    if (last < ply->obj_info + LINESIZE*ply->nobj_infos) return last;
    else return NULL;
}

/* ----------------------------------------------------------------------
 * Callback argument support functions 
 * ---------------------------------------------------------------------- */
int ply_get_argument_element(p_ply_argument argument, 
        p_ply_element *element, long *instance_index) {
    assert(argument);
    if (!argument) return 0;
    if (element) *element = argument->element;
    if (instance_index) *instance_index = argument->instance_index;
    return 1;
}

int ply_get_argument_property(p_ply_argument argument, 
        p_ply_property *property, long *length, long *value_index) {
    assert(argument);
    if (!argument) return 0;
    if (property) *property = argument->property;
    if (length) *length = argument->length;
    if (value_index) *value_index = argument->value_index;
    return 1;
}

int ply_get_argument_user_data(p_ply_argument argument, void **pdata, 
        long *idata) {
    assert(argument);
    if (!argument) return 0;
    if (pdata) *pdata = argument->pdata;
    if (idata) *idata = argument->idata;
    return 1;
}

double ply_get_argument_value(p_ply_argument argument) {
    assert(argument);
    if (!argument) return 0.0;
    return argument->value;
}

/* ----------------------------------------------------------------------
 * Internal functions
 * ---------------------------------------------------------------------- */
static int ply_read_list_property(p_ply ply, p_ply_element element, 
        p_ply_property property, p_ply_argument argument) {
    int l;
    p_ply_read_cb read_cb = property->read_cb;
    p_ply_ihandler *driver = ply->idriver->ihandler; 
    /* get list length */
    p_ply_ihandler handler = driver[property->length_type];
    double length;
    if (!handler(ply, &length)) {
        ply_error(ply, "Error reading '%s' of '%s' number %d",
                property->name, element->name, argument->instance_index);
        return 0;
    }
    /* invoke callback to pass length in value field */
    argument->length = (long) length;
    argument->value_index = -1;
    argument->value = length;
    if (read_cb && !read_cb(argument)) {
        ply_error(ply, "Aborted by user");
        return 0;
    }
    /* read list values */
    handler = driver[property->value_type];
    /* for each value in list */
    for (l = 0; l < (long) length; l++) {
        /* read value from file */
        argument->value_index = l;
        if (!handler(ply, &argument->value)) {
            ply_error(ply, "Error reading value number %d of '%s' of "
                    "'%s' number %d", l+1, property->name, 
                    element->name, argument->instance_index);
            return 0;
        }
        /* invoke callback to pass value */
        if (read_cb && !read_cb(argument)) {
            ply_error(ply, "Aborted by user");
            return 0;
        }
    }
    return 1;
}