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#include "terrain.h"
#include "gfx/models/texture.h"
#include <array>
#include <cache.h>
#include <cstddef>
#include <gfx/gl/shader.h>
#include <gfx/gl/transform.h>
#include <gfx/models/vertex.hpp>
#include <glm/glm.hpp>
constexpr auto size {255}; // Vertices
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
Terrain::Terrain() :
m_vertexArrayObject {}, m_vertexArrayBuffers {}, texture {Texture::cachedTexture.get("res/bricks.jpg")}
{
vertices.resize(verticesCount, {{}, {}, {}});
indices.reserve(indicesCount);
// Initial coordinates
for (auto z = 0; z < size; z += 1) {
for (auto x = 0; x < size; x += 1) {
auto & vertex = vertices[x + (z * size)];
vertex.pos = {resolution * x, -1, resolution * z};
vertex.normal = {0, 1, 0};
vertex.texCoord = {x % 2, z % 2};
}
}
// 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));
}
}
glGenVertexArrays(1, &m_vertexArrayObject);
glBindVertexArray(m_vertexArrayObject);
glGenBuffers(2, m_vertexArrayBuffers.data());
glBindBuffer(GL_ARRAY_BUFFER, m_vertexArrayBuffers[0]);
glBufferData(GL_ARRAY_BUFFER, sizeof(Vertex) * vertices.size(), vertices.data(), GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void *)offsetof(Vertex, pos));
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void *)offsetof(Vertex, texCoord));
glEnableVertexAttribArray(2);
glVertexAttribPointer(2, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void *)offsetof(Vertex, normal));
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_vertexArrayBuffers[1]);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices[0]) * indices.size(), indices.data(), GL_STATIC_DRAW);
glBindVertexArray(0);
}
Terrain::~Terrain()
{
glDeleteBuffers(NUM_BUFFERS, m_vertexArrayBuffers.data());
glDeleteVertexArrays(1, &m_vertexArrayObject);
}
static const Transform identity {};
static const auto identityModel {identity.GetModel()};
void
Terrain::render(const Shader & shader) const
{
shader.setModel(identityModel);
texture->Bind();
glBindVertexArray(m_vertexArrayObject);
glDrawElementsBaseVertex(GL_TRIANGLES, indices.size(), GL_UNSIGNED_INT, nullptr, 0);
glBindVertexArray(0);
}
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