From cc3b67814bd3d1d26e1d1d5523db7bf19384bf33 Mon Sep 17 00:00:00 2001
From: Javier Sancho <jsf@jsancho.org>
Date: Fri, 11 Jul 2014 10:18:18 +0200
Subject: [PATCH] Rewrite definitions with new conversion-types

* src/assimp.scm: Remove type generation functions and use 'field'
  syntax in every request to data from C parser.

* src/low-level.scm: Add type generation functions using new 'field'
  syntax.
---
 src/assimp.scm    | 247 +++++-----------------------------------------
 src/low-level.scm | 124 ++++++++++++++++++++++-
 2 files changed, 148 insertions(+), 223 deletions(-)

diff --git a/src/assimp.scm b/src/assimp.scm
index 03c9b33..9f6bfc2 100644
--- a/src/assimp.scm
+++ b/src/assimp.scm
@@ -16,11 +16,10 @@
 
 
 (define-module (assimp assimp)
+  #:use-module (assimp low-level)
   #:use-module (assimp low-level material)
   #:use-module (assimp low-level mesh)
   #:use-module (assimp low-level scene)
-  #:use-module (ice-9 iconv)
-  #:use-module (rnrs bytevectors)
   #:use-module (system foreign))
 
 (define libassimp (dynamic-link "libassimp"))
@@ -31,216 +30,21 @@
 		      (list '* unsigned-int)))
 
 
-;;; Type Generation
-
-(define-syntax define-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 ()
-      ((_ name parser (field 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")))
-         #'(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-contents wrapped)
-	       (let ((unwrapped (unwrap-type wrapped)))
-		 (cond ((= (pointer-address unwrapped) 0)
-			'())
-		       (else
-			(filter
-			 (lambda (f)
-			   (not (null? (cdr f))))
-			 (list (cons 'field (field-proc unwrapped))
-			       ...))))))))))))
-
-(define (bv-uint-ref pointer index)
-  (bytevector-uint-ref
-   (pointer->bytevector pointer 4 index)
-   0
-   (native-endianness)
-   4))
-
-(define (get-aiString index)
-  (lambda (pointer)
-    (let* ((length (bv-uint-ref pointer index))
-	   (data (pointer->bytevector pointer length (+ index 4))))
-      (bytevector->string data (fluid-ref %default-port-encoding)))))
-
-(define* (get-pointer index #:optional wrap-proc)
-  (lambda (pointer)
-    (let ((p (bv-uint-ref pointer index)))
-      (cond ((= p 0) '())
-	    (else
-	     (let ((p2 (make-pointer p)))
-	       (list
-		(cond (wrap-proc (wrap-proc p2))
-		      (else p2)))))))))
-
-(define (get-array num-index root-index type)
-  (lambda (pointer)
-    (let ((num (bv-uint-ref pointer num-index))
-	  (rootp (make-pointer (bv-uint-ref pointer root-index))))
-      (cond ((> num 0)
-	     (array->list
-	      (pointer->bytevector rootp num 0 type)))
-	    (else
-	     '())))))
-
-(define* (get-structs-array num-index root-index struct-size #:optional wrap-proc)
-  (lambda (pointer)
-    (let ((num (bv-uint-ref pointer num-index))
-	  (rootp (bv-uint-ref pointer root-index)))
-      (let loop ((i (- num 1)))
-	(cond ((< i 0)
-	       '())
-	      (else
-	       (let* ((p (make-pointer (+ rootp (* i struct-size))))
-		      (wp (if wrap-proc (wrap-proc p) p)))
-		 (cons wp (loop (- i 1))))))))))
-
-(define* (get-pointer-of-pointers num-index root-index #:optional wrap-proc)
-  (lambda (pointer)
-    (let* ((num (bv-uint-ref pointer num-index))
-	   (rootp (make-pointer (bv-uint-ref pointer root-index))))
-      (let loop ((i 0))
-	(cond ((= i num)
-	       '())
-	      (else
-	       (let* ((p (make-pointer (bv-uint-ref rootp (* 4 i))))
-		      (wp (if wrap-proc (wrap-proc p) p)))
-		 (cons wp (loop (+ i 1))))))))))
-
-(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 wrapped)
-	       (let ((alist (type-parse wrapped)))
-		 (list (cons 'field-name (field-proc alist))
-		       ...)))
-	     (define (field-reader wrapped)
-	       (let ((alist (type-parse wrapped)))
-		 (field-proc alist)))
-	     ...))))))
-
-(define (field name)
-  (lambda (alist)
-    (assoc-ref alist name)))
-
-(define (get-element-address root-pointer offset)
-  (make-pointer (+ (pointer-address root-pointer) offset)))
-
-(define* (array size-tag root-tag #:key (element-size 4) (element-proc bv-uint-ref))
-  (lambda (alist)
-    (let ((size (assoc-ref alist size-tag))
-	  (root (assoc-ref alist root-tag)))
-      (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 (wrap proc 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))))
-  (lambda (alist)
-    (let ((res (proc alist)))
-      (cond ((list? res)
-	     (map make-wrap res))
-	    (else
-	     (make-wrap res))))))
-
-(define (sized-string string-tag)
-  (lambda (alist)
-    (let ((s (assoc-ref alist string-tag)))
-      (cond (s
-	     (bytevector->string
-	      (u8-list->bytevector (list-head (cadr s) (car s)))
-	      (fluid-ref %default-port-encoding)))
-	    (else
-	     #f)))))
-
-
 ;;; Scenes
 
 (define-conversion-type parse-aiScene -> scene
   (flags (field 'mFlags))
   (root-node (wrap (field 'mRootNode) wrap-node))
-  (meshes (wrap (array 'mNumMeshes 'mMeshes) wrap-mesh))
-  (materials (wrap (array 'mNumMaterials 'mMaterials) wrap-material))
-  (animations (array 'mNumAnimations 'mAnimations))
-  (textures (array 'mNumTextures 'mTextures))
-  (lights (array 'mNumLights 'mLights))
-  (cameras (array 'mNumCameras 'mCameras)))
-
- (define (load-scene filename flags)
-   (wrap-scene
-    (aiImportFile (string->pointer filename)
+  (meshes (wrap (array (field 'mNumMeshes) (field 'mMeshes)) wrap-mesh))
+  (materials (wrap (array (field 'mNumMaterials) (field 'mMaterials)) wrap-material))
+  (animations (array (field 'mNumAnimations) (field 'mAnimations)))
+  (textures (array (field 'mNumTextures) (field 'mTextures)))
+  (lights (array (field 'mNumLights) (field 'mLights)))
+  (cameras (array (field 'mNumCameras) (field 'mCameras))))
+
+(define (load-scene filename flags)
+  (wrap-scene
+   (aiImportFile (string->pointer filename)
  		 flags)))
 
 (export load-scene
@@ -259,14 +63,14 @@
 ;;; Nodes
 
 (define-conversion-type parse-aiNode -> node
-  (name (sized-string 'mName))
+  (name (sized-string (field 'mName)))
   (transformation (field 'mTransformation))
   (parent (wrap (field 'mParent) wrap-node))
-  (children (wrap (array 'mNumChildren 'mChildren) wrap-node))
-  (meshes (array 'mNumMeshes 'mMeshes)))
+  (children (wrap (array (field 'mNumChildren) (field 'mChildren)) wrap-node))
+  (meshes (array (field 'mNumMeshes) (field 'mMeshes))))
 
 (export node?
- 	node-contents
+	node-contents
 	node-name
 	node-transformation
 	node-parent
@@ -277,19 +81,18 @@
 ;;; Meshes
 
 (define-conversion-type parse-aiMesh -> mesh
-  (name (sized-string 'mName))
+  (name (sized-string (field 'mName)))
   (primitive-types (field 'mPrimitiveTypes))
-  (vertices (array 'mNumVertices 'mVertices #:element-proc get-element-address))
-  (faces (wrap (array 'mNumFaces 'mFaces #:element-size 8 #:element-proc get-element-address) wrap-face))
-  (normals (array 'mNumVertices 'mNormals #:element-size 12 #:element-proc get-element-address))
-  (tangents (array 'mNumVertices 'mTangents #:element-size 12 #:element-proc get-element-address))
-  (bitangents (array 'mNumVertices 'mBitangents #:element-size 12 #:element-proc get-element-address))
+  (vertices (array (field 'mNumVertices) (field 'mVertices) #:element-proc get-element-address))
+  (faces (wrap (array (field 'mNumFaces) (field 'mFaces) #:element-size 8 #:element-proc get-element-address) wrap-face))
+  (normals (array (field 'mNumVertices) (field 'mNormals) #:element-size 12 #:element-proc get-element-address))
+  (tangents (array (field 'mNumVertices) (field 'mTangents) #:element-size 12 #:element-proc get-element-address))
+  (bitangents (array (field 'mNumVertices) (field 'mBitangents) #:element-size 12 #:element-proc get-element-address))
   (colors (field 'mColors))
   (texture-coords (field 'mTextureCoords))
   (num-uv-components (field 'mNumUVComponents))
-  (bones (array 'mNumBones 'mBones))
-  (material-index (field 'mMaterialIndex))
-)
+  (bones (array (field 'mNumBones) (field 'mBones)))
+  (material-index (field 'mMaterialIndex)))
 
 (export mesh?
 	mesh-contents
@@ -310,7 +113,7 @@
 ;;; Materials
 
 (define-conversion-type parse-aiMaterial -> material
-  (properties (array 'mNumProperties 'mProperties))
+  (properties (array (field 'mNumProperties) (field 'mProperties)))
   (num-allocated (field 'mNumAllocated)))
 
 (export material?
@@ -322,7 +125,7 @@
 ;;; Faces
 
 (define-conversion-type parse-aiFace -> face
-  (indices (array 'mNumIndices 'mIndices)))
+  (indices (array (field 'mNumIndices) (field 'mIndices))))
 
 (export face?
 	face-contents
diff --git a/src/low-level.scm b/src/low-level.scm
index a184082..53bb39e 100644
--- a/src/low-level.scm
+++ b/src/low-level.scm
@@ -16,9 +16,13 @@
 
 
 (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 ()
@@ -30,4 +34,122 @@
 		  '(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)
-- 
2.39.5