Logic for Sep and DeviceN colorspaces with C,M,Y, or K.

Special care is required when the DeviceN color space has
cyan, magenta, yellow or black.

For example, even if we support separations in the destination, if
the color space has CMY or K as one of its colorants and we are
drawing to an RGB or Gray pixmap we will want to do the tint transform.

Also if the pixmap has no seps memember present, we support the
separations if the destination is CMYK and the DeviceN colorspace
has no "Spot" (non-CMYK) colorants.

1 files changed, 50 insertions, 6 deletions

diff --git a/source/fitz/colorspace.c b/source/fitz/colorspace.c
index 7ec34f06..414ef097 100644
--- a/source/fitz/colorspace.c
+++ b/source/fitz/colorspace.c
@@ -157,7 +157,7 @@ clamp_default(const fz_colorspace *cs, const float *src, float *dst)
 }
 
 fz_colorspace *
-fz_new_colorspace(fz_context *ctx, const char *name, int n, int is_subtractive, int is_device_n, fz_colorspace_convert_fn *to_ccs, fz_colorspace_convert_fn *from_ccs, fz_colorspace_base_fn *base, fz_colorspace_clamp_fn *clamp, fz_colorspace_destruct_fn *destruct, void *data, size_t size)
+fz_new_colorspace(fz_context *ctx, const char *name, int n, int is_subtractive, int device_n, fz_colorspace_convert_fn *to_ccs, fz_colorspace_convert_fn *from_ccs, fz_colorspace_base_fn *base, fz_colorspace_clamp_fn *clamp, fz_colorspace_destruct_fn *destruct, void *data, size_t size)
 {
 	fz_colorspace *cs = fz_malloc_struct(ctx, fz_colorspace);
 	FZ_INIT_KEY_STORABLE(cs, 1, fz_drop_colorspace_imp);
@@ -165,7 +165,7 @@ fz_new_colorspace(fz_context *ctx, const char *name, int n, int is_subtractive,
 	fz_strlcpy(cs->name, name ? name : "UNKNOWN", sizeof cs->name);
 	cs->n = n;
 	cs->is_subtractive = is_subtractive;
-	cs->is_device_n = is_device_n;
+	cs->device_n = device_n;
 	cs->to_ccs = to_ccs;
 	cs->from_ccs = from_ccs;
 	cs->get_base = base;
@@ -3412,7 +3412,7 @@ fz_new_indexed_colorspace(fz_context *ctx, fz_colorspace *base, int high, unsign
 	idx->high = high;
 
 	fz_try(ctx)
-		cs = fz_new_colorspace(ctx, "Indexed", 1, 0, 0, fz_colorspace_is_icc(ctx, fz_device_rgb(ctx)) ? indexed_to_alt : indexed_to_rgb, NULL, base_indexed, clamp_indexed, free_indexed, idx, sizeof(*idx) + (base->n * (idx->high + 1)) + base->size);
+		cs = fz_new_colorspace(ctx, "Indexed", 1, 0, FZ_NOT_DEVICE_N, fz_colorspace_is_icc(ctx, fz_device_rgb(ctx)) ? indexed_to_alt : indexed_to_rgb, NULL, base_indexed, clamp_indexed, free_indexed, idx, sizeof(*idx) + (base->n * (idx->high + 1)) + base->size);
 	fz_catch(ctx)
 	{
 		fz_free(ctx, idx);
@@ -3660,7 +3660,7 @@ fz_new_icc_colorspace(fz_context *ctx, const char *name, int num, fz_buffer *buf
 		}
 
 		fz_md5_icc(ctx, profile);
-		cs = fz_new_colorspace(ctx, name, num, 0, 0, NULL, NULL, NULL, is_lab ? clamp_lab_icc : clamp_default_icc, free_icc, profile, sizeof(profile));
+		cs = fz_new_colorspace(ctx, name, num, 0, FZ_NOT_DEVICE_N, NULL, NULL, NULL, is_lab ? clamp_lab_icc : clamp_default_icc, free_icc, profile, sizeof(profile));
 
 		switch(profile->num_devcomp)
 		{
@@ -3755,7 +3755,7 @@ fz_new_cal_colorspace(fz_context *ctx, const char *name, float *wp, float *bp, f
 	cal_data->n = num;
 
 	fz_try(ctx)
-		cs = fz_new_colorspace(ctx, "pdf-cal", num, 0, 0, NULL, NULL, NULL, NULL, free_cal, cal_data, sizeof(cal_data));
+		cs = fz_new_colorspace(ctx, "pdf-cal", num, 0, FZ_NOT_DEVICE_N, NULL, NULL, NULL, NULL, free_cal, cal_data, sizeof(cal_data));
 	fz_catch(ctx)
 	{
 		fz_free(ctx, cal_data);
@@ -3905,8 +3905,42 @@ void fz_colorspace_name_colorant(fz_context *ctx, fz_colorspace *cs, int i, cons
 	fz_free(ctx, cs->colorant[i]);
 	cs->colorant[i] = NULL;
 	if (name)
+	{
 		cs->colorant[i] = fz_strdup(ctx, name);
 
+		if (cs->device_n != FZ_NOT_DEVICE_N)
+		{
+			if (i == 0)
+			{
+				if (strcmp(name, "Cyan") == 0 ||
+					strcmp(name, "Magenta") == 0 ||
+					strcmp(name, "Yellow") == 0 ||
+					strcmp(name, "Black") == 0)
+				{
+					cs->device_n = FZ_DEVICE_N_CMYK_ONLY;
+				}
+			}
+			else
+			{
+				if (cs->device_n != FZ_DEVICE_N_WITH_CMYK)
+				{
+					if (strcmp(name, "Cyan") == 0 ||
+						strcmp(name, "Magenta") == 0 ||
+						strcmp(name, "Yellow") == 0 ||
+						strcmp(name, "Black") == 0)
+					{
+						if (cs->device_n == FZ_DEVICE_N_SPOTS_ONLY)
+							cs->device_n = FZ_DEVICE_N_WITH_CMYK;
+					}
+					else
+					{
+						if (cs->device_n == FZ_DEVICE_N_CMYK_ONLY)
+							cs->device_n = FZ_DEVICE_N_WITH_CMYK;
+					}
+				}
+			}
+		}
+	}
 }
 
 const char *fz_colorspace_colorant(fz_context *ctx, const fz_colorspace *cs, int i)
@@ -3919,5 +3953,15 @@ const char *fz_colorspace_colorant(fz_context *ctx, const fz_colorspace *cs, int
 
 int fz_colorspace_is_device_n(fz_context *ctx, const fz_colorspace *cs)
 {
-	return (cs && cs->is_device_n);
+	return (cs && cs->device_n != FZ_NOT_DEVICE_N);
 }
+
+int fz_colorspace_device_n_info(fz_context *ctx, const fz_colorspace *cs)
+{
+	return (cs == NULL ? 0 : cs->device_n);
+}
+
+int fz_colorspace_device_n_has_cmyk(fz_context *ctx, const fz_colorspace *cs)
+{
+	return (cs == NULL ? 0 : cs->device_n == FZ_DEVICE_N_WITH_CMYK || cs->device_n == FZ_DEVICE_N_CMYK_ONLY);
+}
\ No newline at end of file