From 13f4229ee540e22a5f3ede4d345ae1269cd708d3 Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@mutantstargoat.com>
Date: Fri, 9 Feb 2018 03:03:47 +0200
Subject: [PATCH] adding fast blur function

---
 src/fract.c   |    3 ---
 src/gfxutil.c |   44 ++++++++++++++++++++++++++++++++++++++++++++
 src/gfxutil.h |    9 ++++++++-
 src/greets.c  |   10 +++++++---
 4 files changed, 59 insertions(+), 7 deletions(-)

diff --git a/src/fract.c b/src/fract.c
index a17550b..e082620 100644
--- a/src/fract.c
+++ b/src/fract.c
@@ -43,9 +43,6 @@ static void destroy(void)
 {
 }
 
-#define PACK_RGB16(r, g, b) \
-	(((((r) >> 3) & 0x1f) << 11) | ((((g) >> 2) & 0x3f) << 5) | (((b) >> 3) & 0x1f))
-
 static void draw(void)
 {
 	int i, j;
diff --git a/src/gfxutil.c b/src/gfxutil.c
index 0257f79..811915e 100644
--- a/src/gfxutil.c
+++ b/src/gfxutil.c
@@ -142,3 +142,47 @@ void draw_line(int x0, int y0, int x1, int y1, unsigned short color)
 		}
 	}
 }
+
+
+/* TODO bound blur rad to image size to avoid inner loop conditionals */
+/* TODO make version with pow2 (rad*2+1) to avoid div with count everywhere */
+void blur_grey_horiz(uint16_t *dest, uint16_t *src, int xsz, int ysz, int rad)
+{
+	int i, j;
+
+	for(i=0; i<ysz; i++) {
+		int sum = src[0] * (rad + 1);
+		int count = rad * 2 + 1;
+		uint16_t lastpix = src[xsz - 1];
+
+		/* add up the contributions for the -1 pixel */
+		for(j=0; j<rad; j++) {
+			sum += src[j];
+		}
+
+		/* first part adding src[rad] and subtracting src[0] */
+		for(j=0; j<rad; j++) {
+			sum += src[rad] - src[0];
+			++src;
+			*dest++ = sum / count;
+		}
+
+		/* middle part adding src[rad] and subtracting src[-(rad+1)] */
+		for(j=0; j<xsz - rad; j++) {
+			sum += src[rad] - src[-(rad + 1)];
+			++src;
+			*dest++ = sum / count;
+		}
+
+		/* last part adding lastpix and subtracting src[-(rad+1)] */
+		for(j=0; j<rad; j++) {
+			sum += lastpix - src[-(rad + 1)];
+			++src;
+			*dest++ = sum / count;
+		}
+	}
+}
+
+void blur_grey_vert(uint16_t *dest, uint16_t *src, int xsz, int ysz, int radius)
+{
+}
diff --git a/src/gfxutil.h b/src/gfxutil.h
index 603c11d..cf64487 100644
--- a/src/gfxutil.h
+++ b/src/gfxutil.h
@@ -1,8 +1,12 @@
 #ifndef GFXUTIL_H_
 #define GFXUTIL_H_
 
+#include "inttypes.h"
+
 #define PACK_RGB16(r, g, b) \
-	(((((r) >> 3) & 0x1f) << 11) | ((((g) >> 2) & 0x3f) << 5) | (((b) >> 3) & 0x1f))
+	(((((uint16_t)(r) >> 3) & 0x1f) << 11) | \
+	 ((((uint16_t)(g) >> 2) & 0x3f) << 5) | \
+	 (((uint16_t)(b) >> 3) & 0x1f))
 
 #define UNPACK_R16(c)	(((c) >> 8) & 0xf8)
 #define UNPACK_G16(c)	(((c) >> 3) & 0xfc)
@@ -14,4 +18,7 @@
 int clip_line(int *x0, int *y0, int *x1, int *y1, int xmin, int ymin, int xmax, int ymax);
 void draw_line(int x0, int y0, int x1, int y1, unsigned short color);
 
+void blur_grey_horiz(uint16_t *dest, uint16_t *src, int xsz, int ysz, int radius);
+void blur_grey_vert(uint16_t *dest, uint16_t *src, int xsz, int ysz, int radius);
+
 #endif	/* GFXUTIL_H_ */
diff --git a/src/greets.c b/src/greets.c
index 0876b60..9fa14df 100644
--- a/src/greets.c
+++ b/src/greets.c
@@ -30,7 +30,7 @@ struct vec3 {
 struct particle {
 	float x, y, z;
 	float vx, vy, vz;	/* velocity */
-	float r, g, b;
+	int r, g, b;
 	float life;
 };
 
@@ -203,7 +203,9 @@ int init_emitter(struct emitter *em, int num, unsigned char *map, int xsz, int y
 		p->x = (float)x / (float)xsz - 0.5;
 		p->y = -(float)y / (float)xsz + 0.5 / aspect;
 		p->z = ((float)i / (float)num * 2.0 - 1.0) * 0.005;
-		p->r = p->g = p->b = 0.9;
+		p->r = 0;
+		p->g = 0x1f;
+		p->b = 255;
 		p->vx = p->vy = p->vz = 0.0f;
 		p->life = MAX_LIFE;
 		++p;
@@ -233,7 +235,9 @@ void update_particles(struct emitter *em, float dt)
 		v->y = p->y;
 		v->z = p->z;
 		v->w = 1.0f;
-		v->r = v->g = v->b = 200;
+		v->r = p->r;
+		v->g = p->g;
+		v->b = p->b;
 		v->a = cround64(p->life * 255.0 / MAX_LIFE);
 		++v;
 
-- 
1.7.10.4