X-Git-Url: https://git.jsancho.org/?a=blobdiff_plain;f=src%2Flow-level.scm;h=148b26d9b102e5e41b5824c9d095f3785921e54b;hb=d90f35ebd1816b818700badf108882040e82c5cb;hp=a184082929ae37f43c003f5e384141e6e5ee86c1;hpb=63cca7faa50c513c8aa201d15336e555438fddb5;p=guile-assimp.git

diff --git a/src/low-level.scm b/src/low-level.scm
index a184082..148b26d 100644
--- a/src/low-level.scm
+++ b/src/low-level.scm
@@ -16,18 +16,215 @@
 
 
 (define-module (assimp low-level)
+  #:use-module (ice-9 iconv)
+  #:use-module (rnrs bytevectors)
   #:use-module (system foreign))
 
 
+;;; Generic Functions
+
+(define (mk-string . args)
+  (string-concatenate
+   (map (lambda (a)
+	  (if (string? a)
+	      a
+	      (symbol->string (syntax->datum a))))
+	args)))
+
+(define (lambda-mk-symbol x)
+  (lambda args
+    (datum->syntax x
+      (string->symbol
+       (apply mk-string args)))))
+
+
+;;; Parsers Definition
+
 (define-syntax define-struct-parser
   (lambda (x)
     (syntax-case x ()
       ((_ name (field type) ...)
        (with-syntax (((field-name ...) (map car #'((field type) ...)))
 		     ((field-type ...) (map cadr #'((field type) ...))))
-         #'(define (name pointer)
-	     (map cons
-		  '(field-name ...)
-		  (parse-c-struct pointer (list field-type ...)))))))))
+         #'(define* (name pointer-or-data #:key (reverse #f))
+	     (cond (reverse
+		    (make-c-struct
+		     (list field-type ...)
+		     pointer-or-data))
+		   (else
+		    (map cons
+			 '(field-name ...)
+			 (parse-c-struct pointer-or-data (list field-type ...)))))))))))
+
+(export-syntax define-struct-parser)
+
+
+;;; Type Generation
+
+(define-syntax define-conversion-type
+  (lambda (x)
+    (define mk-symbol (lambda-mk-symbol x))
+    (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
+	 (reverse
+	  (let loop ((i 0) (res '()))
+	    (cond ((= i size)
+		   res)
+		  (else
+		   (loop (+ i 1) (cons (element-proc root (* element-size i)) res)))))))))
+
+(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)
+
+
+;;; Function Mappers
+
+(define-syntax define-foreign-function
+  (lambda (x)
+    (syntax-case x (->)
+      ((_ ((foreign-lib name) arg-type ...) -> return-type)
+       (with-syntax ((name-string (datum->syntax x (symbol->string (syntax->datum #'name)))))
+         #'(define name
+	     (pointer->procedure return-type
+				 (dynamic-func name-string foreign-lib)
+				 (list arg-type ...))))))))
+
+
+(define libassimp (dynamic-link "libassimp"))
+
+(define-syntax define-assimp-function
+  (syntax-rules (->)
+    ((_ (name arg-type ...) -> return-type)
+     (define-foreign-function ((libassimp name) arg-type ...) -> return-type))))
+
+
+(export-syntax define-foreign-function
+	       define-assimp-function)
+
+
+;;; Enumerators and bitfields (copìed from figl code, thanks to Andy Wingo
+
+(define-syntax-rule (define-enumeration enumerator (name value) ...)
+  (define-syntax enumerator
+    (lambda (x)
+      (syntax-case x ()
+        ((_)
+         #''(name ...))
+        ((_ enum) (number? (syntax->datum #'enum))
+         #'enum)
+        ((_ enum)
+         #'(or (assq-ref `((name . ,(syntax->datum value)) ...)
+			 (syntax->datum #'enum))
+	       (syntax-violation 'enumerator "invalid enumerated value"
+				 #'enum)))))))
+
+(define-syntax-rule (define-bitfield bitfield (name value) ...)
+  (define-syntax bitfield
+    (lambda (x)
+      (syntax-case x () 
+        ((_)
+         #''(name ...))
+        ((_ bit (... ...))
+         #`(logior
+            #,@(map
+                (lambda (bit)
+                  (let ((datum (syntax->datum bit)))
+                    (if (number? datum)
+                        datum
+                        (or (assq-ref '((name . value) ...) datum)
+                            (syntax-violation 'bitfield "invalid bitfield value"
+                                              bit)))))
+                #'(bit (... ...)))))))))
 
-(export define-struct-parser)
+(export-syntax define-enumeration
+	       define-bitfield)