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chore: change Mesh API
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@painfulexistence
painfulexistence committed Jun 21, 2024
1 parent c41cce6 commit ba5302e
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Showing 2 changed files with 54 additions and 44 deletions.
92 changes: 51 additions & 41 deletions AtmosphericEngine/mesh.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@ Mesh::~Mesh()
//delete collisionShape; // FIXME: Should delete collisionShape somewhere else before the pointer is out of scope
}

void Mesh::BufferData()
void Mesh::Initialize(const std::vector<GLfloat>& verts, const std::vector<GLushort>& tris)
{
// Buffer binding reference: https://stackoverflow.com/questions/17332657/does-a-vao-remember-both-a-ebo-ibo-elements-or-indices-and-a-vbo
glBindVertexArray(vao);
Expand Down Expand Up @@ -51,6 +51,8 @@ void Mesh::BufferData()

glBindVertexArray(0);

this->vertCount = verts.size() / 8;
this->triCount = tris.size() / 3;
this->_initialized = true;
}

Expand Down Expand Up @@ -84,7 +86,7 @@ void Mesh::Render(ShaderProgram& program, const std::vector<glm::mat4>& worldMat
glBindVertexArray(vao);
glBindBuffer(GL_ARRAY_BUFFER, ibo);
glBufferData(GL_ARRAY_BUFFER, worldMatrices.size() * sizeof(glm::mat4), worldMatrices.data(), GL_STATIC_DRAW);
glDrawElementsInstanced(primitiveType, tris.size(), GL_UNSIGNED_SHORT, 0, worldMatrices.size());
glDrawElementsInstanced(primitiveType, triCount * 3, GL_UNSIGNED_SHORT, 0, worldMatrices.size());
glBindVertexArray(0);
}

Expand Down Expand Up @@ -114,7 +116,6 @@ void Mesh::Render(ShaderProgram& program, const std::vector<glm::mat4>& worldMat

Mesh* Mesh::CreateCube(const GLfloat& size)
{
auto cube = new Mesh();
GLfloat vertices[] = {
//left
.5f * size, .5f * size, .5f * size, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f,
Expand Down Expand Up @@ -147,8 +148,6 @@ Mesh* Mesh::CreateCube(const GLfloat& size)
-.5f * size, -.5f * size, .5f * size, 0.0f, -1.0f, 0.0f, 0.0f, 1.0f,
-.5f * size, -.5f * size, -.5f * size, 0.0f, -1.0f, 0.0f, 0.0f, 0.0f
};
cube->verts.assign(vertices, vertices + 192);

GLushort triangles[] = {
0, 2, 1,
1, 2, 3,
Expand All @@ -163,8 +162,12 @@ Mesh* Mesh::CreateCube(const GLfloat& size)
20, 22, 21,
21, 22, 23
};
cube->tris.assign(triangles, triangles + 36);
cube->BufferData();

std::vector<GLfloat> verts(vertices, vertices + 192);
std::vector<GLushort> tris(triangles, triangles + 36);

auto cube = new Mesh();
cube->Initialize(verts, tris);

cube->bounds[0] = glm::vec3(.5f * size, .5f * size, .5f * size);
cube->bounds[1] = glm::vec3(-.5f * size, .5f * size, .5f * size);
Expand All @@ -180,10 +183,11 @@ Mesh* Mesh::CreateCube(const GLfloat& size)

Mesh* Mesh::CreateSphere(const GLfloat& radius, const GLint& division)
{
auto sphere = new Mesh();

float delta = (float)PI / (float)division;
sphere->verts.resize(8 * (division + 1) * (2 * division + 1));

std::vector<GLfloat> verts;
std::vector<GLushort> tris;
verts.resize(8 * (division + 1) * (2 * division + 1));
for (int v = 0; v <= division; ++v)
{
float vAngle = v * delta;
Expand Down Expand Up @@ -211,38 +215,40 @@ Mesh* Mesh::CreateSphere(const GLfloat& radius, const GLint& division)
);
norm = glm::normalize(pos);
}
sphere->verts[8 * (v * (2 * division + 1) + h)] = pos.x;
sphere->verts[8 * (v * (2 * division + 1) + h) + 1] = pos.y;
sphere->verts[8 * (v * (2 * division + 1) + h) + 2] = pos.z;
sphere->verts[8 * (v * (2 * division + 1) + h) + 3] = norm.x;
sphere->verts[8 * (v * (2 * division + 1) + h) + 4] = norm.y;
sphere->verts[8 * (v * (2 * division + 1) + h) + 5] = norm.z;
sphere->verts[8 * (v * (2 * division + 1) + h) + 6] = (float)h / (float)(2 * division);
sphere->verts[8 * (v * (2 * division + 1) + h) + 7] = 1.0f - (float)v / (float)division;
verts[8 * (v * (2 * division + 1) + h)] = pos.x;
verts[8 * (v * (2 * division + 1) + h) + 1] = pos.y;
verts[8 * (v * (2 * division + 1) + h) + 2] = pos.z;
verts[8 * (v * (2 * division + 1) + h) + 3] = norm.x;
verts[8 * (v * (2 * division + 1) + h) + 4] = norm.y;
verts[8 * (v * (2 * division + 1) + h) + 5] = norm.z;
verts[8 * (v * (2 * division + 1) + h) + 6] = (float)h / (float)(2 * division);
verts[8 * (v * (2 * division + 1) + h) + 7] = 1.0f - (float)v / (float)division;
}
}
sphere->tris.resize((6 * division - 6) * (2 * division));
tris.resize((6 * division - 6) * (2 * division));
for (int v = 0, i = 0; v <= division - 1; ++v)
{
for (int h = 0; h <= 2 * division - 1; ++h)
{
if (v != 0) //top-left triangles except for north pole
{
sphere->tris[i] = (2 * division + 1) * v + h;
sphere->tris[i + 1] = (2 * division + 1) * v + h + 1;
sphere->tris[i + 2] = (2 * division + 1) * (v + 1) + h;
tris[i] = (2 * division + 1) * v + h;
tris[i + 1] = (2 * division + 1) * v + h + 1;
tris[i + 2] = (2 * division + 1) * (v + 1) + h;
i += 3;
}
if (v != division - 1) //bottom-right triangles except for south pole
{
sphere->tris[i] = (2 * division + 1) * (v + 1) + h;
sphere->tris[i + 1] = (2 * division + 1) * v + h + 1;
sphere->tris[i + 2] = (2 * division + 1) * (v + 1) + h + 1;
tris[i] = (2 * division + 1) * (v + 1) + h;
tris[i + 1] = (2 * division + 1) * v + h + 1;
tris[i + 2] = (2 * division + 1) * (v + 1) + h + 1;
i += 3;
}
}
}
sphere->BufferData();

auto sphere = new Mesh();
sphere->Initialize(verts, tris);

sphere->bounds[0] = glm::vec3(radius, radius, radius);
sphere->bounds[1] = glm::vec3(-radius, radius, radius);
Expand All @@ -258,33 +264,37 @@ Mesh* Mesh::CreateSphere(const GLfloat& radius, const GLint& division)

Mesh* Mesh::CreateTerrain(const GLfloat& size, const GLint& vnum, const std::vector<GLfloat>& heightmap)
{
auto terrain = new Mesh();
terrain->verts.resize(vnum * vnum * 8);
std::vector<GLfloat> verts;
std::vector<GLushort> tris;

verts.resize(vnum * vnum * 8);
float c_size = size / float(vnum - 1);
for (int i = 0; i < vnum; i++) {
for (int j = 0; j < vnum; j++) {
float x = -.5f * size + j * c_size;
float y = heightmap[(i * vnum + j)];
float z = -.5f * size + i * c_size;
terrain->verts[(i * vnum + j) * 8 + 0] = x;
terrain->verts[(i * vnum + j) * 8 + 1] = y;
terrain->verts[(i * vnum + j) * 8 + 2] = z;
terrain->verts[(i * vnum + j) * 8 + 3] = 0.f; //2 * float(i)/float(vnum);
terrain->verts[(i * vnum + j) * 8 + 4] = 1.f; //2 * float(j)/float(vnum);
terrain->verts[(i * vnum + j) * 8 + 5] = 0.f; //0.8f;
terrain->verts[(i * vnum + j) * 8 + 6] = (float)(i%2);
terrain->verts[(i * vnum + j) * 8 + 7] = (float)(j%2);
verts[(i * vnum + j) * 8 + 0] = x;
verts[(i * vnum + j) * 8 + 1] = y;
verts[(i * vnum + j) * 8 + 2] = z;
verts[(i * vnum + j) * 8 + 3] = 0.f; //2 * float(i)/float(vnum);
verts[(i * vnum + j) * 8 + 4] = 1.f; //2 * float(j)/float(vnum);
verts[(i * vnum + j) * 8 + 5] = 0.f; //0.8f;
verts[(i * vnum + j) * 8 + 6] = (float)(i%2);
verts[(i * vnum + j) * 8 + 7] = (float)(j%2);
}
}
terrain->tris.resize((vnum * 2 + 1) * (vnum - 1));
terrain->primitiveType = GL_TRIANGLE_STRIP;
tris.resize((vnum * 2 + 1) * (vnum - 1));
for (int i = 0; i < vnum - 1; i++) {
for (int j = 0; j < 2 * vnum; j++) {
terrain->tris[i * (2 * vnum + 1) + j] = (i + j % 2) * vnum + (j / 2);
tris[i * (2 * vnum + 1) + j] = (i + j % 2) * vnum + (j / 2);
}
terrain->tris[i * (2 * vnum + 1) + 2 * vnum] = 0xFFFF;
tris[i * (2 * vnum + 1) + 2 * vnum] = 0xFFFF;
}
terrain->BufferData();

auto terrain = new Mesh();
terrain->Initialize(verts, tris);
terrain->primitiveType = GL_TRIANGLE_STRIP;

terrain->bounds[0] = glm::vec3(.5f * size, .5f, .5f * size);
terrain->bounds[1] = glm::vec3(-.5f * size, .5f, .5f * size);
Expand Down
6 changes: 3 additions & 3 deletions AtmosphericEngine/mesh.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -8,8 +8,8 @@ class Mesh
{
private:
GLuint vao, vbo, ebo, ibo;
std::vector<GLfloat> verts;
std::vector<GLushort> tris;
size_t vertCount;
size_t triCount;
std::array<glm::vec3, 8> bounds;
bool _initialized = false;

Expand All @@ -26,7 +26,7 @@ class Mesh

~Mesh();

void BufferData();
void Initialize(const std::vector<GLfloat>& verts, const std::vector<GLushort>& tris);

std::array<glm::vec3, 8> GetBoundingBox() const { return bounds; }

Expand Down

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