Merge branch 'separate-water'

1 files changed, 110 insertions, 0 deletions

diff --git a/game/water.cpp b/game/water.cpp
new file mode 100644
index 0000000..f720e3e
--- /dev/null
+++ b/game/water.cpp
@@ -0,0 +1,110 @@
+#include "water.h"
+#include "game/geoData.h"
+#include "gfx/models/texture.h"
+#include <algorithm>
+#include <cstddef>
+#include <gfx/gl/sceneShader.h>
+#include <gfx/gl/shadowMapper.h>
+#include <gfx/image.h>
+#include <gfx/models/mesh.h>
+#include <gfx/models/vertex.h>
+#include <glm/glm.hpp>
+#include <location.h>
+#include <maths.h>
+#include <set>
+#include <utility>
+#include <vector>
+
+namespace glm {
+	bool
+	operator<(const GlobalPosition2D a, const GlobalPosition2D b)
+	{
+		return std::tie(a.x, a.y) < std::tie(b.x, b.y);
+	}
+}
+
+template<>
+VertexArrayObject &
+VertexArrayObject::addAttribsFor<Water::Vertex>(const GLuint arrayBuffer, const GLuint divisor)
+{
+	return addAttribs<Water::Vertex, &Water::Vertex::pos>(arrayBuffer, divisor);
+}
+
+Water::Water(std::shared_ptr<GeoData> tm) : geoData {std::move(tm)}, water {std::make_shared<Texture>("water.png")}
+{
+	generateMeshes();
+}
+
+static constexpr GlobalDistance MIN_HEIGHT = 1'000;
+static constexpr GlobalDistance TILE_SIZE = 8'192;
+static constexpr GlobalDistance BORDER = TILE_SIZE / 2;
+
+void
+Water::generateMeshes()
+{
+	// Map out where a water square needs to exist to cover all terrain faces with a low vertex
+	std::set<GlobalPosition2D> waterPositions;
+	std::for_each(geoData->vertices_sbegin(), geoData->vertices_end(), [this, &waterPositions](const auto vh) {
+		if (geoData->point(vh).z < MIN_HEIGHT) {
+			std::for_each(geoData->vf_begin(vh), geoData->vf_end(vh),
+					[done = std::set<OpenMesh::FaceHandle>(), this, &waterPositions](const auto fh) mutable {
+						if (done.insert(fh).second) {
+							const auto getrange = [this, fh](glm::length_t axis) {
+								const auto mme = std::minmax_element(geoData->fv_begin(fh), geoData->fv_end(fh),
+										[this, axis](const auto vh1, const auto vh2) {
+											return geoData->point(vh1)[axis] < geoData->point(vh2)[axis];
+										});
+
+								return std::make_pair((geoData->point(*mme.first)[axis] - BORDER) / TILE_SIZE,
+										(geoData->point(*mme.second)[axis] + BORDER) / TILE_SIZE);
+							};
+							const auto xrange = getrange(0);
+							const auto yrange = getrange(1);
+							for (auto x = xrange.first; x < xrange.second; x++) {
+								for (auto y = yrange.first; y < yrange.second; y++) {
+									waterPositions.emplace(x, y);
+								}
+							}
+						}
+					});
+		}
+	});
+
+	std::vector<unsigned int> indices;
+	std::vector<Vertex> vertices;
+	std::map<GlobalPosition2D, size_t> vertexIndex;
+	std::for_each(waterPositions.begin(), waterPositions.end(),
+			[&indices, &vertices, &vertexIndex, extents = geoData->getExtents(), this](const GlobalPosition2D p) {
+				std::array<unsigned int, 4> currentIndices {};
+				auto out = currentIndices.begin();
+				for (auto x : {0, TILE_SIZE}) {
+					for (auto y : {0, TILE_SIZE}) {
+						const auto pos = (p * TILE_SIZE) + GlobalPosition2D {x, y};
+						const auto v = vertexIndex.emplace(pos, vertices.size());
+						if (v.second) {
+							const auto cpos = glm::clamp(pos, std::get<0>(extents).xy(), std::get<1>(extents).xy());
+							vertices.emplace_back(geoData->positionAt(cpos));
+						}
+						*out++ = static_cast<unsigned int>(v.first->second);
+					}
+				}
+				for (const auto i : {0U, 3U, 1U, 0U, 2U, 3U}) {
+					indices.push_back(currentIndices[i]);
+				}
+			});
+	meshes.create<MeshT<Vertex>>(vertices, indices);
+}
+
+void
+Water::tick(TickDuration dur)
+{
+	waveCycle += dur.count();
+}
+
+void
+Water::render(const SceneShader & shader) const
+{
+	shader.water.use(waveCycle);
+	water->bind();
+	meshes.apply(&MeshT<GlobalPosition3D>::Draw);
+}