Rename internal color conversion functions to reflect what they do.

We used to convert through the XYZ colorspace. For various reasons we
changed to convert through RGB instead, but the function names didn't
follow suit.

1 files changed, 14 insertions, 28 deletions

diff --git a/pdf/pdf_colorspace.c b/pdf/pdf_colorspace.c
index a98e649b..26be83d4 100644
--- a/pdf/pdf_colorspace.c
+++ b/pdf/pdf_colorspace.c
@@ -31,15 +31,8 @@ static inline float fung(float x)
 	return (108.0f / 841.0f) * (x - (4.0f / 29.0f));
 }
 
-static inline float invg(float x)
-{
-	if (x > 0.008856f)
-		return powf(x, 1.0f / 3.0f);
-	return (7.787f * x) + (16.0f / 116.0f);
-}
-
 static void
-lab_to_xyz(fz_colorspace *cs, float *lab, float *rgb)
+lab_to_rgb(fz_colorspace *cs, float *lab, float *rgb)
 {
 	/* input is in range (0..100, -128..127, -128..127) not (0..1, 0..1, 0..1) */
 	float lstar, astar, bstar, l, m, n, x, y, z, r, g, b;
@@ -61,22 +54,15 @@ lab_to_xyz(fz_colorspace *cs, float *lab, float *rgb)
 }
 
 static void
-xyz_to_lab(fz_colorspace *cs, float *xyz, float *lab)
+rgb_to_lab(fz_colorspace *cs, float *rgb, float *lab)
 {
-	float lstar, astar, bstar;
-	float yyn = xyz[1];
-	if (yyn < 0.008856f)
-		lstar = 116.0f * yyn * (1.0f / 3.0f) - 16.0f;
-	else
-		lstar = 903.3f * yyn;
-	astar = 500 * (invg(xyz[0]) - invg(xyz[1]));
-	bstar = 200 * (invg(xyz[1]) - invg(xyz[2]));
-	lab[0] = lstar;
-	lab[1] = astar;
-	lab[2] = bstar;
+	fz_warn("cannot convert into L*a*b colorspace");
+	lab[0] = rgb[0];
+	lab[1] = rgb[1];
+	lab[2] = rgb[2];
 }
 
-static fz_colorspace k_device_lab = { -1, "Lab", 3, lab_to_xyz, xyz_to_lab };
+static fz_colorspace k_device_lab = { -1, "Lab", 3, lab_to_rgb, rgb_to_lab };
 static fz_colorspace *fz_device_lab = &k_device_lab;
 
 /* Separation and DeviceN */
@@ -88,12 +74,12 @@ struct separation
 };
 
 static void
-separation_to_xyz(fz_colorspace *cs, float *color, float *xyz)
+separation_to_rgb(fz_colorspace *cs, float *color, float *rgb)
 {
 	struct separation *sep = cs->data;
 	float alt[FZ_MAX_COLORS];
 	pdf_eval_function(sep->tint, color, cs->n, alt, sep->base->n);
-	sep->base->to_xyz(sep->base, alt, xyz);
+	sep->base->to_rgb(sep->base, alt, rgb);
 }
 
 static void
@@ -146,7 +132,7 @@ load_separation(fz_colorspace **csp, pdf_xref *xref, fz_obj *array)
 	sep->tint = tint;
 
 	cs = fz_new_colorspace(n == 1 ? "Separation" : "DeviceN", n);
-	cs->to_xyz = separation_to_xyz;
+	cs->to_rgb = separation_to_rgb;
 	cs->free_data = free_separation;
 	cs->data = sep;
 
@@ -166,7 +152,7 @@ struct indexed
 };
 
 static void
-indexed_to_xyz(fz_colorspace *cs, float *color, float *xyz)
+indexed_to_rgb(fz_colorspace *cs, float *color, float *rgb)
 {
 	struct indexed *idx = cs->data;
 	float alt[FZ_MAX_COLORS];
@@ -175,7 +161,7 @@ indexed_to_xyz(fz_colorspace *cs, float *color, float *xyz)
 	i = CLAMP(i, 0, idx->high);
 	for (k = 0; k < idx->base->n; k++)
 		alt[k] = idx->lookup[i * idx->base->n + k] / 255.0f;
-	idx->base->to_xyz(idx->base, alt, xyz);
+	idx->base->to_rgb(idx->base, alt, rgb);
 }
 
 static void
@@ -197,7 +183,7 @@ pdf_expand_indexed_pixmap(fz_pixmap *src)
 	int y, x, k, n, high;
 	unsigned char *lookup;
 
-	assert(src->colorspace->to_xyz == indexed_to_xyz);
+	assert(src->colorspace->to_rgb == indexed_to_rgb);
 	assert(src->n == 2);
 
 	idx = src->colorspace->data;
@@ -258,7 +244,7 @@ load_indexed(fz_colorspace **csp, pdf_xref *xref, fz_obj *array)
 	memset(idx->lookup, 0, n);
 
 	cs = fz_new_colorspace("Indexed", 1);
-	cs->to_xyz = indexed_to_xyz;
+	cs->to_rgb = indexed_to_rgb;
 	cs->free_data = free_indexed;
 	cs->data = idx;