From 1d4da2ba1f23d28758116812aa0469f0dc21fb91 Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@member.fsf.org>
Date: Sat, 20 May 2023 16:06:17 +0300
Subject: [PATCH] wall noise and arbitrary render resolution option

---
 sdr/raydungeon.p.glsl |  136 ++++++++++++++++++++++++++++++++++++++++++++++++-
 src/level.c           |   12 ++---
 src/main.c            |    2 +-
 src/options.c         |   25 ++++++---
 src/options.h         |    2 +-
 src/scr_game.c        |   63 +++++++++++++++++++----
 src/scr_lvled.c       |    2 +-
 7 files changed, 216 insertions(+), 26 deletions(-)

diff --git a/sdr/raydungeon.p.glsl b/sdr/raydungeon.p.glsl
index c10be18..d6d8442 100644
--- a/sdr/raydungeon.p.glsl
+++ b/sdr/raydungeon.p.glsl
@@ -3,8 +3,8 @@ uniform mat4 matrix;
 uniform mat3 dirmatrix;
 
 #define DIST_THRES	1e-3
-#define MAX_ITER	250
-#define MAX_STEP	1.0
+#define MAX_ITER	128
+#define MAX_STEP	0.5
 
 vec3 raymarch(inout vec3 p, in vec3 dir, out float depth);
 vec3 shade(in vec3 p, in vec3 dir, in float dist, in float total_dist);
@@ -16,6 +16,12 @@ vec3 primray(in vec2 uv, out vec3 org);
 float boxdist(in vec3 p, in vec3 b);
 float sphdist(in vec3 p, in vec3 sp, in float srad);
 
+float fbm(vec3 v, int noct);
+float snoise(vec3 v);
+
+float eval_sdf_gen(in vec3 p);
+
+
 void main()
 {
 	vec2 uv = gl_TexCoord[0].st;
@@ -82,6 +88,11 @@ vec3 backdrop(in vec3 dir)
 	return vec3(0.1, 0.1, 0.1);
 }
 
+float eval_sdf(in vec3 p)
+{
+	return eval_sdf_gen(p) + fbm(p, 4) * 0.05;
+}
+
 #define DELTA	1e-4
 vec3 eval_grad(in vec3 p, float dist)
 {
@@ -115,3 +126,124 @@ float sphdist(in vec3 p, in vec3 sp, in float srad)
 {
 	return length(p - sp) - srad;
 }
+
+#ifdef TEST_SDF
+float eval_sdf_gen(in vec3 p)
+{
+	return boxdist(p - vec3(14.000000, 0.0, 14.000000), vec3(0.550000, 1.0, 4.550000));
+}
+#endif
+
+float fbm(vec3 v, int noct)
+{
+	float val = 0.0;
+	float f = 1.0;
+	for(int i=0; i<noct; i++) {
+		val += snoise(v * f) / f;
+		f *= 2.0;
+	}
+	return val;
+}
+
+// Description : Array and textureless GLSL 2D/3D/4D simplex 
+//               noise functions.
+//      Author : Ian McEwan, Ashima Arts.
+//  Maintainer : stegu
+//     Lastmod : 20201014 (stegu)
+//     License : Copyright (C) 2011 Ashima Arts. All rights reserved.
+//               Distributed under the MIT License. See LICENSE file.
+//               https://github.com/ashima/webgl-noise
+//               https://github.com/stegu/webgl-noise
+// 
+
+vec3 mod289(vec3 x) {
+	return x - floor(x * (1.0 / 289.0)) * 289.0;
+}
+
+vec4 mod289(vec4 x) {
+	return x - floor(x * (1.0 / 289.0)) * 289.0;
+}
+
+vec4 permute(vec4 x) {
+	return mod289(((x*34.0)+10.0)*x);
+}
+
+vec4 taylorInvSqrt(vec4 r)
+{
+	return 1.79284291400159 - 0.85373472095314 * r;
+}
+
+float snoise(vec3 v)
+{ 
+	const vec2  C = vec2(1.0/6.0, 1.0/3.0) ;
+	const vec4  D = vec4(0.0, 0.5, 1.0, 2.0);
+
+	// First corner
+	vec3 i  = floor(v + dot(v, C.yyy) );
+	vec3 x0 =   v - i + dot(i, C.xxx) ;
+
+	// Other corners
+	vec3 g = step(x0.yzx, x0.xyz);
+	vec3 l = 1.0 - g;
+	vec3 i1 = min( g.xyz, l.zxy );
+	vec3 i2 = max( g.xyz, l.zxy );
+
+	//   x0 = x0 - 0.0 + 0.0 * C.xxx;
+	//   x1 = x0 - i1  + 1.0 * C.xxx;
+	//   x2 = x0 - i2  + 2.0 * C.xxx;
+	//   x3 = x0 - 1.0 + 3.0 * C.xxx;
+	vec3 x1 = x0 - i1 + C.xxx;
+	vec3 x2 = x0 - i2 + C.yyy; // 2.0*C.x = 1/3 = C.y
+	vec3 x3 = x0 - D.yyy;      // -1.0+3.0*C.x = -0.5 = -D.y
+
+	// Permutations
+	i = mod289(i); 
+	vec4 p = permute( permute( permute( 
+					i.z + vec4(0.0, i1.z, i2.z, 1.0 ))
+				+ i.y + vec4(0.0, i1.y, i2.y, 1.0 )) 
+			+ i.x + vec4(0.0, i1.x, i2.x, 1.0 ));
+
+	// Gradients: 7x7 points over a square, mapped onto an octahedron.
+	// The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)
+	float n_ = 0.142857142857; // 1.0/7.0
+	vec3  ns = n_ * D.wyz - D.xzx;
+
+	vec4 j = p - 49.0 * floor(p * ns.z * ns.z);  //  mod(p,7*7)
+
+	vec4 x_ = floor(j * ns.z);
+	vec4 y_ = floor(j - 7.0 * x_ );    // mod(j,N)
+
+	vec4 x = x_ *ns.x + ns.yyyy;
+	vec4 y = y_ *ns.x + ns.yyyy;
+	vec4 h = 1.0 - abs(x) - abs(y);
+
+	vec4 b0 = vec4( x.xy, y.xy );
+	vec4 b1 = vec4( x.zw, y.zw );
+
+	//vec4 s0 = vec4(lessThan(b0,0.0))*2.0 - 1.0;
+	//vec4 s1 = vec4(lessThan(b1,0.0))*2.0 - 1.0;
+	vec4 s0 = floor(b0)*2.0 + 1.0;
+	vec4 s1 = floor(b1)*2.0 + 1.0;
+	vec4 sh = -step(h, vec4(0.0));
+
+	vec4 a0 = b0.xzyw + s0.xzyw*sh.xxyy ;
+	vec4 a1 = b1.xzyw + s1.xzyw*sh.zzww ;
+
+	vec3 p0 = vec3(a0.xy,h.x);
+	vec3 p1 = vec3(a0.zw,h.y);
+	vec3 p2 = vec3(a1.xy,h.z);
+	vec3 p3 = vec3(a1.zw,h.w);
+
+	//Normalise gradients
+	vec4 norm = taylorInvSqrt(vec4(dot(p0,p0), dot(p1,p1), dot(p2, p2), dot(p3,p3)));
+	p0 *= norm.x;
+	p1 *= norm.y;
+	p2 *= norm.z;
+	p3 *= norm.w;
+
+	// Mix final noise value
+	vec4 m = max(0.5 - vec4(dot(x0,x0), dot(x1,x1), dot(x2,x2), dot(x3,x3)), 0.0);
+	m = m * m;
+	return 105.0 * dot( m*m, vec4( dot(p0,x0), dot(p1,x1), 
+				dot(p2,x2), dot(p3,x3) ) );
+}
diff --git a/src/level.c b/src/level.c
index dd0e3a1..40df3e0 100644
--- a/src/level.c
+++ b/src/level.c
@@ -38,7 +38,7 @@ static int grow_rect(struct level *lvl, struct level_cell *orgcell, struct level
 	/* try expanding horizontally first */
 	cell = orgcell + 1;
 	x = ra.x + 1;
-	while(x < lvl->xsz && cell->type != CELL_SOLID) {
+	while(x++ < lvl->xsz && cell->type == CELL_SOLID) {
 		ra.w++;
 		cell++;
 	}
@@ -48,7 +48,7 @@ static int grow_rect(struct level *lvl, struct level_cell *orgcell, struct level
 	while(y++ < lvl->ysz) {
 		int rowsz = 0;
 		x = ra.x;
-		while(x++ < lvl->xsz && cell->type != CELL_SOLID) {
+		while(x++ < lvl->xsz && cell->type == CELL_SOLID) {
 			rowsz++;
 			cell++;
 		}
@@ -60,7 +60,7 @@ static int grow_rect(struct level *lvl, struct level_cell *orgcell, struct level
 	/* then try the same thing, but vertical first */
 	cell = orgcell + lvl->xsz;
 	y = rb.y + 1;
-	while(y++ < lvl->ysz && cell->type != CELL_SOLID) {
+	while(y++ < lvl->ysz && cell->type == CELL_SOLID) {
 		rb.h++;
 		cell += lvl->xsz;
 	}
@@ -70,7 +70,7 @@ static int grow_rect(struct level *lvl, struct level_cell *orgcell, struct level
 		int colsz = 0;
 		y = rb.y;
 		cell = lvl->cells + y * lvl->xsz + x;
-		while(y++ < lvl->ysz && cell->type != CELL_SOLID) {
+		while(y++ < lvl->ysz && cell->type == CELL_SOLID) {
 			colsz++;
 			cell += lvl->xsz;
 		}
@@ -113,7 +113,7 @@ void lvl_gen_rects(struct level *lvl)
 	cell = lvl->cells;
 	for(i=0; i<lvl->ysz; i++) {
 		for(j=0; j<lvl->xsz; j++) {
-			if(cell->type != CELL_SOLID && !cell->visited) {
+			if(cell->type == CELL_SOLID && !cell->visited) {
 				rect.x = j;
 				rect.y = i;
 				rect.w = rect.h = 1;
@@ -183,7 +183,7 @@ int save_level(const struct level *lvl, const char *fname)
 
 
 		fprintf(fp, "SDRSTART\n");
-		fprintf(fp, "float eval_sdf(in vec3 p)\n");
+		fprintf(fp, "float eval_sdf_gen(in vec3 p)\n");
 		fprintf(fp, "{\n");
 		rect = lvl->rects;
 		for(i=0; i<num; i++) {
diff --git a/src/main.c b/src/main.c
index beb3cf2..c0038dd 100644
--- a/src/main.c
+++ b/src/main.c
@@ -35,7 +35,7 @@ static PROC wgl_swap_interval_ext;
 int main(int argc, char **argv)
 {
 	glutInit(&argc, argv);
-	glutInitWindowSize(1280, 800);
+	glutInitWindowSize(1280, 720);
 	glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
 	glutCreateWindow("raydungeon");
 
diff --git a/src/options.c b/src/options.c
index b4964f9..38f6759 100644
--- a/src/options.c
+++ b/src/options.c
@@ -7,7 +7,7 @@
 #include "treestor.h"
 
 #define DEF_XRES		1280
-#define DEF_YRES		800
+#define DEF_YRES		720
 #define DEF_VSYNC		1
 #define DEF_VOL			255
 #define DEF_MUS			1
@@ -15,6 +15,7 @@
 #define DEF_INVMOUSEY	0
 #define DEF_MOUSE_SPEED	50
 
+#define DEF_GFX_RENDRES	1
 
 struct options opt = {
 	DEF_XRES, DEF_YRES,
@@ -24,6 +25,8 @@ struct options opt = {
 	DEF_MUS,
 	DEF_INVMOUSEY,
 	DEF_MOUSE_SPEED,
+
+	{ DEF_GFX_RENDRES }
 };
 
 int parse_options(int argc, char **argv)
@@ -81,6 +84,8 @@ int load_options(const char *fname)
 	opt.inv_mouse_y = ts_lookup_int(cfg, "options.controls.invmousey", DEF_INVMOUSEY);
 	opt.mouse_speed = ts_lookup_int(cfg, "options.controls.mousespeed", DEF_MOUSE_SPEED);
 
+	opt.gfx.render_res = ts_lookup_num(cfg, "options.gfx.render_res", DEF_GFX_RENDRES);
+
 	ts_free_tree(cfg);
 	return 0;
 }
@@ -88,23 +93,27 @@ int load_options(const char *fname)
 #define WROPT(lvl, fmt, val, defval) \
 	do { \
 		int i; \
+		if((val) == (defval)) fputc('#', fp); \
 		for(i=0; i<lvl; i++) fputc('\t', fp); \
-		if((val) == (defval)) { \
-			fprintf(fp, fmt "\t# default\n", val); \
-		} else { \
-			fprintf(fp, fmt "\n", val); \
-		} \
+		fprintf(fp, fmt "\n", val); \
 	} while(0)
 
 int save_options(const char *fname)
 {
 	FILE *fp;
+	static const char *hdr = "# Game options\n# ------------\n"
+		"# Lines starting with '#' are comments. Options set to their default value are\n"
+		"# automatically commented when this file is written. If you want to change some\n"
+		"# option, make sure to remove the '#' from the beginning of the line, or your\n"
+		"# change will have no effect.\n";
+
 
 	printf("writing config: %s\n", fname);
 
 	if(!(fp = fopen(fname, "wb"))) {
 		fprintf(stderr, "failed to save options (%s): %s\n", fname, strerror(errno));
 	}
+	fprintf(fp, "%s\n", hdr);
 	fprintf(fp, "options {\n");
 	fprintf(fp, "\tvideo {\n");
 	WROPT(2, "xres = %d", opt.xres, DEF_XRES);
@@ -113,6 +122,10 @@ int save_options(const char *fname)
 	WROPT(2, "fullscreen = %d", opt.fullscreen, DEF_FULLSCR);
 	fprintf(fp, "\t}\n");
 
+	fprintf(fp, "\tgfx {\n");
+	WROPT(2, "render_res = %f", opt.gfx.render_res, DEF_GFX_RENDRES);
+	fprintf(fp, "\t}\n");
+
 	fprintf(fp, "\taudio {\n");
 	WROPT(2, "volmaster = %d", opt.vol_master, DEF_VOL);
 	WROPT(2, "volmusic = %d", opt.vol_mus, DEF_VOL);
diff --git a/src/options.h b/src/options.h
index 179b35b..6beb3be 100644
--- a/src/options.h
+++ b/src/options.h
@@ -2,7 +2,7 @@
 #define OPTIONS_H_
 
 struct gfxoptions {
-	int foo;
+	float render_res;	/* 0.5 means render at half-res and scale by 2 */
 };
 
 struct options {
diff --git a/src/scr_game.c b/src/scr_game.c
index d19ff70..c5007bd 100644
--- a/src/scr_game.c
+++ b/src/scr_game.c
@@ -7,6 +7,7 @@
 #include "sdr.h"
 #include "level.h"
 #include "util.h"
+#include "options.h"
 
 static int ginit(void);
 static void gdestroy(void);
@@ -30,11 +31,15 @@ static struct level *lvl;
 
 static float proj_mat[16], view_mat[16];
 
-static float cam_theta, cam_phi = 20, cam_dist = 10;
+static float cam_theta, cam_phi, cam_dist;
 static cgm_vec3 cam_pan;
 
 static unsigned int sdr;
 
+static int rbuf_width, rbuf_height;
+static unsigned int fbo, rbuf_col, rbuf_zbuf;
+
+
 static int ginit(void)
 {
 	return 0;
@@ -42,6 +47,9 @@ static int ginit(void)
 
 static void gdestroy(void)
 {
+	glDeleteRenderbuffers(1, &rbuf_col);
+	glDeleteRenderbuffers(1, &rbuf_zbuf);
+	glDeleteFramebuffers(1, &fbo);
 }
 
 static int gstart(void)
@@ -51,16 +59,16 @@ static int gstart(void)
 	if(load_level(lvl, "data/test.lvl") == -1) {
 		return -1;
 	}
-	cam_pan.x = -(lvl->xsz / 2.0f) * lvl->scale;
+	cam_pan.x = -lvl->sx * lvl->scale;
 	cam_pan.y = 0;
-	cam_pan.z = -(lvl->ysz / 2.0f) * lvl->scale;
+	cam_pan.z = -lvl->sy * lvl->scale;
 
 	glEnable(GL_DEPTH_TEST);
 
 	if(lvl->sdf_src) {
 		add_shader_footer(GL_FRAGMENT_SHADER, lvl->sdf_src);
 	} else {
-		add_shader_footer(GL_FRAGMENT_SHADER, "float eval_sdf(in vec3 p) { return 10000.0; }\n");
+		add_shader_header(GL_FRAGMENT_SHADER, "#define TEST_SDF\n");
 	}
 	if(!(sdr = create_program_load("sdr/raydungeon.v.glsl", "sdr/raydungeon.p.glsl"))) {
 		return -1;
@@ -84,6 +92,9 @@ static void gdisplay(void)
 	float x, y;
 	struct level_cell *cell;
 
+	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+	glViewport(0, 0, rbuf_width, rbuf_height);
+
 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
 	cgm_mtranslation(view_mat, 0, 0, -cam_dist);
@@ -113,22 +124,56 @@ static void gdisplay(void)
 		for(j=0; j<lvl->xsz; j++) {
 			x = (float)j * lvl->scale;
 			if(cell->type) {
-				glVertex3f(x - 0.48, -1, y - 0.48);
-				glVertex3f(x + 0.48, -1, y - 0.48);
-				glVertex3f(x + 0.48, -1, y + 0.48);
-				glVertex3f(x - 0.48, -1, y + 0.48);
+				glVertex3f(x - 0.48 * lvl->scale, -1, y - 0.48 * lvl->scale);
+				glVertex3f(x + 0.48 * lvl->scale, -1, y - 0.48 * lvl->scale);
+				glVertex3f(x + 0.48 * lvl->scale, -1, y + 0.48 * lvl->scale);
+				glVertex3f(x - 0.48 * lvl->scale, -1, y + 0.48 * lvl->scale);
 			}
 			cell++;
 		}
 	}
 	glEnd();
+
+	glViewport(0, 0, win_width, win_height);
+	glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+	glBlitFramebuffer(0, 0, rbuf_width, rbuf_height, 0, 0, win_width, win_height,
+			GL_COLOR_BUFFER_BIT, GL_NEAREST);
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
 }
 
 static void greshape(int x, int y)
 {
-	cgm_mperspective(proj_mat, cgm_deg_to_rad(60), win_aspect, 0.5, 40.0);
+	cgm_mperspective(proj_mat, cgm_deg_to_rad(60), win_aspect, 0.5, 200.0);
 	glMatrixMode(GL_PROJECTION);
 	glLoadMatrixf(proj_mat);
+
+	rbuf_width = ((int)(x * opt.gfx.render_res) + 3) & 0xfffffc;
+	rbuf_height = ((int)(y * opt.gfx.render_res) + 3) & 0xfffffc;
+	printf("render buffer %dx%d\n", rbuf_width, rbuf_height);
+
+	if(!fbo) {
+		glGenFramebuffers(1, &fbo);
+		glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+
+		glGenRenderbuffers(1, &rbuf_col);
+		glBindRenderbuffer(GL_RENDERBUFFER, rbuf_col);
+		glRenderbufferStorage(GL_RENDERBUFFER, GL_RGB, rbuf_width, rbuf_height);
+		glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, rbuf_col);
+
+		glGenRenderbuffers(1, &rbuf_zbuf);
+		glBindRenderbuffer(GL_RENDERBUFFER, rbuf_zbuf);
+		glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, rbuf_width, rbuf_height);
+		glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, rbuf_zbuf);
+
+		glBindFramebuffer(GL_FRAMEBUFFER, 0);
+	} else {
+		glBindRenderbuffer(GL_RENDERBUFFER, rbuf_col);
+		glRenderbufferStorage(GL_RENDERBUFFER, GL_RGB, rbuf_width, rbuf_height);
+
+		glBindRenderbuffer(GL_RENDERBUFFER, rbuf_zbuf);
+		glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, rbuf_width, rbuf_height);
+	}
 }
 
 static void gkeyb(int key, int press)
diff --git a/src/scr_lvled.c b/src/scr_lvled.c
index 3b5eda3..70df9f5 100644
--- a/src/scr_lvled.c
+++ b/src/scr_lvled.c
@@ -118,7 +118,7 @@ static void reshape(int x, int y)
 {
 	float proj_mat[16];
 
-	cgm_mperspective(proj_mat, cgm_deg_to_rad(60), win_aspect, 0.5, 40.0);
+	cgm_mperspective(proj_mat, cgm_deg_to_rad(60), win_aspect, 0.5, 500.0);
 	glMatrixMode(GL_PROJECTION);
 	glLoadMatrixf(proj_mat);
 }
-- 
1.7.10.4