summaryrefslogtreecommitdiff
path: root/source/fitz/test-device.c
blob: d0bd08c729976f0c0234af3deeb52fa076a662fa (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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
#include <mupdf/fitz.h>

typedef struct fz_test_device_s
{
	fz_device super;
	int *is_color;
	float threshold;
} fz_test_device;

static int
is_rgb_color(float threshold, float r, float g, float b)
{
	float rg_diff = fz_abs(r - g);
	float rb_diff = fz_abs(r - b);
	float gb_diff = fz_abs(g - b);
	return rg_diff > threshold || rb_diff > threshold || gb_diff > threshold;
}

static int
is_rgb_color_u8(int threshold_u8, int r, int g, int b)
{
	int rg_diff = fz_absi(r - g);
	int rb_diff = fz_absi(r - b);
	int gb_diff = fz_absi(g - b);
	return rg_diff > threshold_u8 || rb_diff > threshold_u8 || gb_diff > threshold_u8;
}

static void
fz_test_color(fz_context *ctx, fz_device *dev, fz_colorspace *colorspace, const float *color)
{
	fz_test_device *t = (fz_test_device*)dev;

	if (!*t->is_color && colorspace && colorspace != fz_device_gray(ctx))
	{
		if (colorspace == fz_device_rgb(ctx))
		{
			if (is_rgb_color(t->threshold, color[0], color[1], color[2]))
			{
				*t->is_color = 1;
				dev->hints |= FZ_IGNORE_IMAGE;
				fz_throw(ctx, FZ_ERROR_ABORT, "Page found as color; stopping interpretation");
			}
		}
		else
		{
			float rgb[3];
			fz_convert_color(ctx, fz_device_rgb(ctx), rgb, colorspace, color);
			if (is_rgb_color(t->threshold, rgb[0], rgb[1], rgb[2]))
			{
				*t->is_color = 1;
				dev->hints |= FZ_IGNORE_IMAGE;
				fz_throw(ctx, FZ_ERROR_ABORT, "Page found as color; stopping interpretation");
			}
		}
	}
}

static void
fz_test_fill_path(fz_context *ctx, fz_device *dev, fz_path *path, int even_odd, const fz_matrix *ctm,
	fz_colorspace *colorspace, float *color, float alpha)
{
	if (alpha != 0.0f)
		fz_test_color(ctx, dev, colorspace, color);
}

static void
fz_test_stroke_path(fz_context *ctx, fz_device *dev, fz_path *path, fz_stroke_state *stroke,
	const fz_matrix *ctm, fz_colorspace *colorspace, float *color, float alpha)
{
	if (alpha != 0.0f)
		fz_test_color(ctx, dev, colorspace, color);
}

static void
fz_test_fill_text(fz_context *ctx, fz_device *dev, fz_text *text, const fz_matrix *ctm,
	fz_colorspace *colorspace, float *color, float alpha)
{
	if (alpha != 0.0f)
		fz_test_color(ctx, dev, colorspace, color);
}

static void
fz_test_stroke_text(fz_context *ctx, fz_device *dev, fz_text *text, fz_stroke_state *stroke,
	const fz_matrix *ctm, fz_colorspace *colorspace, float *color, float alpha)
{
	if (alpha != 0.0f)
		fz_test_color(ctx, dev, colorspace, color);
}

struct shadearg
{
	fz_device *dev;
	fz_shade *shade;
};

static void
prepare_vertex(fz_context *ctx, void *arg_, fz_vertex *v, const float *color)
{
	struct shadearg *arg = arg_;
	fz_device *dev = arg->dev;
	fz_shade *shade = arg->shade;
	if (!shade->use_function)
		fz_test_color(ctx, dev, shade->colorspace, color);
}

static void
fz_test_fill_shade(fz_context *ctx, fz_device *dev, fz_shade *shade, const fz_matrix *ctm, float alpha)
{
	if (shade->use_function)
	{
		int i;
		for (i = 0; i < 256; i++)
			fz_test_color(ctx, dev, shade->colorspace, shade->function[i]);
	}
	else
	{
		struct shadearg arg;
		arg.dev = dev;
		arg.shade = shade;
		fz_process_mesh(ctx, shade, ctm, prepare_vertex, NULL, &arg);
	}
}

static void
fz_test_fill_image(fz_context *ctx, fz_device *dev, fz_image *image, const fz_matrix *ctm, float alpha)
{
	fz_test_device *t = (fz_test_device*)dev;

	fz_pixmap *pix;
	unsigned int count, i, k;
	unsigned char *s;

	if (*t->is_color || !image->colorspace || image->colorspace == fz_device_gray(ctx))
		return;

	if (image->buffer && image->bpc == 8)
	{
		fz_stream *stream = fz_open_compressed_buffer(ctx, image->buffer);
		count = (unsigned int)image->w * (unsigned int)image->h;
		if (image->colorspace == fz_device_rgb(ctx))
		{
			int threshold_u8 = t->threshold * 255;
			for (i = 0; i < count; i++)
			{
				int r = fz_read_byte(ctx, stream);
				int g = fz_read_byte(ctx, stream);
				int b = fz_read_byte(ctx, stream);
				if (is_rgb_color_u8(threshold_u8, r, g, b))
				{
					*t->is_color = 1;
					dev->hints |= FZ_IGNORE_IMAGE;
					fz_drop_stream(ctx, stream);
					fz_throw(ctx, FZ_ERROR_ABORT, "Page found as color; stopping interpretation");
					break;
				}
			}
		}
		else
		{
			fz_color_converter cc;
			unsigned int n = (unsigned int)image->n;

			fz_init_cached_color_converter(ctx, &cc, fz_device_rgb(ctx), image->colorspace);
			for (i = 0; i < count; i++)
			{
				float cs[FZ_MAX_COLORS];
				float ds[FZ_MAX_COLORS];

				for (k = 0; k < n; k++)
					cs[k] = fz_read_byte(ctx, stream) / 255.0f;

				cc.convert(ctx, &cc, ds, cs);

				if (is_rgb_color(t->threshold, ds[0], ds[1], ds[2]))
				{
					*t->is_color = 1;
					dev->hints |= FZ_IGNORE_IMAGE;
					break;
				}
			}
			fz_fin_cached_color_converter(ctx, &cc);
		}
		fz_drop_stream(ctx, stream);
		return;
	}

	pix = fz_new_pixmap_from_image(ctx, image, 0, 0);
	if (pix == NULL) /* Should never happen really, but... */
		return;

	count = (unsigned int)pix->w * (unsigned int)pix->h;
	s = pix->samples;

	if (pix->colorspace == fz_device_rgb(ctx))
	{
		int threshold_u8 = t->threshold * 255;
		for (i = 0; i < count; i++)
		{
			if (s[3] != 0 && is_rgb_color_u8(threshold_u8, s[0], s[1], s[2]))
			{
				*t->is_color = 1;
				dev->hints |= FZ_IGNORE_IMAGE;
				fz_drop_pixmap(ctx, pix);
				fz_throw(ctx, FZ_ERROR_ABORT, "Page found as color; stopping interpretation");
				break;
			}
			s += 4;
		}
	}
	else
	{
		fz_color_converter cc;
		unsigned int n = (unsigned int)pix->n-1;

		fz_init_cached_color_converter(ctx, &cc, fz_device_rgb(ctx), pix->colorspace);
		for (i = 0; i < count; i++)
		{
			float cs[FZ_MAX_COLORS];
			float ds[FZ_MAX_COLORS];

			for (k = 0; k < n; k++)
				cs[k] = (*s++) / 255.0f;
			if (*s++ == 0)
				continue;

			cc.convert(ctx, &cc, ds, cs);

			if (is_rgb_color(t->threshold, ds[0], ds[1], ds[2]))
			{
				*t->is_color = 1;
				dev->hints |= FZ_IGNORE_IMAGE;
				fz_drop_pixmap(ctx, pix);
				fz_throw(ctx, FZ_ERROR_ABORT, "Page found as color; stopping interpretation");
				break;
			}
		}
		fz_fin_cached_color_converter(ctx, &cc);
	}

	fz_drop_pixmap(ctx, pix);
}

static void
fz_test_fill_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const fz_matrix *ctm,
	fz_colorspace *colorspace, float *color, float alpha)
{
	/* We assume that at least some of the image pixels are non-zero */
	fz_test_color(ctx, dev, colorspace, color);
}

fz_device *
fz_new_test_device(fz_context *ctx, int *is_color, float threshold)
{
	fz_test_device *dev = fz_new_device(ctx, sizeof *dev);

	dev->super.fill_path = fz_test_fill_path;
	dev->super.stroke_path = fz_test_stroke_path;
	dev->super.fill_text = fz_test_fill_text;
	dev->super.stroke_text = fz_test_stroke_text;
	dev->super.fill_shade = fz_test_fill_shade;
	dev->super.fill_image = fz_test_fill_image;
	dev->super.fill_image_mask = fz_test_fill_image_mask;

	dev->is_color = is_color;
	dev->threshold = threshold;

	*dev->is_color = 0;

	return (fz_device*)dev;
}