X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=blobdiff_plain;f=src%2Fscr%2Ftunnel.c;fp=src%2Fscr%2Ftunnel.c;h=9071b74ea4a1cba12010c6bcd4c86c88bfff6da3;hb=ba648ddfc62fc6d3f47294aa8bfc10ea6ca3f479;hp=0000000000000000000000000000000000000000;hpb=3398fc6c4188104048f99b650a6cb90beda9b6ed;p=dosdemo

diff --git a/src/scr/tunnel.c b/src/scr/tunnel.c
new file mode 100644
index 0000000..9071b74
--- /dev/null
+++ b/src/scr/tunnel.c
@@ -0,0 +1,287 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <assert.h>
+#include "imago2.h"
+#include "demo.h"
+#include "screen.h"
+#include "gfxutil.h"
+
+#ifndef M_PI
+#define M_PI	3.1415926535
+#endif
+
+#define VSCALE	1.5
+
+#define TEX_FNAME	"data/grid.png"
+#define TEX_USCALE	4
+#define TEX_VSCALE	2
+
+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(unsigned short *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);
+
+static struct screen scr = {
+	"tunnel",
+	init,
+	destroy,
+	start,
+	stop,
+	draw
+};
+
+static int xsz, ysz, vxsz, vysz;
+static int pan_width, pan_height;
+static unsigned int *tunnel_map;
+static unsigned char *tunnel_fog;
+
+static int tex_xsz, tex_ysz;
+static unsigned int *tex_pixels;
+static int tex_xshift, tex_yshift;
+static unsigned int tex_xmask, tex_ymask;
+
+static long trans_start, trans_dur;
+static int trans_dir;
+
+
+struct screen *tunnel_screen(void)
+{
+	return &scr;
+}
+
+
+static int init(void)
+{
+	int i, j, n;
+	unsigned int *tmap;
+	unsigned char *fog;
+	float aspect = (float)fb_width / (float)fb_height;
+
+	xsz = fb_width;
+	ysz = fb_height;
+	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");
+		return -1;
+	}
+	if(!(tunnel_fog = malloc(vxsz * vysz))) {
+		fprintf(stderr, "failed to allocate tunnel fog map\n");
+		return -1;
+	}
+
+	tmap = tunnel_map;
+	fog = tunnel_fog;
+
+	for(i=0; i<vysz; i++) {
+		float y = 2.0 * (float)i / (float)vysz - 1.0;
+		for(j=0; j<vxsz; j++) {
+			float x = aspect * (2.0 * (float)j / (float)vxsz - 1.0);
+			float tu = atan2(y, x) / M_PI * 0.5 + 0.5;
+			float d = sqrt(x * x + y * y);
+			float tv = d == 0.0 ? 0.0 : 1.0 / d;
+
+			int tx = (int)(tu * 65535.0 * TEX_USCALE) & 0xffff;
+			int ty = (int)(tv * 65535.0 * TEX_VSCALE) & 0xffff;
+
+			int f = (int)(d * 192.0);
+
+			*tmap++ = (tx << 16) | ty;
+			*fog++ = f > 255 ? 255 : f;
+		}
+	}
+
+	if(!(tex_pixels = img_load_pixels(TEX_FNAME, &tex_xsz, &tex_ysz, IMG_FMT_RGBA32))) {
+		fprintf(stderr, "failed to load image " TEX_FNAME "\n");
+		return -1;
+	}
+	if((count_bits(tex_xsz) | count_bits(tex_ysz)) != 1) {
+		fprintf(stderr, "non-pow2 image (%dx%d)\n", tex_xsz, tex_ysz);
+		return -1;
+	}
+
+	/*tex_pixels = gen_test_image(&tex_xsz, &tex_ysz);*/
+
+	n = count_zeros(tex_xsz);
+	for(i=0; i<n; i++) {
+		tex_xmask |= 1 << i;
+	}
+	tex_xshift = n;
+
+	n = count_zeros(tex_ysz);
+	for(i=0; i<n; i++) {
+		tex_ymask |= 1 << i;
+	}
+	tex_yshift = n;
+
+	return 0;
+}
+
+static void destroy(void)
+{
+	free(tunnel_map);
+	free(tunnel_fog);
+	img_free_pixels(tex_pixels);
+}
+
+static void start(long trans_time)
+{
+	if(trans_time) {
+		trans_start = time_msec;
+		trans_dur = trans_time;
+		trans_dir = 1;
+	}
+}
+
+static void stop(long trans_time)
+{
+	if(trans_time) {
+		trans_start = time_msec;
+		trans_dur = trans_time;
+		trans_dir = -1;
+	}
+}
+
+#define NUM_WORK_ITEMS	8
+
+static void draw(void)
+{
+	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;
+		int progr = num_lines * interval / trans_dur;
+		if(trans_dir < 0) {
+			draw_lines = num_lines - progr - 1;
+		} else {
+			draw_lines = progr;
+		}
+		if(progr >= num_lines) {
+			trans_dir = 0;
+		}
+	}
+
+	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++) {
+		int starty = i * num_lines;
+		int resty = starty + draw_lines;
+		int rest_lines = num_lines - draw_lines;
+		draw_tunnel_range(fb_pixels, xoffs, yoffs, starty, draw_lines, time_msec);
+		if(rest_lines) {
+			memset(fb_pixels + resty * fb_width, 0, rest_lines * fb_width * 2);
+		}
+	}
+
+	swap_buffers(0);
+}
+
+static void tunnel_color(int *rp, int *gp, int *bp, long toffs, unsigned int tpacked, int fog)
+{
+	int r, g, b;
+	unsigned int col;
+	unsigned int tx = (((tpacked >> 16) & 0xffff) << tex_xshift) >> 16;
+	unsigned int ty = ((tpacked & 0xffff) << tex_yshift) >> 16;
+	tx += toffs;
+	ty += toffs << 1;
+
+	tx &= tex_xmask;
+	ty &= tex_ymask;
+
+	col = tex_pixels[(ty << tex_xshift) + tx];
+	r = col & 0xff;
+	g = (col >> 8) & 0xff;
+	b = (col >> 16) & 0xff;
+
+	*rp = (r * fog) >> 8;
+	*gp = (g * fog) >> 8;
+	*bp = (b * fog) >> 8;
+}
+
+static void draw_tunnel_range(unsigned short *pix, int xoffs, int yoffs, int starty, int num_lines, long tm)
+{
+	int i, j;
+	unsigned int *tmap = tunnel_map + (starty + yoffs) * vxsz + xoffs;
+	unsigned char *fog = tunnel_fog + (starty + yoffs) * vxsz + xoffs;
+
+	long toffs = tm / 8;
+	unsigned int *pixels = (unsigned int*)pix + starty * (fb_width >> 1);
+
+	for(i=0; i<num_lines; i++) {
+		for(j=0; j<(xsz>>1); j++) {
+			unsigned int col;
+			int r, g, b, idx = j << 1;
+
+			tunnel_color(&r, &g, &b, toffs, tmap[idx], fog[idx]);
+			col = PACK_RGB16(r, g, b);
+			tunnel_color(&r, &g, &b, toffs, tmap[idx + 1], fog[idx + 1]);
+			col |= PACK_RGB16(r, g, b) << 16;
+			*pixels++ = col;
+		}
+		tmap += vxsz;
+		fog += vxsz;
+	}
+}
+
+static int count_bits(unsigned int x)
+{
+	int i, nbits = 0;
+	for(i=0; i<32; i++) {
+		if(x & 1) ++nbits;
+		x >>= 1;
+	}
+	return nbits;
+}
+
+static int count_zeros(unsigned int x)
+{
+	int i, num = 0;
+	for(i=0; i<32; i++) {
+		if(x & 1) break;
+		++num;
+		x >>= 1;
+	}
+	return num;
+}
+
+/*
+static unsigned int *gen_test_image(int *wptr, int *hptr)
+{
+	int i, j;
+	int xsz = 256, ysz = 256;
+	unsigned int *pixels, *pix;
+
+	if(!(pixels = malloc(xsz * ysz * sizeof *pix))) {
+		return 0;
+	}
+	pix = pixels;
+
+	for(i=0; i<ysz; i++) {
+		for(j=0; j<xsz; j++) {
+			int val = i ^ j;
+
+			*pix++ = PACK_RGB32(val, val / 2, val / 4);
+		}
+	}
+
+	*wptr = xsz;
+	*hptr = ysz;
+	return pixels;
+}
+*/