#include "roundedbox.h"
VertexDescription P3T2N3Vertex::description[] = {
{VertexDescription::Position, GL_FLOAT, SIZE_OF_MEMBER(P3T2N3Vertex, position) / sizeof(float), 0, 0},
{VertexDescription::TexCoord, GL_FLOAT, SIZE_OF_MEMBER(P3T2N3Vertex, texCoord) / sizeof(float), sizeof(QVector3D), 0},
{VertexDescription::Normal, GL_FLOAT, SIZE_OF_MEMBER(P3T2N3Vertex, normal) / sizeof(float), sizeof(QVector3D) + sizeof(QVector2D), 0},
{VertexDescription::Null, 0, 0, 0, 0},
};
float lerp(float a, float b, float t)
{
return a * (1.0f - t) + b * t;
}
GLRoundedBox::GLRoundedBox(float r, float scale, int n)
: GLTriangleMesh<P3T2N3Vertex, unsigned short>((n+2)*(n+3)*4, (n+1)*(n+1)*24+36+72*(n+1))
{
int vidx = 0, iidx = 0;
int vertexCountPerCorner = (n + 2) * (n + 3) / 2;
P3T2N3Vertex *vp = m_vb.lock();
unsigned short *ip = m_ib.lock();
if (!vp || !ip) {
qWarning("GLRoundedBox::GLRoundedBox: Failed to lock vertex buffer and/or index buffer.");
m_ib.unlock();
m_vb.unlock();
return;
}
for (int corner = 0; corner < 8; ++corner) {
QVector3D centre(corner & 1 ? 1.0f : -1.0f,
corner & 2 ? 1.0f : -1.0f,
corner & 4 ? 1.0f : -1.0f);
int winding = (corner & 1) ^ ((corner >> 1) & 1) ^ (corner >> 2);
int offsX = ((corner ^ 1) - corner) * vertexCountPerCorner;
int offsY = ((corner ^ 2) - corner) * vertexCountPerCorner;
int offsZ = ((corner ^ 4) - corner) * vertexCountPerCorner;
if (winding) {
ip[iidx++] = vidx;
ip[iidx++] = vidx + offsX;
ip[iidx++] = vidx + offsY;
ip[iidx++] = vidx + vertexCountPerCorner - n - 2;
ip[iidx++] = vidx + vertexCountPerCorner - n - 2 + offsY;
ip[iidx++] = vidx + vertexCountPerCorner - n - 2 + offsZ;
ip[iidx++] = vidx + vertexCountPerCorner - 1;
ip[iidx++] = vidx + vertexCountPerCorner - 1 + offsZ;
ip[iidx++] = vidx + vertexCountPerCorner - 1 + offsX;
}
for (int i = 0; i < n + 2; ++i) {
if (winding && i < n + 1) {
ip[iidx++] = vidx + i + 1;
ip[iidx++] = vidx;
ip[iidx++] = vidx + offsY + i + 1;
ip[iidx++] = vidx + offsY;
ip[iidx++] = vidx + offsY + i + 1;
ip[iidx++] = vidx;
ip[iidx++] = vidx + i;
ip[iidx++] = vidx + 2 * i + 2;
ip[iidx++] = vidx + i + offsX;
ip[iidx++] = vidx + 2 * i + offsX + 2;
ip[iidx++] = vidx + i + offsX;
ip[iidx++] = vidx + 2 * i + 2;
ip[iidx++] = (corner + 1) * vertexCountPerCorner - 1 - i;
ip[iidx++] = (corner + 1) * vertexCountPerCorner - 2 - i;
ip[iidx++] = (corner + 1) * vertexCountPerCorner - 1 - i + offsZ;
ip[iidx++] = (corner + 1) * vertexCountPerCorner - 2 - i + offsZ;
ip[iidx++] = (corner + 1) * vertexCountPerCorner - 1 - i + offsZ;
ip[iidx++] = (corner + 1) * vertexCountPerCorner - 2 - i;
}
for (int j = 0; j <= i; ++j) {
QVector3D normal = QVector3D(i - j, j, n + 1 - i).normalized();
QVector3D offset(0.5f - r, 0.5f - r, 0.5f - r);
QVector3D pos = centre * (offset + r * normal);
vp[vidx].position = scale * pos;
vp[vidx].normal = centre * normal;
vp[vidx].texCoord = QVector2D(pos.x() + 0.5f, pos.y() + 0.5f);
if (i < n + 1) {
ip[iidx++] = vidx;
ip[iidx++] = vidx + i + 2 - winding;
ip[iidx++] = vidx + i + 1 + winding;
}
if (i < n) {
ip[iidx++] = vidx + i + 1 + winding;
ip[iidx++] = vidx + i + 2 - winding;
ip[iidx++] = vidx + 2 * i + 4;
}
++vidx;
}
}
}
m_ib.unlock();
m_vb.unlock();
}