earthlike planet gen prototype

[blobs.git] / src / world / world.cpp

diff --git a/src/world/world.cpp b/src/world/world.cpp
index b872503c185b928df0d6175a0eb059c3518cbde6..57b080467690c30489b463f189693435a3f4be66 100644 (file)
--- a/src/world/world.cpp
+++ b/src/world/world.cpp
@@ -8,11 +8,15 @@
 #include "../const.hpp"
 #include "../app/Assets.hpp"
 #include "../graphics/Viewport.hpp"
+#include "../rand/OctaveNoise.hpp"
+#include "../rand/SimplexNoise.hpp"
 
 #include <algorithm>
 #include <cmath>
+#include <iostream>
 #include <glm/gtc/matrix_transform.hpp>
 #include <glm/gtx/euler_angles.hpp>
+#include <glm/gtx/io.hpp>
 #include <glm/gtx/transform.hpp>
 
 using blobs::G;
@@ -258,6 +262,14 @@ Planet::Planet(int sidelength)
 Planet::~Planet() {
 }
 
+glm::dvec3 Planet::TileCenter(int surface, int x, int y) const noexcept {
+       glm::dvec3 center(0.0f);
+       center[(surface + 0) % 3] = x + 0.5 - Radius();
+       center[(surface + 1) % 3] = y + 0.5 - Radius();
+       center[(surface + 2) % 3] = surface < 3 ? Radius() : -Radius();
+       return center;
+}
+
 void Planet::BuildVAOs() {
        vao.Bind();
        vao.BindAttributes();
@@ -268,7 +280,7 @@ void Planet::BuildVAOs() {
        vao.ReserveAttributes(TilesTotal() * 4, GL_STATIC_DRAW);
        {
                auto attrib = vao.MapAttributes(GL_WRITE_ONLY);
-               float offset = sidelength * 0.5f;
+               float offset = Radius();
 
                // srf  0  1  2  3  4  5
                //  up +Z +X +Y -Z -X -Y
@@ -361,7 +373,56 @@ void Planet::Draw(app::Assets &assets, graphics::Viewport &viewport) {
 }
 
 
-void GenerateTest(Planet &p) {
+void GenerateEarthlike(Planet &p) noexcept {
+       rand::SimplexNoise elevation_gen(0);
+
+       constexpr int ice = 0;
+       constexpr int grass = 3;
+       constexpr int water = 4;
+       constexpr int sand = 5;
+       constexpr int rock = 8;
+
+       constexpr double water_thresh = 0.0;
+       constexpr double beach_thresh = 0.1;
+       constexpr double mountain_thresh = 0.5;
+
+       const glm::dvec3 axis(glm::dvec4(0.0, 1.0, 0.0, 0.0) * glm::eulerAngleXY(p.SurfaceTilt().x, p.SurfaceTilt().y));
+       const double cap_thresh = std::cos(p.AxialTilt().x);
+
+       for (int surface = 0; surface <= 5; ++surface) {
+               for (int y = 0; y < p.SideLength(); ++y) {
+                       for (int x = 0; x < p.SideLength(); ++x) {
+                               glm::dvec3 to_tile = p.TileCenter(surface, x, y);
+                               double near_axis = std::abs(glm::dot(glm::normalize(to_tile), axis));
+                               if (near_axis > cap_thresh) {
+                                       p.TileAt(surface, x, y).type = ice;
+                                       continue;
+                               }
+                               float elevation = rand::OctaveNoise(
+                                       elevation_gen,
+                                       to_tile / p.Radius(),
+                                       3,   // octaves
+                                       0.5, // persistence
+                                       2 / p.Radius(), // frequency
+                                       2,   // amplitude
+                                       2    // growth
+                               );
+                               if (elevation < water_thresh) {
+                                       p.TileAt(surface, x, y).type = water;
+                               } else if (elevation < beach_thresh) {
+                                       p.TileAt(surface, x, y).type = sand;
+                               } else if (elevation < mountain_thresh) {
+                                       p.TileAt(surface, x, y).type = grass;
+                               } else {
+                                       p.TileAt(surface, x, y).type = rock;
+                               }
+                       }
+               }
+       }
+       p.BuildVAOs();
+}
+
+void GenerateTest(Planet &p) noexcept {
        for (int surface = 0; surface <= 5; ++surface) {
                for (int y = 0; y < p.SideLength(); ++y) {
                        for (int x = 0; x < p.SideLength(); ++x) {