From: John Tsiombikas <nuclear@mutantstargoat.com>
Date: Mon, 22 Aug 2016 04:31:31 +0000 (+0300)
Subject: better tunnel
X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=fbgfx;a=commitdiff_plain;h=3501fee68804c49c9f9f6effc1061eed3164e660

better tunnel
---

diff --git a/src/tunnel.c b/src/tunnel.c
index 8dec902..c331f2d 100644
--- a/src/tunnel.c
+++ b/src/tunnel.c
@@ -7,23 +7,22 @@
 #include "demo.h"
 #include "screen.h"
 
+#define VSCALE	1.5
+
 #define TEX_FNAME	"data/grid.png"
 #define TEX_USCALE	4
 #define TEX_VSCALE	2
 
-#define USCALE	2
-#define VSCALE	1
-
 static int init(void);
 static void destroy(void);
 static void start(long trans_time);
 static void stop(long trans_time);
 static void draw(void);
 
-static void (*draw_tunnel_range)(void*, int, int, long);
+static void (*draw_tunnel_range)(void*, int, int, int, int, long);
 
-static void draw_tunnel_range16(void *pixels, int starty, int num_lines, long tm);
-static void draw_tunnel_range32(void *pixels, int starty, int num_lines, long tm);
+static void draw_tunnel_range16(void *pixels, int xoffs, int yoffs, int starty, int num_lines, long tm);
+static void draw_tunnel_range32(void *pixels, int xoffs, int yoffs, int starty, int num_lines, long tm);
 static int count_bits(unsigned int x);
 static int count_zeros(unsigned int x);
 
@@ -37,6 +36,7 @@ static struct screen scr = {
 };
 
 static int xsz, ysz, vxsz, vysz;
+static int pan_width, pan_height;
 static unsigned int *tunnel_map;
 static unsigned char *tunnel_fog;
 
@@ -76,10 +76,13 @@ static int init(void)
 		return -1;
 	}
 
-	xsz = fb_width;
+	xsz = fb_width / 2;
 	ysz = fb_height;
-	vxsz = xsz / USCALE;
-	vysz = ysz / VSCALE;
+	vxsz = xsz * VSCALE;
+	vysz = ysz * VSCALE;
+
+	pan_width = vxsz - xsz;
+	pan_height = vysz - ysz;
 
 	if(!(tunnel_map = malloc(vxsz * vysz * sizeof *tunnel_map))) {
 		fprintf(stderr, "failed to allocate tunnel map\n");
@@ -104,7 +107,7 @@ static int init(void)
 			int tx = (int)(tu * 65535.0 * TEX_USCALE) & 0xffff;
 			int ty = (int)(tv * 65535.0 * TEX_VSCALE) & 0xffff;
 
-			int f = (int)(d * 95.0);
+			int f = (int)(d * 128.0);
 
 			*tmap++ = (tx << 16) | ty;
 			*fog++ = f > 255 ? 255 : f;
@@ -167,18 +170,21 @@ static struct work {
 	void *pixels;
 	int starty, num_lines;
 	long tm;
+	int xoffs, yoffs;
 } work[NUM_WORK_ITEMS];
 
 static void work_func(void *cls)
 {
 	struct work *w = (struct work*)cls;
-	draw_tunnel_range(w->pixels, w->starty, w->num_lines, w->tm);
+	draw_tunnel_range(w->pixels, w->xoffs, w->yoffs, w->starty, w->num_lines, w->tm);
 }
 
 static void draw(void)
 {
-	int i, num_lines = vysz / NUM_WORK_ITEMS;
+	int i, num_lines = ysz / NUM_WORK_ITEMS;
 	int draw_lines = num_lines;
+	float t;
+	int xoffs, yoffs;
 
 	if(trans_dir) {
 		long interval = time_msec - trans_start;
@@ -193,11 +199,17 @@ static void draw(void)
 		}
 	}
 
+	t = time_msec / 10000.0;
+	xoffs = (int)(cos(t * 3.0) * pan_width / 2) + pan_width / 2;
+	yoffs = (int)(sin(t * 4.0) * pan_height / 2) + pan_height / 2;
+
 	for(i=0; i<NUM_WORK_ITEMS; i++) {
 		work[i].pixels = fb_pixels;
 		work[i].starty = i * num_lines;
 		work[i].num_lines = draw_lines;
 		work[i].tm = time_msec;
+		work[i].xoffs = xoffs;
+		work[i].yoffs = yoffs;
 
 		tpool_enqueue(tpool, work + i, work_func, 0);
 	}
@@ -231,47 +243,51 @@ static void tunnel_color(int *rp, int *gp, int *bp, long toffs, unsigned int tpa
 #define PACK_RGB32(r, g, b) \
 	((((r) & 0xff) << 16) | (((g) & 0xff) << 8) | ((b) & 0xff))
 
-static void draw_tunnel_range16(void *pix, int starty, int num_lines, long tm)
+static void draw_tunnel_range16(void *pix, int xoffs, int yoffs, int starty, int num_lines, long tm)
 {
 	int i, j;
-	unsigned int *tmap = tunnel_map + starty * vxsz;
-	unsigned char *fog = tunnel_fog + starty * vxsz;
+	unsigned int *tmap = tunnel_map + (starty + yoffs) * vxsz + xoffs;
+	unsigned char *fog = tunnel_fog + (starty + yoffs) * vxsz + xoffs;
 
 	long toffs = tm / 4;
-	unsigned int *pixels = (unsigned int*)pix + starty * (xsz >> 1);
+	unsigned int *pixels = (unsigned int*)pix + starty * (fb_width >> 1);
 
 	for(i=0; i<num_lines; i++) {
-		for(j=0; j<vxsz; j++) {
+		for(j=0; j<xsz; j++) {
 			unsigned int col;
 			int r, g, b;
 
-			tunnel_color(&r, &g, &b, toffs, *tmap++, *fog++);
+			tunnel_color(&r, &g, &b, toffs, tmap[j], fog[j]);
 			col = PACK_RGB16(r, g, b);
 			*pixels++ = col;
 		}
+		tmap += vxsz;
+		fog += vxsz;
 	}
 }
 
-static void draw_tunnel_range32(void *pix, int starty, int num_lines, long tm)
+static void draw_tunnel_range32(void *pix, int xoffs, int yoffs, int starty, int num_lines, long tm)
 {
 	int i, j;
-	unsigned int *tmap = tunnel_map + starty * vxsz;
-	unsigned char *fog = tunnel_fog + starty * vxsz;
+	unsigned int *tmap = tunnel_map + (starty + yoffs) * vxsz + xoffs;
+	unsigned char *fog = tunnel_fog + (starty + yoffs) * vxsz + xoffs;
 
 	long toffs = tm / 4;
-	unsigned int *pixels = (unsigned int*)pix + starty * xsz * VSCALE;
+	unsigned int *pixels = (unsigned int*)pix + starty * fb_width;
 
 	for(i=0; i<num_lines; i++) {
-		for(j=0; j<vxsz; j++) {
+		for(j=0; j<xsz; j++) {
 			unsigned int col;
 			int r, g, b;
 
-			tunnel_color(&r, &g, &b, toffs, *tmap++, *fog++);
+			tunnel_color(&r, &g, &b, toffs, tmap[j], fog[j]);
 			col = PACK_RGB32(r, g, b);
 
 			*pixels++ = col;
 			*pixels++ = col;
 		}
+		tmap += vxsz;
+		fog += vxsz;
 	}
 }