From 69a3b65fd17149d2c984188953c0749437e0744b Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Thu, 28 Jan 2021 19:48:19 +0000
Subject: Split common terrain code out
---
game/terrain.cpp | 76 +++++++++++++++++++++++++++++++-------------------------
game/terrain.h | 4 ++-
2 files changed, 45 insertions(+), 35 deletions(-)
(limited to 'game')
diff --git a/game/terrain.cpp b/game/terrain.cpp
index 27fdc1c..fc98f08 100644
--- a/game/terrain.cpp
+++ b/game/terrain.cpp
@@ -10,24 +10,19 @@
#include <glm/glm.hpp>
#include <random>
-constexpr auto size {241}; // Vertices
-constexpr auto offset {(size - 1) / 2};
-constexpr auto verticesCount = size * size;
-constexpr auto tilesCount = (size - 1) * (size - 1);
-constexpr auto trianglesCount = tilesCount * 2;
-constexpr auto indicesCount = trianglesCount * 3;
-constexpr auto resolution = 10; // Grid size
-constexpr auto extent = offset * resolution;
-
Terrain::Terrain() :
m_vertexArrayObject {}, m_vertexArrayBuffers {}, texture {Texture::cachedTexture.get("res/terrain.png")}
{
+ constexpr auto size {241}; // Vertices
+ constexpr auto offset {(size - 1) / 2};
+ constexpr auto verticesCount = size * size;
+ constexpr auto resolution = 10; // Grid size
+
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
vertices.reserve(verticesCount + 4);
vertices.resize(verticesCount, {{}, {}, {}});
- indices.reserve(indicesCount + 6);
// Initial coordinates
for (auto z = 0; z < size; z += 1) {
@@ -38,17 +33,6 @@ Terrain::Terrain() :
vertex.texCoord = {(x % 2) / 2.01, (z % 2) / 2.01};
}
}
- // Indices
- for (auto z = 0; z < size - 1; z += 1) {
- for (auto x = 0; x < size - 1; x += 1) {
- indices.push_back(x + (z * size));
- indices.push_back((x + 1) + ((z + 1) * size));
- indices.push_back((x + 1) + (z * size));
- indices.push_back(x + (z * size));
- indices.push_back(x + ((z + 1) * size));
- indices.push_back((x + 1) + ((z + 1) * size));
- }
- }
// Add hills
std::mt19937 gen(std::random_device {}());
std::uniform_int_distribution<> rpos(2, size - 2);
@@ -75,21 +59,45 @@ Terrain::Terrain() :
}
}
}
+ finish(size, size, resolution);
+}
+
+void
+Terrain::finish(unsigned int width, unsigned int height, unsigned int resolution)
+{
+ const auto tilesCount = (width - 1) * (height - 1);
+ const auto trianglesCount = tilesCount * 2;
+ const auto indicesCount = trianglesCount * 3;
+ indices.reserve(indicesCount + 6);
+ // Indices
+ for (auto z = 0U; z < height - 1; z += 1) {
+ for (auto x = 0U; x < width - 1; x += 1) {
+ indices.push_back(x + (z * width));
+ indices.push_back((x + 1) + ((z + 1) * width));
+ indices.push_back((x + 1) + (z * width));
+ indices.push_back(x + (z * width));
+ indices.push_back(x + ((z + 1) * width));
+ indices.push_back((x + 1) + ((z + 1) * width));
+ }
+ }
// Normals
- for (auto z = 1; z < size - 1; z += 1) {
- for (auto x = 1; x < size - 1; x += 1) {
- const auto a = v(x - 1, z).pos;
- const auto b = v(x, z - 1).pos;
- const auto c = v(x + 1, z).pos;
- const auto d = v(x, z + 1).pos;
- v(x, z).normal = -glm::normalize(glm::cross(c - a, d - b));
+ for (auto z = 1U; z < height - 1; z += 1) {
+ for (auto x = 1U; x < width - 1; x += 1) {
+ const auto a = v(width, x - 1, z).pos;
+ const auto b = v(width, x, z - 1).pos;
+ const auto c = v(width, x + 1, z).pos;
+ const auto d = v(width, x, z + 1).pos;
+ v(width, x, z).normal = -glm::normalize(glm::cross(c - a, d - b));
}
}
+ const auto verticesCount = vertices.size();
// Add water
- vertices.emplace_back(glm::vec3 {-extent, 0, -extent}, glm::vec2 {0.5, 0.0}, glm::vec3 {0, 1, 0});
- vertices.emplace_back(glm::vec3 {-extent, 0, extent}, glm::vec2 {0.5, 0.5}, glm::vec3 {0, 1, 0});
- vertices.emplace_back(glm::vec3 {extent, 0, extent}, glm::vec2 {1, 0.5}, glm::vec3 {0, 1, 0});
- vertices.emplace_back(glm::vec3 {extent, 0, -extent}, glm::vec2 {1, 0.0}, glm::vec3 {0, 1, 0});
+ const auto extentx {(int)((width - 1) * resolution / 2)};
+ const auto extentz {(int)((height - 1) * resolution / 2)};
+ vertices.emplace_back(glm::vec3 {-extentx, 0, -extentz}, glm::vec2 {0.5, 0.0}, glm::vec3 {0, 1, 0});
+ vertices.emplace_back(glm::vec3 {-extentx, 0, extentz}, glm::vec2 {0.5, 0.5}, glm::vec3 {0, 1, 0});
+ vertices.emplace_back(glm::vec3 {extentx, 0, extentz}, glm::vec2 {1, 0.5}, glm::vec3 {0, 1, 0});
+ vertices.emplace_back(glm::vec3 {extentx, 0, -extentz}, glm::vec2 {1, 0.0}, glm::vec3 {0, 1, 0});
indices.push_back(verticesCount);
indices.push_back(verticesCount + 1);
indices.push_back(verticesCount + 2);
@@ -121,9 +129,9 @@ Terrain::Terrain() :
}
Vertex &
-Terrain::v(unsigned int x, unsigned int z)
+Terrain::v(unsigned int width, unsigned int x, unsigned int z)
{
- return vertices[x + (z * size)];
+ return vertices[x + (z * width)];
}
Terrain::~Terrain()
diff --git a/game/terrain.h b/game/terrain.h
index c039730..0edf4bd 100644
--- a/game/terrain.h
+++ b/game/terrain.h
@@ -27,7 +27,9 @@ public:
private:
static constexpr unsigned int NUM_BUFFERS {4};
- Vertex & v(unsigned int, unsigned int);
+ void finish(unsigned int width, unsigned int height, unsigned int resolution);
+
+ Vertex & v(unsigned int width, unsigned int x, unsigned int z);
GLuint m_vertexArrayObject;
std::array<GLuint, NUM_BUFFERS> m_vertexArrayBuffers;
--
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