blob: 4ba60fefdda9afccd304a2268259a0c06248e17d (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
;;; Chickadee Game Toolkit
;;; Copyright © 2021 David Thompson <dthompson2@worcester.edu>
;;;
;;; Chickadee is free software: you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License as published
;;; by the Free Software Foundation, either version 3 of the License,
;;; or (at your option) any later version.
;;;
;;; Chickadee is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;;; General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with this program. If not, see
;;; <http://www.gnu.org/licenses/>.
;;; Commentary:
;;
;; JPEG image loading.
;;
;;; Code:
(define-module (chickadee image jpeg)
#:use-module (chickadee config)
#:use-module (ice-9 binary-ports)
#:use-module (ice-9 exceptions)
#:use-module (ice-9 format)
#:use-module (ice-9 match)
#:use-module (rnrs bytevectors)
#:use-module (srfi srfi-9)
#:use-module (srfi srfi-11)
#:use-module (system foreign)
#:export (load-jpeg))
;;;
;;; Enums
;;;
(define TJERR_WARNING 0)
(define TJERR_FATAL 1)
(define TJPF_RGBA 7)
(define TJFLAG_BOTTOMUP 2)
;;;
;;; Low-level bindings
;;;
(define libturbojpeg-func
(let ((lib (dynamic-link* %libturbojpeg)))
(lambda (return-type function-name arg-types)
(pointer->procedure return-type
(dynamic-func function-name lib)
arg-types))))
(define-syntax-rule (define-foreign name return-type func-name arg-types)
(define name
(libturbojpeg-func return-type func-name arg-types)))
(define-foreign tj-get-error-code
int "tjGetErrorCode" '(*))
(define-foreign tj-get-error-str2
'* "tjGetErrorStr2" '(*))
(define-foreign tj-init-decompress
'* "tjInitDecompress" '())
(define-foreign tj-destroy
int "tjDestroy" '(*))
(define-foreign tj-decompress-header3
int "tjDecompressHeader3" (list '* '* unsigned-long '* '* '* '*))
(define-foreign tj-decompress2
int "tjDecompress2" (list '* '* unsigned-long '* int int int int int))
;;;
;;; High-level bindings
;;;
(define (display-tjhandle handle port)
(display "#<tjhandle>" port))
(define-wrapped-pointer-type <tjhandle> tjhandle?
wrap-tjhandle unwrap-tjhandle display-tjhandle)
(define (check-error handle)
(let* ((ptr (if handle (unwrap-tjhandle handle) %null-pointer))
(error-code (tj-get-error-code ptr))
(error-string (pointer->string (tj-get-error-str2 ptr))))
(if (= error-code TJERR_FATAL)
(raise-exception (make-exception-with-message error-string))
(format (current-error-port) "warning: ~a~%" error-string))))
(define (init-decompress)
(wrap-tjhandle (tj-init-decompress)))
(define (destroy-handle handle)
(tj-destroy (unwrap-tjhandle handle)))
(define (decompress-headers handle buffer)
(let ((result (make-s32vector 4)))
(unless (zero? (tj-decompress-header3 (unwrap-tjhandle handle)
(bytevector->pointer buffer)
(bytevector-length buffer)
(bytevector->pointer result)
(bytevector->pointer result 4)
(bytevector->pointer result 8)
(bytevector->pointer result 12)))
(check-error handle))
(values (s32vector-ref result 0)
(s32vector-ref result 1)
(s32vector-ref result 2)
(s32vector-ref result 3))))
(define (decompress handle buffer width pitch height pixel-format flags)
(let ((bv (make-bytevector (* pitch height))))
(unless (zero? (tj-decompress2 (unwrap-tjhandle handle)
(bytevector->pointer buffer)
(bytevector-length buffer)
(bytevector->pointer bv)
width pitch height pixel-format flags))
(check-error handle))
bv))
(define (load-jpeg file-name)
(if (file-exists? file-name)
(let ((buffer (call-with-input-file file-name get-bytevector-all))
(handle (init-decompress)))
(dynamic-wind
(lambda () #t)
(lambda ()
(let-values (((width height subsamples color-space)
(decompress-headers handle buffer)))
(let ((pitch (* width 4)))
(values (decompress handle buffer width pitch height
TJPF_RGBA 0) ; TJFLAG_BOTTOMUP
width height))))
(lambda ()
(destroy-handle handle))))
(raise-exception
(make-exception (make-external-error)
(make-exception-with-message
(string-append "file not found: " file-name))))))
|
