3D Clouds

2 files changed, 61 insertions, 19 deletions

diff --git a/src/World/Clouds.cpp b/src/World/Clouds.cpp
index 6c5dba3..36f2441 100644
--- a/src/World/Clouds.cpp
+++ b/src/World/Clouds.cpp
@@ -1,15 +1,16 @@
 #include "Clouds.hpp"
 #include "../Math/MVP.hpp"
 #include "../Math/Perlin.hpp"
+#include "../Math/AABB.hpp"
+#include "../GFX/Util/Primitives.hpp"
 #include "../GFX/Util/MeshBuilder.hpp"
 #include <GL/glew.h>
 #include <array>
 
 namespace MC::World {
 
-Clouds::Clouds(Real ascept, Real fov, Real near, Real far, Vector<3, F32> sky_color)
-    : m_position(-1000, 120, -1000),
-    m_program(
+Clouds::Clouds(Real ascept, Real fov, Real near, Real far, Vector<3, F32> sky_color, Vector<3, F32> sun_direction)
+    : m_program(
     {GFX::Shading::Shader::Type::Vertex, vertex},
     {GFX::Shading::Shader::Type::Fragment, fragment}
     ),
@@ -21,24 +22,41 @@ Clouds::Clouds(Real ascept, Real fov, Real near, Real far, Vector<3, F32> sky_co
     m_view_uniform = m_program.uniform("view_matrix");
     m_projection_uniform = m_program.uniform("projection_matrix");
     auto sky_color_uniform = m_program.uniform("sky_color");
+    auto sun_direction_uniform = m_program.uniform("sun_direction");
 
     m_model_uniform.set(Math::MVP::model<F32>({}, {}, {}));
     m_view_uniform.set(Math::MVP::view<F32>({}, {}));
     m_projection_uniform.set(Math::MVP::perspective_projection<F32>(ascept, fov, near, far));
     sky_color_uniform.set(sky_color);
+    sun_direction_uniform.set(sun_direction);
 
     m_program.unbind();
 }
 
 void Clouds::update(U64 time) {
-    m_position.x() += time / 5000.0;
+    m_x_offset += time / 5000.0;
 }
 
 void Clouds::render(const GFX::Camera& camera) const {
+    auto position = camera.position();
+
+    I32 center_x = std::round((position.x() - m_x_offset) / TileSize);
+    I32 center_y = std::round(position.z() / TileSize);
+
+    for (Int x = -1; x <= 1; x++) {
+        for (Int y = -1; y <= 1; y++) {
+            render_single_instance(camera, center_x + x, center_y + y);
+        }
+    }
+}
+
+void Clouds::render_single_instance(const GFX::Camera& camera, Int x, Int y) const {
+    Vector<3> position{TileSize * x + m_x_offset, Height, TileSize * y};
+
     m_program.bind();
 
     m_view_uniform.set(Math::MVP::view<F32>(camera.position(), camera.angles()));
-    m_model_uniform.set(Math::MVP::model<F32>(m_position, Vector<3>{10.0}, {}));
+    m_model_uniform.set(Math::MVP::model<F32>(position, Vector<3>{Scale}, {}));
 
     m_mesh.bind();
     glDrawElements(GL_TRIANGLES, m_mesh.size(), GL_UNSIGNED_INT, nullptr);
@@ -51,8 +69,8 @@ Clouds::CloudMatrix Clouds::create_cloud_matrix() {
     Math::Perlin::Noise<2> noise{};
 
     CloudMatrix clouds{false};
-    for (Int x = 0; x < CloudMatrixSize; x++) {
-        for (Int y = 0; y < CloudMatrixSize; y++) {
+    for (Int x = 1; x < CloudMatrixSize; x++) {
+        for (Int y = 1; y < CloudMatrixSize; y++) {
             if (noise.at({x, y * 2}) > 0.55) {
                 clouds(x, y) = true;
             }
@@ -62,20 +80,31 @@ Clouds::CloudMatrix Clouds::create_cloud_matrix() {
 }
 
 GFX::Mesh Clouds::create_mesh(const CloudMatrix& cloud_matrix) {
-    GFX::Util::MeshBuilder builder{};
+    GFX::Util::MeshBuilder<Vector<3, F32>> builder{};
 
     for (Int x = 0; x < CloudMatrixSize; x++) {
         for (Int y = 0; y < CloudMatrixSize; y++) {
             if (!cloud_matrix(x, y)) continue;
 
-            U32 s = builder.vertex_count();
-            std::array<Vector<3, F32>, 4> positions = {{{0, 0, 0}, {1, 0, 0}, {0, 0, 1}, {1, 0, 1}}};
-            std::array<U32, 6> indices = { s + 0, s + 1, s + 2, s + 1, s + 3, s + 2 };
+            auto is_occupied = [&](Int xn, Int yn) {
+                if (xn < 0 || xn >= CloudMatrixSize || yn < 0 || yn >= CloudMatrixSize) return false;
+                return cloud_matrix(xn, yn);
+            };
+            std::array<bool, 4> neighbors = {
+                is_occupied(x - 1, y), is_occupied(x + 1, y),
+                is_occupied(x, y - 1), is_occupied(x, y + 1),
+            };
 
-            for (auto& p : positions) p += {x, 0, y};
+            using FaceSet = GFX::Util::Primitives::FaceSet;
+            U8 faces = FaceSet::Top | FaceSet::Bottom;
+            if (!neighbors[0]) faces |= FaceSet::Left;
+            if (!neighbors[1]) faces |= FaceSet::Right;
+            if (!neighbors[2]) faces |= FaceSet::Front;
+            if (!neighbors[3]) faces |= FaceSet::Back;
 
-            builder.positions(positions);
-            builder.indices(indices);
+            auto aabb = Math::AABB{{x, 0, y}, {x + 1, 1, y + 1}};
+            auto box = GFX::Util::Primitives::box(aabb, (FaceSet::Value)faces);
+            builder.primitive(box);
         }
     }
 
@@ -90,7 +119,9 @@ uniform mat4 view_matrix;
 uniform mat4 projection_matrix;
 
 layout (location = 0) in vec3 position;
+layout (location = 1) in vec3 normal;
 
+out vec3 surface_normal;
 out float depth;
 
 void main() {
@@ -99,7 +130,8 @@ void main() {
     vec4 clip_position = projection_matrix * view_position;
 
     gl_Position = clip_position;
-    depth = clamp((length(view_position) - 75) / 125, 0.0, 1.0);
+    surface_normal = (model_matrix * vec4(normal, 0.0)).xyz;
+    depth = clamp((length(view_position) - 200) / 400, 0.0, 1.0);
 }
 )v";
 
@@ -107,14 +139,18 @@ const Char* Clouds::fragment = R"f(
 #version 330 core
 
 uniform vec3 sky_color;
+uniform vec3 sun_direction;
 
+in vec3 surface_normal;
 in float depth;
 out vec4 color;
 
 void main() {
-    vec3 white = vec3(1.0, 1.0, 1.0);
+    float brightness = dot(normalize(surface_normal), normalize(-sun_direction));
+    vec3 diffuse = vec3(1 - clamp(brightness, -0.3, 0.2));
+    vec3 base = vec3(1.0, 1.0, 1.0) * diffuse;
 
-    color = vec4(mix(sky_color, white, 1 - depth), 0.5);
+    color = vec4(mix(sky_color, base, 1 - depth), 0.3);
 }
 )f";
 
diff --git a/src/World/Clouds.hpp b/src/World/Clouds.hpp
index 6a91901..b2d5a10 100644
--- a/src/World/Clouds.hpp
+++ b/src/World/Clouds.hpp
@@ -9,21 +9,27 @@ namespace MC::World {
 
 class Clouds {
 public:
-    Clouds(Real ascept, Real fov, Real near, Real far, Vector<3, F32> sky_color);
+    Clouds(Real ascept, Real fov, Real near, Real far, Vector<3, F32> sky_color, Vector<3, F32> sun_direction);
 
     void update(U64 time);
     void render(const GFX::Camera& camera) const;
 private:
     constexpr static U32 CloudMatrixSize = 128;
+    constexpr static Int Height = 200;
+    constexpr static Real Scale = 15;
+    constexpr static Real TileSize = CloudMatrixSize * Scale;
+
     using CloudMatrix = Matrix<CloudMatrixSize, CloudMatrixSize, Bool>;
 
+    void render_single_instance(const GFX::Camera& camera, Int x, Int y) const;
+
     static CloudMatrix create_cloud_matrix();
     static GFX::Mesh create_mesh(const CloudMatrix& cloud_matrix);
 
     static const Char* vertex;
     static const Char* fragment;
 
-    Vector<3> m_position;
+    Real m_x_offset = 0.0;
 
     GFX::Shading::Program m_program;
     GFX::BindableMesh m_mesh;