(define-module (assimp low-level)
+ #:use-module (ice-9 iconv)
+ #:use-module (rnrs bytevectors)
#:use-module (system foreign))
+;;; Parsers Definition
+
(define-syntax define-struct-parser
(lambda (x)
(syntax-case x ()
'(field-name ...)
(parse-c-struct pointer (list field-type ...)))))))))
-(export define-struct-parser)
+(export-syntax define-struct-parser)
+
+
+;;; Type Generation
+
+(define-syntax define-conversion-type
+ (lambda (x)
+ (define (mk-string . args)
+ (string-concatenate
+ (map (lambda (a)
+ (if (string? a)
+ a
+ (symbol->string (syntax->datum a))))
+ args)))
+ (define (mk-symbol . args)
+ (datum->syntax x
+ (string->symbol
+ (apply mk-string args))))
+ (syntax-case x (->)
+ ((_ parser -> name (field-name field-proc) ...)
+ (with-syntax ((type? (mk-symbol #'name "?"))
+ (wrap-type (mk-symbol "wrap-" #'name))
+ (unwrap-type (mk-symbol "unwrap-" #'name))
+ (output-string (mk-string "#<" #'name " ~x>"))
+ (type-contents (mk-symbol #'name "-contents"))
+ (type-parse (mk-symbol #'name "-parse"))
+ ((field-reader ...) (map (lambda (f) (mk-symbol #'name "-" (car f))) #'((field-name field-proc) ...))))
+ #'(begin
+ (define-wrapped-pointer-type name
+ type?
+ wrap-type unwrap-type
+ (lambda (x p)
+ (format p output-string
+ (pointer-address (unwrap-type x)))))
+ (define (type-parse wrapped)
+ (let ((unwrapped (unwrap-type wrapped)))
+ (cond ((= (pointer-address unwrapped) 0)
+ '())
+ (else
+ (parser unwrapped)))))
+ (define-type-contents type-contents type-parse (field-name field-proc) ...)
+ (define-field-reader field-reader type-parse field-proc)
+ ...
+ ))))))
+
+(define-macro (define-type-contents type-contents type-parse . fields)
+ `(define (,type-contents wrapped)
+ (let ((alist (,type-parse wrapped)))
+ (list ,@(map (lambda (f)
+ `(cons ',(car f) ,(cadr f)))
+ fields)))))
+
+(define-macro (define-field-reader field-reader type-parse body)
+ `(define (,field-reader wrapped)
+ (let ((alist (,type-parse wrapped)))
+ ,body)))
+
+(define-macro (field name)
+ `(assoc-ref alist ,name))
+
+(export-syntax define-conversion-type
+ field)
+
+
+;;; Support functions for type generation
+
+(define (bv-uint-ref pointer index)
+ (bytevector-uint-ref
+ (pointer->bytevector pointer 4 index)
+ 0
+ (native-endianness)
+ 4))
+
+(define* (array size root #:key (element-size 4) (element-proc bv-uint-ref))
+ (cond ((= (pointer-address root) 0)
+ '())
+ (else
+ (let loop ((i 0))
+ (cond ((= i size)
+ '())
+ (else
+ (cons (element-proc root (* element-size i))
+ (loop (+ i 1)))))))))
+
+(define (get-element-address root-pointer offset)
+ (make-pointer (+ (pointer-address root-pointer) offset)))
+
+(define (sized-string s)
+ (cond (s
+ (bytevector->string
+ (u8-list->bytevector (list-head (cadr s) (car s)))
+ (fluid-ref %default-port-encoding)))
+ (else
+ #f)))
+
+(define (wrap pointers wrap-proc)
+ (define (make-wrap element)
+ (let ((pointer
+ (cond ((pointer? element)
+ (if (= (pointer-address element) 0)
+ #f
+ element))
+ ((= element 0)
+ #f)
+ (else
+ (make-pointer element)))))
+ (cond (pointer
+ (wrap-proc pointer))
+ (else
+ #f))))
+ (cond ((list? pointers)
+ (map make-wrap pointers))
+ (else
+ (make-wrap pointers))))
+
+(export array
+ get-element-address
+ sized-string
+ wrap)