From 61de1fe7e510fdd425686c478439209f6f7a4b73 Mon Sep 17 00:00:00 2001
From: Tor Andersson <tor.andersson@artifex.com>
Date: Wed, 20 Aug 2014 11:33:55 +0200
Subject: Add full-page color tinting option and key binding to X11 viewer.

win32 supports tinting, but cannot change the color from the default.
---
 docs/man/mupdf.1            |  6 ++++++
 include/mupdf/fitz/pixmap.h |  9 +++++++++
 platform/x11/pdfapp.c       | 10 ++++++++++
 platform/x11/pdfapp.h       |  1 +
 platform/x11/x11_main.c     | 18 ++++++++++++++++-
 source/fitz/pixmap.c        | 47 +++++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 90 insertions(+), 1 deletion(-)

diff --git a/docs/man/mupdf.1 b/docs/man/mupdf.1
index 5831c0cc..44a6a600 100644
--- a/docs/man/mupdf.1
+++ b/docs/man/mupdf.1
@@ -29,6 +29,10 @@ The default value is 72.
 .B \-b bits
 Changes the anti-aliasing quality, specified as a number of bits between 0
 (off) and 8 (best). The default value is 8.
+.TP
+.B \-C RRGGBB
+Sets the full-page tint using hexadecimal color syntax. The default value
+is FFFAF0.
 
 .SH MOUSE BEHAVIOR
 
@@ -120,6 +124,8 @@ Toggle presentation mode.
 .B c
 Toggle between color and grayscale rendering.
 .TP
+.B C
+Toggle full-page color tinting.
 .B i
 Toggle between normal and inverted color rendering.
 .TP
diff --git a/include/mupdf/fitz/pixmap.h b/include/mupdf/fitz/pixmap.h
index 8be72914..800effd0 100644
--- a/include/mupdf/fitz/pixmap.h
+++ b/include/mupdf/fitz/pixmap.h
@@ -191,6 +191,15 @@ void fz_clear_pixmap(fz_context *ctx, fz_pixmap *pix);
 */
 void fz_invert_pixmap(fz_context *ctx, fz_pixmap *pix);
 
+/*
+	fz_tint_pixmap: Tint all the pixels in an RGB or Gray pixmap.
+
+	Multiplies all the samples with the input color argument.
+
+	r,g,b: The color to tint with, in 0 to 255 range.
+*/
+void fz_tint_pixmap(fz_context *ctx, fz_pixmap *pix, int r, int g, int b);
+
 /*
 	fz_invert_pixmap: Invert all the pixels in a given rectangle of a
 	pixmap. All components of all pixels in the rectangle are inverted
diff --git a/platform/x11/pdfapp.c b/platform/x11/pdfapp.c
index 00f085a4..4f05a496 100644
--- a/platform/x11/pdfapp.c
+++ b/platform/x11/pdfapp.c
@@ -122,6 +122,9 @@ void pdfapp_init(fz_context *ctx, pdfapp_t *app)
 #else
 	app->colorspace = fz_device_rgb(ctx);
 #endif
+	app->tint_r = 255;
+	app->tint_g = 250;
+	app->tint_b = 240;
 }
 
 void pdfapp_invert(pdfapp_t *app, const fz_rect *rect)
@@ -820,6 +823,8 @@ static void pdfapp_showpage(pdfapp_t *app, int loadpage, int drawpage, int repai
 		}
 		if (app->invert)
 			fz_invert_pixmap(app->ctx, app->image);
+		if (app->tint)
+			fz_tint_pixmap(app->ctx, app->image, app->tint_r, app->tint_g, app->tint_b);
 	}
 
 	if (transition)
@@ -1116,6 +1121,11 @@ void pdfapp_onkey(pdfapp_t *app, int c)
 		pdfapp_showpage(app, 0, 1, 1, 0, 0);
 		break;
 
+	case 'C':
+		app->tint ^= 1;
+		pdfapp_showpage(app, 0, 1, 1, 0, 0);
+		break;
+
 	case 'c':
 		app->grayscale ^= 1;
 		pdfapp_showpage(app, 0, 1, 1, 0, 0);
diff --git a/platform/x11/pdfapp.h b/platform/x11/pdfapp.h
index b2ff78da..81211181 100644
--- a/platform/x11/pdfapp.h
+++ b/platform/x11/pdfapp.h
@@ -64,6 +64,7 @@ struct pdfapp_s
 	int grayscale;
 	fz_colorspace *colorspace;
 	int invert;
+	int tint, tint_r, tint_g, tint_b;
 
 	/* presentation mode */
 	int presentation_mode;
diff --git a/platform/x11/x11_main.c b/platform/x11/x11_main.c
index d3f3d368..908850eb 100644
--- a/platform/x11/x11_main.c
+++ b/platform/x11/x11_main.c
@@ -791,6 +791,7 @@ static void usage(void)
 	fprintf(stderr, "\t-b -\tset anti-aliasing quality in bits (0=off, 8=best)\n");
 	fprintf(stderr, "\t-p -\tpassword\n");
 	fprintf(stderr, "\t-r -\tresolution\n");
+	fprintf(stderr, "\t-C -\tRRGGBB (tint color in hexadecimal syntax)\n");
 	exit(1);
 }
 
@@ -811,6 +812,7 @@ int main(int argc, char **argv)
 	struct timeval now;
 	struct timeval *timeout;
 	struct timeval tmo_advance_delay;
+	int tint, tint_r, tint_g, tint_b;
 
 	ctx = fz_new_context(NULL, NULL, FZ_STORE_DEFAULT);
 	if (!ctx)
@@ -819,10 +821,17 @@ int main(int argc, char **argv)
 		exit(1);
 	}
 
-	while ((c = fz_getopt(argc, argv, "p:r:b:")) != -1)
+	while ((c = fz_getopt(argc, argv, "p:r:b:C:")) != -1)
 	{
 		switch (c)
 		{
+		case 'C':
+			c = strtol(fz_optarg, NULL, 16);
+			tint = 1;
+			tint_r = (c >> 16) & 255;
+			tint_g = (c >> 8) & 255;
+			tint_b = (c) & 255;
+			break;
 		case 'p': password = fz_optarg; break;
 		case 'r': resolution = atoi(fz_optarg); break;
 		case 'b': fz_set_aa_level(ctx, atoi(fz_optarg)); break;
@@ -839,6 +848,13 @@ int main(int argc, char **argv)
 		pageno = atoi(argv[fz_optind++]);
 
 	pdfapp_init(ctx, &gapp);
+	if (tint)
+	{
+		gapp.tint = tint;
+		gapp.tint_r = tint_r;
+		gapp.tint_g = tint_g;
+		gapp.tint_b = tint_b;
+	}
 
 	winopen();
 
diff --git a/source/fitz/pixmap.c b/source/fitz/pixmap.c
index a56fdbd9..9ce8ffba 100644
--- a/source/fitz/pixmap.c
+++ b/source/fitz/pixmap.c
@@ -414,6 +414,53 @@ fz_alpha_from_gray(fz_context *ctx, fz_pixmap *gray, int luminosity)
 	return alpha;
 }
 
+void
+fz_tint_pixmap(fz_context *ctx, fz_pixmap *pix, int r, int g, int b)
+{
+	unsigned char *s = pix->samples;
+	int x, y;
+
+	if (pix->colorspace == fz_device_bgr(ctx))
+	{
+		int save = r;
+		r = b;
+		b = save;
+	}
+	else if (pix->colorspace == fz_device_gray(ctx))
+	{
+		g = (r + g + b) / 3;
+	}
+	else if (pix->colorspace != fz_device_rgb(ctx))
+	{
+		fz_throw(ctx, FZ_ERROR_GENERIC, "can only tint RGB, BGR and Gray pixmaps");
+	}
+
+	if (pix->n == 4)
+	{
+		for (x = 0; x < pix->w; x++)
+		{
+			for (y = 0; y < pix->h; y++)
+			{
+				s[0] = fz_mul255(s[0], r);
+				s[1] = fz_mul255(s[1], g);
+				s[2] = fz_mul255(s[2], b);
+				s += 4;
+			}
+		}
+	}
+	else if (pix->n == 2)
+	{
+		for (x = 0; x < pix->w; x++)
+		{
+			for (y = 0; y < pix->h; y++)
+			{
+				*s = fz_mul255(*s, g);
+				s += 2;
+			}
+		}
+	}
+}
+
 void
 fz_invert_pixmap(fz_context *ctx, fz_pixmap *pix)
 {
-- 
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