Add glow effects

Signed-off-by: Mattias Andrée <maandree@kth.se>

5 files changed, 54 insertions, 9 deletions

diff --git a/TODO b/TODO
index 50615d1..a7ba144 100644
--- a/TODO
+++ b/TODO
@@ -43,7 +43,7 @@ blind-from-video: add options to:
 
 blind-cone-gradient: add ability to make gradient superelliptic
 
-Add [-j jobs] to blind-from-video and blind-to-video.
+Add [-j jobs] to blind-from-video, blind-to-video, and blind-apply-kernel.
 
 long double is slightly faster than long.
 long double (xyza q) could be added as another format.
diff --git a/man/blind-gauss-blur.1 b/man/blind-gauss-blur.1
index 7b92045..d193f80 100644
--- a/man/blind-gauss-blur.1
+++ b/man/blind-gauss-blur.1
@@ -10,7 +10,7 @@ blind-gauss-blur - Apply Gaussian blur to a video
 |
 -s
 .RB ' auto ']
-[-achvy]
+[-acghvy]
 .I sd-stream
 .SH DESCRIPTION
 .B blind-gauss-blur
@@ -45,6 +45,9 @@ video is opaque.
 .B -c
 Blur the chroma only, not the luma.
 .TP
+.B -g
+Add glow effect.
+.TP
 .B -h
 Blur horizontally only. Has no affect if -v is also
 specified.
@@ -75,7 +78,9 @@ as the standard deviation all channels.
 .SH REQUIREMENTS
 .B blind-gauss-blur
 requires enough free memory to load three full frames into
-memory. A frame requires 32 bytes per pixel it contains.
+memory. A frame requires 32 bytes per pixel it contains. If
+.B -g
+is used, four full frames are required.
 .SH SEE ALSO
 .BR blind (7),
 .BR blind-single-colour (1),
diff --git a/man/blind-kernel.1 b/man/blind-kernel.1
index 9dc74a3..c19ba8c 100644
--- a/man/blind-kernel.1
+++ b/man/blind-kernel.1
@@ -61,12 +61,16 @@ is specified,
 .B SE
 is used.
 .TP
-.RI \fBgaussian\fP\ [-s\  spread ]\ [-u]\  standard-deviation
+.RI \fBgaussian\fP\ [-s\  spread ]\ [-g\ |\ -u]\  standard-deviation
 Creates a Gaussian blur kernel with the standard deviation
 .IR standard-deviation .
 If
 .B -u
-is used, the a Gaussian unsharpen kernel is created. If
+is used, the a Gaussian unsharpen kernel is created.
+If
+.B -g
+is used, the a Gaussian blur kernel with glow effect is created.
+If
 .B -s
 is specified, the specified
 .I spread
diff --git a/src/blind-gauss-blur.c b/src/blind-gauss-blur.c
index 66583df..983d6cd 100644
--- a/src/blind-gauss-blur.c
+++ b/src/blind-gauss-blur.c
@@ -1,16 +1,18 @@
 /* See LICENSE file for copyright and license details. */
 #include "common.h"
 
-USAGE("[-j jobs] [-s spread | -s 'auto'] [-achvy] sd-stream")
+USAGE("[-j jobs] [-s spread | -s 'auto'] [-acghvy] sd-stream")
 
 static int chroma = 0;
 static int noalpha = 0;
+static int glow = 0;
 static int vertical = 0;
 static int horizontal = 0;
 static int measure_y_only = 0;
 static int auto_spread = 0;
 static size_t jobs = 1;
 static size_t spread = 0;
+static void *original = NULL;
 
 /*
  * This is not a regular simple gaussian blur implementation.
@@ -126,6 +128,7 @@ static size_t spread = 0;
 		\
 		pixel_t *restrict clr = (pixel_t *)cbuf;\
 		pixel_t *restrict sig = (pixel_t *)sbuf;\
+		pixel_t *restrict orig = original;\
 		pixel_t *img = (pixel_t *)output;\
 		pixel_t c, k;\
 		size_t x1, y1, i1, x2, y2, i2;\
@@ -139,6 +142,8 @@ static size_t spread = 0;
 		x2end = colour->width;\
 		y2end = colour->height;\
 		\
+		if (glow)\
+			memcpy(orig, clr, colour->frame_size);\
 		if (chroma || !noalpha) {\
 			start = 0, end = colour->height;\
 			is_master = efork_jobs(&start, &end, jobs, &children);\
@@ -155,6 +160,12 @@ static size_t spread = 0;
 				}\
 			}\
 			\
+			/* store original image */\
+			if (glow) {\
+				i1 = start * colour->width;\
+				memcpy(orig + i1, clr + i1, (end - start) * colour->width * sizeof(*clr));\
+			}\
+			\
 			/* convert colour model */\
 			if (chroma) {\
 				i1 = start * colour->width;\
@@ -247,6 +258,19 @@ static size_t spread = 0;
 			}\
 		}\
 		\
+		/* apply glow */\
+		if (glow) {\
+			i1 = start * colour->width;\
+			for (y1 = start; y1 < end; y1++) {\
+				for (x1 = 0; x1 < colour->width; x1++, i1++) {\
+					img[i1][0] = 1 - (1 - img[i1][0]) * (1 - orig[i1][0]);\
+					img[i1][1] = 1 - (1 - img[i1][1]) * (1 - orig[i1][1]);\
+					img[i1][2] = 1 - (1 - img[i1][2]) * (1 - orig[i1][2]);\
+					img[i1][3] = 1 - (1 - img[i1][3]) * (1 - orig[i1][3]);\
+				}\
+			}\
+		}\
+		\
 		/* unpremultiply alpha channel */\
 		i1 = start * colour->width;\
 		for (y1 = start; y1 < end; y1++) {\
@@ -301,6 +325,9 @@ main(int argc, char *argv[])
 	case 'c':
 		chroma = 1;
 		break;
+	case 'g':
+		glow = 1;
+		break;
 	case 'h':
 		horizontal = 1;
 		break;
@@ -340,8 +367,12 @@ main(int argc, char *argv[])
 	if (jobs > colour.height)
 		jobs = colour.height;
 
+	if (glow)
+		original = emalloc(colour.frame_size);
+
 	fprint_stream_head(stdout, &colour);
 	efflush(stdout, "<stdout>");
 	process_each_frame_two_streams(&colour, &sigma, STDOUT_FILENO, "<stdout>", process);
+	free(original);
 	return 0;
 }
diff --git a/src/blind-kernel.c b/src/blind-kernel.c
index 8d0382e..352cede 100644
--- a/src/blind-kernel.c
+++ b/src/blind-kernel.c
@@ -223,13 +223,16 @@ kernel_gaussian(int argc, char *argv[], size_t *rows, size_t *cols, double **fre
 {
 	size_t spread = 0, y, x;
 	ssize_t xx, yy;
-	int unsharpen = 0;
+	int unsharpen = 0, glow = 0;
 	double sigma, value, c, k;
 	char *arg;
 
 #define argv0 arg
 	argc++, argv--;
 	ARGBEGIN {
+	case 'g':
+		glow = 1;
+		break;
 	case 's':
 		if (!(arg = ARGF()))
 			goto usage;
@@ -243,7 +246,7 @@ kernel_gaussian(int argc, char *argv[], size_t *rows, size_t *cols, double **fre
 	} ARGEND;
 #undef argv0
 
-	if (argc != 1)
+	if (argc != 1 || (unsharpen && glow))
 		goto usage;
 
 	sigma = etolf_arg("standard-deviation", argv[0]);
@@ -270,11 +273,13 @@ kernel_gaussian(int argc, char *argv[], size_t *rows, size_t *cols, double **fre
 
 	if (unsharpen)
 		(*free_this)[spread * *cols + spread] -= 2.0;
+	if (glow)
+		(*free_this)[spread * *cols + spread] += 1;
 
 	return *free_this;
 
 usage:
-	eprintf(SUBUSAGE("'gaussian' [-s spread] [-u] standard-deviation"));
+	eprintf(SUBUSAGE("'gaussian' [-s spread] [-g | -u] standard-deviation"));
 	return NULL;
 }