convert scale.c to scale.im so we have 8 bit/sample and double/sample
[imager.git] / imtoc.perl
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1#!perl -w
2use strict;
3
4my $src = shift;
5my $dest = shift
6 or usage();
7
8open SRC, "< $src"
9 or die "Cannot open $src: $!\n";
10
11my $cond;
12my $cond_line;
13my $save_code;
14my @code;
15my $code_line;
16my @out;
17my $failed;
18
19push @out, "#line 1 \"$src\"\n";
20while (defined(my $line = <SRC>)) {
a10945af 21 if ($line =~ /^\#code\s+(\S.+)$/) {
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22 $save_code
23 and do { warn "$src:$code_line:Unclosed #code block\n"; ++$failed; };
24
25 $cond = $1;
26 $cond_line = $.;
27 $code_line = $. + 1;
28 $save_code = 1;
29 }
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30 elsif ($line =~ /^\#code\s*$/) {
31 $save_code
32 and do { warn "$src:$code_line:Unclosed #code block\n"; ++$failed; };
33
34 $cond = '';
35 $cond_line = 0;
36 $code_line = $. + 1;
37 $save_code = 1;
38 }
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39 elsif ($line =~ /^\#\/code$/) {
40 $save_code
41 or do { warn "$src:$.:#/code without #code\n"; ++$failed; next; };
42
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43 if ($cond) {
44 push @out, "#line $cond_line \"$src\"\n";
45 push @out, " if ($cond) {\n";
46 }
47 push @out, "#undef IM_EIGHT_BIT\n",
48 "#define IM_EIGHT_BIT 1\n";
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49 push @out, "#line $code_line \"$src\"\n";
50 push @out, byte_samples(@code);
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51 push @out, " }\n", " else {\n"
52 if $cond;
53 push @out, "#undef IM_EIGHT_BIT\n";
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54 push @out, "#line $code_line \"$src\"\n";
55 push @out, double_samples(@code);
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56 push @out, " }\n"
57 if $cond;
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58 push @out, "#line $. \"$src\"\n";
59 @code = ();
60 $save_code = 0;
61 }
62 elsif ($save_code) {
63 push @code, $line;
64 }
65 else {
66 push @out, $line;
67 }
68}
69
70if ($save_code) {
71 warn "$src:$code_line:#code block not closed by EOF\n";
72 ++$failed;
73}
74
75close SRC;
76
77$failed
78 and die "Errors during parsing, aborting\n";
79
80open DEST, "> $dest"
81 or die "Cannot open $dest: $!\n";
82print DEST @out;
83close DEST;
84
85sub byte_samples {
86 # important we make a copy
87 my @lines = @_;
88
89 for (@lines) {
90 s/\bIM_GPIX\b/i_gpix/g;
91 s/\bIM_GLIN\b/i_glin/g;
92 s/\bIM_PPIX\b/i_ppix/g;
93 s/\bIM_PLIN\b/i_plin/g;
94 s/\bIM_GSAMP\b/i_gsamp/g;
95 s/\bIM_SAMPLE_MAX\b/255/g;
96 s/\bIM_SAMPLE_T/i_sample_t/g;
97 s/\bIM_COLOR\b/i_color/g;
98 s/\bIM_WORK_T\b/int/g;
99 s/\bIM_Sf\b/"%d"/g;
100 s/\bIM_Wf\b/"%d"/g;
a10945af 101 s/\bIM_SUFFIX\((\w+)\)/$1_8/g;
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102 }
103
104 @lines;
105}
106
107sub double_samples {
108 # important we make a copy
109 my @lines = @_;
110
111 for (@lines) {
112 s/\bIM_GPIX\b/i_gpixf/g;
113 s/\bIM_GLIN\b/i_glinf/g;
114 s/\bIM_PPIX\b/i_ppixf/g;
115 s/\bIM_PLIN\b/i_plinf/g;
116 s/\bIM_GSAMP\b/i_gsampf/g;
117 s/\bIM_SAMPLE_MAX\b/1.0/g;
118 s/\bIM_SAMPLE_T/i_fsample_t/g;
119 s/\bIM_COLOR\b/i_fcolor/g;
120 s/\bIM_WORK_T\b/double/g;
121 s/\bIM_Sf\b/"%f"/g;
122 s/\bIM_Wf\b/"%f"/g;
a10945af 123 s/\bIM_SUFFIX\((\w+)\)/$1_double/g;
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124 }
125
126 @lines;
127}
128
129=head1 NAME
130
131imtoc.perl - simple preprocessor for handling multiple sample sizes
132
133=head1 SYNOPSIS
134
135 /* in the source: */
136 #code condition true to work with 8-bit samples
137 ... code using preprocessor types/values ...
138 #/code
139
140 perl imtoc.perl foo.im foo.c
141
142=head1 DESCRIPTION
143
144This is a simple preprocessor that aims to reduce duplication of
145source code when implementing an algorithm both for 8-bit samples and
146double samples in Imager.
147
148Imager's Makefile.PL currently scans the MANIFEST for .im files and
149adds Makefile files to convert these to .c files.
150
151The beginning of a sample-independent section of code is preceded by:
152
153 #code expression
154
155where I<expression> should return true if processing should be done at
1568-bits/sample.
157
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158You can also use a #code block around a function definition to produce
1598-bit and double sample versions of a function. In this case #code
160has no expression and you will need to use IM_SUFFIX() to produce
161different function names.
162
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163The end of a sample-independent section of code is terminated by:
164
165 #/code
166
167#code sections cannot be nested.
168
169#/code without a starting #code is an error.
170
171The following types and values are defined in a #code section:
172
173=over
174
175=item *
176
177IM_GPIX(im, x, y, &col)
178
179=item *
180
181IM_GLIN(im, l, r, y, colors)
182
183=item *
184
185IM_PPIX(im, x, y, &col)
186
187=item *
188
189IM_PLIN(im, x, y, colors)
190
191=item *
192
193IM_GSAMP(im, l, r, y, samples, chans, chan_count)
194
195These correspond to the appropriate image function, eg. IM_GPIX()
196becomes i_gpix() or i_gpixf() as appropriate.
197
198=item *
199
200IM_SAMPLE_MAX - maximum value for a sample
201
202=item *
203
204IM_SAMPLE_T - type of a sample (i_sample_t or i_fsample_t)
205
206=item *
207
208IM_COLOR - color type, either i_color or i_fcolor.
209
210=item *
211
212IM_WORK_T - working sample type, either int or double.
213
214=item *
215
216IM_Sf - format string for the sample type, C<"%d"> or C<"%f">.
217
218=item *
219
220IM_Wf - format string for the work type, C<"%d"> or C<"%f">.
221
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222=item *
223
224IM_SUFFIX(identifier) - adds _8 or _double onto the end of identifier.
225
226=item *
227
228IM_EIGHT_BIT - this is a macro defined only in 8-bit/sample code.
229
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230=back
231
232Other types, functions and values may be added in the future.
233
234=head1 AUTHOR
235
236Tony Cook <tony@imager.perl.org>
237
238=cut