vips.h

#include <stdlib.h>
#include <string.h>
#include <vips/vips.h>
#include <vips/foreign.h>
#include <vips/vips7compat.h>

/**
 * Starting libvips 7.41, VIPS_ANGLE_x has been renamed to VIPS_ANGLE_Dx
 * "to help python". So we provide the macro to correctly build for versions
 * before 7.41.x.
 * https://github.com/jcupitt/libvips/blob/master/ChangeLog#L128
 */

#if (VIPS_MAJOR_VERSION == 7 && VIPS_MINOR_VERSION < 41)
#define VIPS_ANGLE_D0 VIPS_ANGLE_0
#define VIPS_ANGLE_D90 VIPS_ANGLE_90
#define VIPS_ANGLE_D180 VIPS_ANGLE_180
#define VIPS_ANGLE_D270 VIPS_ANGLE_270
#endif

#define EXIF_IFD0_ORIENTATION "exif-ifd0-Orientation"

#define INT_TO_GBOOLEAN(bool) (bool > 0 ? TRUE : FALSE)


enum types {
	UNKNOWN = 0,
	JPEG,
	WEBP,
	PNG,
	TIFF,
	GIF,
	PDF,
	SVG,
	MAGICK
};

typedef struct {
	const char *Text;
	const char *Font;
} WatermarkTextOptions;

typedef struct {
	int    Width;
	int    DPI;
	int    Margin;
	int    NoReplicate;
	float  Opacity;
	double Background[3];
} WatermarkOptions;

typedef struct {
	int    Left;
	int    Top;
	float    Opacity;
} WatermarkImageOptions;

static unsigned long
has_profile_embed(VipsImage *image) {
	return vips_image_get_typeof(image, VIPS_META_ICC_NAME);
}

static void
remove_profile(VipsImage *image) {
	vips_image_remove(image, VIPS_META_ICC_NAME);
}

static int
has_alpha_channel(VipsImage *image) {
	return (
		(image->Bands == 2 && image->Type == VIPS_INTERPRETATION_B_W) ||
		(image->Bands == 4 && image->Type != VIPS_INTERPRETATION_CMYK) ||
		(image->Bands == 5 && image->Type == VIPS_INTERPRETATION_CMYK)
	) ? 1 : 0;
}

/**
 * This method is here to handle the weird initialization of the vips lib.
 * libvips use a macro VIPS_INIT() that call vips__init() in version < 7.41,
 * or calls vips_init() in version >= 7.41.
 *
 * Anyway, it's not possible to build bimg on Debian Jessie with libvips 7.40.x,
 * as vips_init() is a macro to VIPS_INIT(), which is also a macro, hence, cgo
 * is unable to determine the return type of vips_init(), making the build impossible.
 * In order to correctly build bimg, for version < 7.41, we should undef vips_init and
 * creates a vips_init() method that calls VIPS_INIT().
 */

#if (VIPS_MAJOR_VERSION == 7 && VIPS_MINOR_VERSION < 41)
#undef vips_init
int
vips_init(const char *argv0)
{
	return VIPS_INIT(argv0);
}
#endif

void
vips_enable_cache_set_trace() {
	vips_cache_set_trace(TRUE);
}

int
vips_affine_interpolator(VipsImage *in, VipsImage **out, double a, double b, double c, double d, VipsInterpolate *interpolator) {
	return vips_affine(in, out, a, b, c, d, "interpolate", interpolator, NULL);
}

int
vips_jpegload_buffer_shrink(void *buf, size_t len, VipsImage **out, int shrink) {
	return vips_jpegload_buffer(buf, len, out, "shrink", shrink, NULL);
}

int
vips_webpload_buffer_shrink(void *buf, size_t len, VipsImage **out, int shrink) {
	return vips_webpload_buffer(buf, len, out, "shrink", shrink, NULL);
}

int
vips_flip_bridge(VipsImage *in, VipsImage **out, int direction) {
	return vips_flip(in, out, direction, NULL);
}

int
vips_shrink_bridge(VipsImage *in, VipsImage **out, double xshrink, double yshrink) {
	return vips_shrink(in, out, xshrink, yshrink, NULL);
}

int
vips_reduce_bridge(VipsImage *in, VipsImage **out, double xshrink, double yshrink) {
	return vips_reduce(in, out, xshrink, yshrink, NULL);
}

int
vips_type_find_bridge(int t) {
	if (t == GIF) {
		return vips_type_find("VipsOperation", "gifload");
	}
	if (t == PDF) {
		return vips_type_find("VipsOperation", "pdfload");
	}
	if (t == TIFF) {
		return vips_type_find("VipsOperation", "tiffload");
	}
	if (t == SVG) {
		return vips_type_find("VipsOperation", "svgload");
	}
	if (t == WEBP) {
		return vips_type_find("VipsOperation", "webpload");
	}
	if (t == PNG) {
		return vips_type_find("VipsOperation", "pngload");
	}
	if (t == JPEG) {
		return vips_type_find("VipsOperation", "jpegload");
	}
	if (t == MAGICK) {
		return vips_type_find("VipsOperation", "magickload");
	}
	return 0;
}

int
vips_type_find_save_bridge(int t) {
	if (t == TIFF) {
		return vips_type_find("VipsOperation", "tiffsave_buffer");
	}
	if (t == WEBP) {
		return vips_type_find("VipsOperation", "webpsave_buffer");
	}
	if (t == PNG) {
		return vips_type_find("VipsOperation", "pngsave_buffer");
	}
	if (t == JPEG) {
		return vips_type_find("VipsOperation", "jpegsave_buffer");
	}
	return 0;
}

int
vips_rotate(VipsImage *in, VipsImage **out, int angle) {
	int rotate = VIPS_ANGLE_D0;

	angle %= 360;

	if (angle == 45) {
		rotate = VIPS_ANGLE45_D45;
	} else if (angle == 90) {
		rotate = VIPS_ANGLE_D90;
	} else if (angle == 135) {
		rotate = VIPS_ANGLE45_D135;
	} else if (angle == 180) {
		rotate = VIPS_ANGLE_D180;
	} else if (angle == 225) {
		rotate = VIPS_ANGLE45_D225;
	} else if (angle == 270) {
		rotate = VIPS_ANGLE_D270;
	} else if (angle == 315) {
		rotate = VIPS_ANGLE45_D315;
	} else {
		angle = 0;
	}

	if (angle > 0 && angle % 90 != 0) {
		return vips_rot45(in, out, "angle", rotate, NULL);
	} else {
		return vips_rot(in, out, rotate, NULL);
	}
}

int
vips_exif_orientation(VipsImage *image) {
	int orientation = 0;
	const char *exif;
	if (
		vips_image_get_typeof(image, EXIF_IFD0_ORIENTATION) != 0 &&
		!vips_image_get_string(image, EXIF_IFD0_ORIENTATION, &exif)
	) {
		orientation = atoi(&exif[0]);
	}
	return orientation;
}

int
interpolator_window_size(char const *name) {
	VipsInterpolate *interpolator = vips_interpolate_new(name);
	int window_size = vips_interpolate_get_window_size(interpolator);
	g_object_unref(interpolator);
	return window_size;
}

const char *
vips_enum_nick_bridge(VipsImage *image) {
	return vips_enum_nick(VIPS_TYPE_INTERPRETATION, image->Type);
}

int
vips_zoom_bridge(VipsImage *in, VipsImage **out, int xfac, int yfac) {
	return vips_zoom(in, out, xfac, yfac, NULL);
}

int
vips_embed_bridge(VipsImage *in, VipsImage **out, int left, int top, int width, int height, int extend, double r, double g, double b) {
	if (extend == VIPS_EXTEND_BACKGROUND) {
		double background[3] = {r, g, b};
		VipsArrayDouble *vipsBackground = vips_array_double_new(background, 3);
		return vips_embed(in, out, left, top, width, height, "extend", extend, "background", vipsBackground, NULL);
	}
	return vips_embed(in, out, left, top, width, height, "extend", extend, NULL);
}

int
vips_extract_area_bridge(VipsImage *in, VipsImage **out, int left, int top, int width, int height) {
	return vips_extract_area(in, out, left, top, width, height, NULL);
}

int
vips_colourspace_issupported_bridge(VipsImage *in) {
	return vips_colourspace_issupported(in) ? 1 : 0;
}

VipsInterpretation
vips_image_guess_interpretation_bridge(VipsImage *in) {
	return vips_image_guess_interpretation(in);
}

int
vips_colourspace_bridge(VipsImage *in, VipsImage **out, VipsInterpretation space) {
	return vips_colourspace(in, out, space, NULL);
}

int
vips_icc_transform_bridge (VipsImage *in, VipsImage **out, const char *output_icc_profile) {
	// `output_icc_profile` represents the absolute path to the output ICC profile file
	return vips_icc_transform(in, out, output_icc_profile, "embedded", TRUE, NULL);
}

int
vips_jpegsave_bridge(VipsImage *in, void **buf, size_t *len, int strip, int quality, int interlace) {
	return vips_jpegsave_buffer(in, buf, len,
		"strip", INT_TO_GBOOLEAN(strip),
		"Q", quality,
		"optimize_coding", TRUE,
		"interlace", INT_TO_GBOOLEAN(interlace),
		NULL
	);
}

int
vips_pngsave_bridge(VipsImage *in, void **buf, size_t *len, int strip, int compression, int quality, int interlace) {
#if (VIPS_MAJOR_VERSION >= 8 || (VIPS_MAJOR_VERSION >= 7 && VIPS_MINOR_VERSION >= 42))
	return vips_pngsave_buffer(in, buf, len,
		"strip", INT_TO_GBOOLEAN(strip),
		"compression", compression,
		"interlace", INT_TO_GBOOLEAN(interlace),
		"filter", VIPS_FOREIGN_PNG_FILTER_NONE,
		NULL
	);
#else
	return vips_pngsave_buffer(in, buf, len,
		"strip", INT_TO_GBOOLEAN(strip),
		"compression", compression,
		"interlace", INT_TO_GBOOLEAN(interlace),
		NULL
	);
#endif
}

int
vips_webpsave_bridge(VipsImage *in, void **buf, size_t *len, int strip, int quality, int lossless) {
	return vips_webpsave_buffer(in, buf, len,
		"strip", INT_TO_GBOOLEAN(strip),
		"Q", quality,
		"lossless", INT_TO_GBOOLEAN(lossless),
		NULL
	);
}

int
vips_tiffsave_bridge(VipsImage *in, void **buf, size_t *len) {
#if (VIPS_MAJOR_VERSION >= 8 && VIPS_MINOR_VERSION >= 5)
	return vips_tiffsave_buffer(in, buf, len, NULL);
#else
	return 0;
#endif
}

int
vips_is_16bit (VipsInterpretation interpretation) {
	return interpretation == VIPS_INTERPRETATION_RGB16 || interpretation == VIPS_INTERPRETATION_GREY16;
}

int
vips_flatten_background_brigde(VipsImage *in, VipsImage **out, double r, double g, double b) {
	if (vips_is_16bit(in->Type)) {
		r = 65535 * r / 255;
		g = 65535 * g / 255;
		b = 65535 * b / 255;
	}

	double background[3] = {r, g, b};
	VipsArrayDouble *vipsBackground = vips_array_double_new(background, 3);

	return vips_flatten(in, out,
		"background", vipsBackground,
		"max_alpha", vips_is_16bit(in->Type) ? 65535.0 : 255.0,
		NULL
	);
}

int
vips_init_image (void *buf, size_t len, int imageType, VipsImage **out) {
	int code = 1;

	if (imageType == JPEG) {
		code = vips_jpegload_buffer(buf, len, out, "access", VIPS_ACCESS_RANDOM, NULL);
	} else if (imageType == PNG) {
		code = vips_pngload_buffer(buf, len, out, "access", VIPS_ACCESS_RANDOM, NULL);
	} else if (imageType == WEBP) {
		code = vips_webpload_buffer(buf, len, out, "access", VIPS_ACCESS_RANDOM, NULL);
	} else if (imageType == TIFF) {
		code = vips_tiffload_buffer(buf, len, out, "access", VIPS_ACCESS_RANDOM, NULL);
#if (VIPS_MAJOR_VERSION >= 8)
#if (VIPS_MINOR_VERSION >= 3)
	} else if (imageType == GIF) {
		code = vips_gifload_buffer(buf, len, out, "access", VIPS_ACCESS_RANDOM, NULL);
	} else if (imageType == PDF) {
		code = vips_pdfload_buffer(buf, len, out, "access", VIPS_ACCESS_RANDOM, NULL);
	} else if (imageType == SVG) {
		code = vips_svgload_buffer(buf, len, out, "access", VIPS_ACCESS_RANDOM, NULL);
#endif
	} else if (imageType == MAGICK) {
		code = vips_magickload_buffer(buf, len, out, "access", VIPS_ACCESS_RANDOM, NULL);
#endif
	}

	return code;
}

int
vips_watermark_replicate (VipsImage *orig, VipsImage *in, VipsImage **out) {
	VipsImage *cache = vips_image_new();

	if (
		vips_replicate(in, &cache,
			1 + orig->Xsize / in->Xsize,
			1 + orig->Ysize / in->Ysize, NULL) ||
		vips_crop(cache, out, 0, 0, orig->Xsize, orig->Ysize, NULL)
	) {
		g_object_unref(cache);
		return 1;
	}

	g_object_unref(cache);
	return 0;
}

int
vips_watermark(VipsImage *in, VipsImage **out, WatermarkTextOptions *to, WatermarkOptions *o) {
	double ones[3] = { 1, 1, 1 };

	VipsImage *base = vips_image_new();
	VipsImage **t = (VipsImage **) vips_object_local_array(VIPS_OBJECT(base), 10);
	t[0] = in;

	// Make the mask.
	if (
		vips_text(&t[1], to->Text,
			"width", o->Width,
			"dpi", o->DPI,
			"font", to->Font,
			NULL) ||
		vips_linear1(t[1], &t[2], o->Opacity, 0.0, NULL) ||
		vips_cast(t[2], &t[3], VIPS_FORMAT_UCHAR, NULL) ||
		vips_embed(t[3], &t[4], 100, 100, t[3]->Xsize + o->Margin, t[3]->Ysize + o->Margin, NULL)
		) {
		g_object_unref(base);
		return 1;
	}

	// Replicate if necessary
	if (o->NoReplicate != 1) {
		VipsImage *cache = vips_image_new();
		if (vips_watermark_replicate(t[0], t[4], &cache)) {
			g_object_unref(cache);
			g_object_unref(base);
			return 1;
		}
		g_object_unref(t[4]);
		t[4] = cache;
	}

	// Make the constant image to paint the text with.
	if (
		vips_black(&t[5], 1, 1, NULL) ||
		vips_linear(t[5], &t[6], ones, o->Background, 3, NULL) ||
		vips_cast(t[6], &t[7], VIPS_FORMAT_UCHAR, NULL) ||
		vips_copy(t[7], &t[8], "interpretation", t[0]->Type, NULL) ||
		vips_embed(t[8], &t[9], 0, 0, t[0]->Xsize, t[0]->Ysize, "extend", VIPS_EXTEND_COPY, NULL)
		) {
		g_object_unref(base);
		return 1;
	}

	// Blend the mask and text and write to output.
	if (vips_ifthenelse(t[4], t[9], t[0], out, "blend", TRUE, NULL)) {
		g_object_unref(base);
		return 1;
	}

	g_object_unref(base);
	return 0;
}

int
vips_gaussblur_bridge(VipsImage *in, VipsImage **out, double sigma, double min_ampl) {
#if (VIPS_MAJOR_VERSION == 7 && VIPS_MINOR_VERSION < 41)
	return vips_gaussblur(in, out, (int) sigma, NULL);
#else
	return vips_gaussblur(in, out, sigma, NULL, "min_ampl", min_ampl, NULL);
#endif
}

int
vips_sharpen_bridge(VipsImage *in, VipsImage **out, int radius, double x1, double y2, double y3, double m1, double m2) {
#if (VIPS_MAJOR_VERSION == 7 && VIPS_MINOR_VERSION < 41)
	return vips_sharpen(in, out, radius, x1, y2, y3, m1, m2, NULL);
#else
	return vips_sharpen(in, out, "radius", radius, "x1", x1, "y2", y2, "y3", y3, "m1", m1, "m2", m2, NULL);
#endif
}

int
vips_add_band(VipsImage *in, VipsImage **out, double c) {
#if (VIPS_MAJOR_VERSION > 8 || (VIPS_MAJOR_VERSION >= 8 && VIPS_MINOR_VERSION >= 2))
	return vips_bandjoin_const1(in, out, c, NULL);
#else
	VipsImage *base = vips_image_new();
	if (
		vips_black(&base, in->Xsize, in->Ysize, NULL) ||
		vips_linear1(base, &base, 1, c, NULL)) {
			g_object_unref(base);
			return 1;
		}
	g_object_unref(base);
	return vips_bandjoin2(in, base, out, c, NULL);
#endif
}

int
vips_watermark_image(VipsImage *in, VipsImage *watermark, VipsImage **out, WatermarkImageOptions *o) {
	// Inspired by https://gist.github.com/jcupitt/abacc012e2991f332e8b

	VipsImage *base = vips_image_new();
	// These images will all be unreffed when context is unreffed.
	VipsImage **t = (VipsImage**) vips_object_local_array(VIPS_OBJECT(base), 18);

	if (has_alpha_channel(in) == 0) {
		vips_add_band(in, &t[0], 255.0);
		// Add at the end to unref input image when done.
		t[17] = in;
	} else {
		t[0] = in;
	}

	if (has_alpha_channel(watermark) == 0) {
		vips_add_band(watermark, &t[1], 255.0);
		// Add at the end to unref input image when done.
		t[18] = watermark;
	} else {
		t[1] = watermark;
	}

	// Place watermark image in the right place and size it to the size of the
	// image that should be watermarked. Necessary for following operations because
	// libvips enlarges images that are smaller than the other operand-image with
	// zero-pixels. This is especially bad for multiplications as we effectively get
	// a mask cutting out everything that's outside the smaller image.
	if( vips_embed(t[1], &t[2], o->Left, o->Top, t[0]->Xsize, t[0]->Ysize, NULL)) {

		g_object_unref(base);
		return 1;
	}

	// dst = in
	// src = watermark

	// Extract the alpha channels.
	//
	// dst_a255, src_a255
	//
	// ^^^^^^^^  ^^^^^^^^
	//    t3        t4
	if( vips_extract_band(t[0], &t[3], 3, NULL) ||
		vips_extract_band(t[2], &t[4], 3, NULL)) {

		g_object_unref(base);
		return 1;
	}

	// Extract the RGB bands.
	//
	// dst_rgb, src_rgb
	//
	// ^^^^^^^  ^^^^^^^
	//   t5       t6
	if( vips_extract_band(t[0], &t[5], 0, "n", 3, NULL ) ||
		vips_extract_band(t[2], &t[6], 0, "n", 3, NULL)) {

		g_object_unref(base);
		return 1;
	}

	// Compute normalized input alpha channels.
	//
	// dst_a = dst_a255 / 255, src_a = src_a255 / 255
	//
	// ^^^^^                   ^^^^^
	//  t7                      t8
	if( vips_linear1(t[3], &t[7], 1.0 / 255.0, 0.0, NULL) ||
		vips_linear1(t[4], &t[8], 1.0 / 255.0, 0.0, NULL)) {

		g_object_unref(base);
		return 1;
	}

	// Compute normalized output alpha channel:
	//
	// References:
	// - http://en.wikipedia.org/wiki/Alpha_compositing#Alpha_blending
	// - https://github.com/jcupitt/ruby-vips/issues/28#issuecomment-9014826
	//
	// out_a = src_a + dst_a * (1 - src_a)
	//
	//         ^^^^^   ^^^^^        ^^^^^
	//          t8      t7           t8
	//                         ^^^^^^^^^^^
	//                             t9
	// ^^^^^           ^^^^^^^^^^^^^^^^^^^
	//  t11                    t10

	if( vips_linear1(t[8], &t[9], -1.0, 1.0, NULL) ||
		vips_multiply(t[7], t[9], &t[10], NULL) ||
		vips_add(t[8], t[10], &t[11], NULL)) {

		g_object_unref(base);
		return 1;
	}

	// Compute output RGB channels:
	//
	// Wikipedia:
	//
	// out_rgb = (src_rgb * src_a + dst_rgb * dst_a * (1 - src_a)) / out_a
	//
	// ^^^^^^^    ^^^^^^^   ^^^^^   ^^^^^^^   ^^^^^        ^^^^^     ^^^^^
	//   t13        t6       t8       t5       t7           t8        t11
	//                              ^^^^^^^^^^^^^^^
	//                                    t12
	//
	// `vips_ifthenelse` with `blend=TRUE`:
	// https://jcupitt.github.io/libvips/API/current/libvips-conversion.html#vips-ifthenelse
	//
	// out = (cond / 255) * in1 + (1 - cond / 255) * in2
	//
	//        ^^^^                     ^^^^
	//          └───  src_a255 = t4  ───┘
	//
	// Substitutions:
	//
	//     cond --> src_a255 = t4
	//     in1 --> src_rgb = t6
	//     in2 --> dst_rgb * dst_a = t5 * t7 (premultiplied destination RGB)
	//
	// Division by `out_a` is not required as `vips_ifthenelse` doesn’t require
	// normalized inputs.

	if( vips_multiply(t[5], t[7], &t[12], NULL) ||
		vips_ifthenelse(t[4], t[6], t[12], &t[13], "blend", TRUE, NULL)) {

		g_object_unref(base);
		return 1;
	}

	// unnormalise the alpha, reattach
	if( vips_linear1(t[11], &t[14], 255.0, 0.0, "uchar", TRUE, NULL) ||
		vips_bandjoin2(t[13], t[14], &t[15], NULL)) {

		g_object_unref(base);
		return 1;
	}

	// Return a reference to the output image.
	g_object_ref(t[15]);
	*out = t[15];

	g_object_unref(base);
	return 0;
}

int
vips_smartcrop_bridge(VipsImage *in, VipsImage **out, int width, int height) {
#if (VIPS_MAJOR_VERSION >= 8 && VIPS_MINOR_VERSION >= 5)
	return vips_smartcrop(in, out, width, height, NULL);
#else
	return 0;
#endif
}

int vips_find_trim_bridge(VipsImage *in, int *top, int *left, int *width, int *height, double r, double g, double b, double threshold) {
#if (VIPS_MAJOR_VERSION >= 8 && VIPS_MINOR_VERSION >= 6)
	if (vips_is_16bit(in->Type)) {
		r = 65535 * r / 255;
		g = 65535 * g / 255;
		b = 65535 * b / 255;
	}

	double background[3] = {r, g, b};
	VipsArrayDouble *vipsBackground = vips_array_double_new(background, 3);
	return vips_find_trim(in, top, left, width, height, "background", vipsBackground, "threshold", threshold, NULL);
#else
	return 0;
#endif
}