From ade4f9c030633b0af20ea0b7ad74826d10ea4c05 Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Wed, 28 Sep 2022 19:18:04 +0200
Subject: [PATCH] ads-game:: ds-texture

---
 rogueviz/ads/ads-game.cpp   |   1 +
 rogueviz/ads/ds-game.cpp    |   8 ++
 rogueviz/ads/ds-texture.cpp | 167 ++++++++++++++++++++++++++++++++++++
 rogueviz/ads/globals.cpp    |   6 ++
 4 files changed, 182 insertions(+)
 create mode 100644 rogueviz/ads/ds-texture.cpp

diff --git a/rogueviz/ads/ads-game.cpp b/rogueviz/ads/ads-game.cpp
index 0e77f9f7..74298dda 100644
--- a/rogueviz/ads/ads-game.cpp
+++ b/rogueviz/ads/ads-game.cpp
@@ -9,6 +9,7 @@
 #include "display.cpp"
 #include "menu.cpp"
 #include "ds-game.cpp"
+#include "ds-texture.cpp"
 
 namespace hr {
 
diff --git a/rogueviz/ads/ds-game.cpp b/rogueviz/ads/ds-game.cpp
index 4f5fcff4..526342a5 100644
--- a/rogueviz/ads/ds-game.cpp
+++ b/rogueviz/ads/ds-game.cpp
@@ -2,6 +2,9 @@ namespace hr {
 
 namespace ads_game {
 
+void init_textures();
+void draw_textures();
+
 vector<ld> shape_disk;
 
 void set_default_keys();
@@ -199,6 +202,9 @@ auto future_shown = 3 * TAU;
 
 void init_ds_game() {
 
+  init_textures();
+  pick_textures();
+
   dynamicval<eGeometry> g(geometry, gSpace435);
 
   rockgen.cshift = 0;
@@ -404,6 +410,8 @@ transmatrix tpt(ld x, ld y) {
 
 void view_ds_game() {
   displayed.clear();
+  
+  draw_textures();
 
   main_rock->at.shift = current.shift;
 
diff --git a/rogueviz/ads/ds-texture.cpp b/rogueviz/ads/ds-texture.cpp
new file mode 100644
index 00000000..501bafed
--- /dev/null
+++ b/rogueviz/ads/ds-texture.cpp
@@ -0,0 +1,167 @@
+namespace hr {
+
+namespace ads_game {
+
+struct earth_texture {
+  string filename;
+  string copyright;
+  texture::texture_data tex;
+  basic_textureinfo tinf;
+  bool loaded;
+  };
+
+vector<earth_texture> earth_textures;
+
+struct texture_to_use {
+  ld from, ctr, to;
+  earth_texture *tx;
+  };
+
+vector<texture_to_use> textures_to_use;
+
+void init_textures() {
+  earth_textures.clear();
+  string dir = "ds-images/";
+  fhstream f(dir + "list.txt", "rt");
+  string cur_copyright = "";
+  while(!feof(f.f)) {
+    string s = scanline_noblank(f);
+    if(s == "") continue;
+    if(s[0] == '#') continue;
+    if(s[0] == '$') { cur_copyright = s.substr(1); continue; }
+    if(s.substr(0, 2) == "*/") s = dir + s.substr(2);
+    earth_textures.emplace_back();
+    auto& et = earth_textures.back();
+    println(hlog, "trying '", s, "'");
+    et.filename = s;
+    et.copyright = cur_copyright;
+    et.loaded = false;
+
+    auto& tex = et.tex;
+    tex.readtexture(s);
+    int tty = tex.theight - 2 * tex.base_y;
+    int u = 1;
+    for(int y=0; y<tex.theight; y++)
+    for(int x=0; x<tex.twidth; x++)
+      tex.get_texture_pixel(x, y) =
+      tex.get_texture_pixel(x, tex.base_y + u + gmod(y - tex.base_y - u, tty - u - u));
+    }
+  }
+
+void pick_textures() {
+  if(earth_textures.empty()) return;
+  bool first = !isize(textures_to_use);
+  auto last = first ? 0 : textures_to_use.back().to;
+  if(first || current.shift > last) {
+    auto et = &(earth_textures[hrand(isize(earth_textures))]);
+    textures_to_use.emplace_back();
+    auto& tu = textures_to_use.back();
+    auto& tex = et->tex;
+    ld ratio = tex.tx * 1. / tex.ty;
+    ld length = M_PI * ratio + 6;
+    ld t = first ? 0 : last + lerp(1, 3, randd()) + length;
+    tu.ctr = t;
+    tu.from = t - length;
+    tu.to = t + length;
+    tu.tx = et;
+    }
+  }
+
+ld smoothstep(ld x) {
+  if(x < 0) return 0;
+  if(x > 1) return 1;
+  return x * x * (3-2*x);
+  }
+
+void draw_texture(texture_to_use& tu) {
+  auto& et = *tu.tx;
+  auto& tex = et.tex;
+
+  if(!et.loaded) {
+    et.loaded = true;
+    tex.loadTextureGL();
+    et.tinf.texture_id = tex.textureid;
+    }
+  et.tinf.tvertices.clear();
+  
+  ld MWIDTH = tex.tx * .5 / tex.ty;
+  
+  println(hlog, "shift = ", current.shift, " end = ", tu.to);
+
+  auto add = [&] (int x, int y) {
+    ld x0 = (y-(YSCALE/2.)) / YSCALE * M_PI * 4;
+    ld mercator_y0 = (x-(XSCALE/2.)) / (XSCALE/2.) * M_PI * MWIDTH;
+    ld y0 = asin(tanh(2 * mercator_y0));
+    ld y1 = y0 - 90 * degree;
+    
+    et.tinf.tvertices.push_back(glhr::makevertex(x * 1. / XSCALE, .5 + (y-0.5) / MWIDTH / YSCALE, 0));
+
+    cross_result cr;
+    if(1) {
+      dynamicval<eGeometry> g(geometry, gSpace435);
+      ld s = current.shift - tu.ctr;
+
+      // We actually want to compute this, but this is not precise enough:
+      // cr = ds_cross0(current.T * lorentz(2, 3, -current.shift) * cspin(0, 1, x0) * cspin(0, 2, y0 - 90*degree));
+      
+      // Here is what we get for current.T == Id: (computed with sympy)      
+      hyperpoint now;
+      ld ts = tanh(s) * tanh(s);
+      ld cy = cos(y1) * cos(y1);
+      ld sq = sqrt(1 - cy * ts);
+      now[0] =  sin(y1) * cos(x0) / sq;
+      now[1] = -sin(x0) * sin(y1) / sq;
+      now[2] =  cos(y1) / cosh(s) / sq;
+      now[3] = 0;
+      
+      // And here is the derivative over t (t = the local variable from ds_cross0)
+      hyperpoint der;
+      sq = -sqrt(2)*tanh(s)/(4*sqrt(-cos(2*y1)*ts - ts + 2));
+      der[0] = sq*(sin(x0 - 2*y1) - sin(x0 + 2*y1));
+      der[1] = sq*(cos(x0 - 2*y1) - cos(x0 + 2*y1));
+      sq = sqrt(-cy*ts + 1);
+      der[2] =  (cy - 1)*sinh(s)/sq;
+      der[3] = -(cy*sinh(s)*tanh(s) - cosh(s))/sq;      
+      
+      cr.h = now;
+      
+      // now and der give us our wordline shifted to roughly the time of interest, so we can now use ds_cross0 safely
+      transmatrix U = Id;
+      set_column(U, 2, now);
+      set_column(U, 3, der);
+      cr = ds_cross0(current.T * U);
+      }
+
+    curvepoint(cr.h);
+    };
+
+  for(int x=0; x<XSCALE; x++)
+  for(int y=0; y<YSCALE; y++) {
+    add(x, y);
+    add(x+1, y);
+    add(x, y+1);
+    add(x+1, y);
+    add(x, y+1);
+    add(x+1, y+1);
+    }
+  
+  color_t col = 0xFFFFFFFF;
+  part(col, 0) = talpha;
+  part(col, 0) *= smoothstep(current.shift - tu.from);
+  part(col, 0) *= smoothstep(tu.to - current.shift);
+  
+  
+  auto& poly = queuecurve(shiftless(Id), 0, col, PPR::FLOOR);
+  poly.tinf = &et.tinf;
+  poly.flags |= POLY_TRIANGLES;
+  poly.offset_texture = 0;
+  }
+
+void draw_textures() {
+  pick_textures();
+  for(auto& tu: textures_to_use)
+    if(current.shift > tu.from && current.shift < tu.to)
+      draw_texture(tu);
+  }
+
+}}
diff --git a/rogueviz/ads/globals.cpp b/rogueviz/ads/globals.cpp
index 0d8f51c1..5aa99f6f 100644
--- a/rogueviz/ads/globals.cpp
+++ b/rogueviz/ads/globals.cpp
@@ -103,4 +103,10 @@ int draw_per_frame = 1000;
 
 ld ds_split_speed = 0.1;
 
+int XSCALE = 64;
+int YSCALE = 64;
+int talpha = 32;
+void init_textures();
+void pick_textures();
+void draw_textures();
 }}