Qt Quick 3D - 自定义几何图形范例
// Copyright (C) 2020 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "examplegeometry.h"
#include <QRandomGenerator>
#include <QVector3D>
ExampleTriangleGeometry::ExampleTriangleGeometry()
{
updateData();
}
void ExampleTriangleGeometry::setNormals(bool enable)
{
if (m_hasNormals == enable)
return;
m_hasNormals = enable;
emit normalsChanged();
updateData();
update();
}
void ExampleTriangleGeometry::setNormalXY(float xy)
{
if (m_normalXY == xy)
return;
m_normalXY = xy;
emit normalXYChanged();
updateData();
update();
}
void ExampleTriangleGeometry::setUV(bool enable)
{
if (m_hasUV == enable)
return;
m_hasUV = enable;
emit uvChanged();
updateData();
update();
}
void ExampleTriangleGeometry::setUVAdjust(float f)
{
if (m_uvAdjust == f)
return;
m_uvAdjust = f;
emit uvAdjustChanged();
updateData();
update();
}
void ExampleTriangleGeometry::updateData()
{
clear();
int stride = 3 * sizeof(float);
if (m_hasNormals)
stride += 3 * sizeof(float);
if (m_hasUV)
stride += 2 * sizeof(float);
QByteArray vertexData(3 * stride, Qt::Initialization::Uninitialized);
float *p = reinterpret_cast<float *>(vertexData.data());
// a triangle, front face = counter-clockwise
*p++ = -1.0f; *p++ = -1.0f; *p++ = 0.0f;
if (m_hasNormals) {
*p++ = m_normalXY; *p++ = m_normalXY; *p++ = 1.0f;
}
if (m_hasUV) {
*p++ = 0.0f + m_uvAdjust; *p++ = 0.0f + m_uvAdjust;
}
*p++ = 1.0f; *p++ = -1.0f; *p++ = 0.0f;
if (m_hasNormals) {
*p++ = m_normalXY; *p++ = m_normalXY; *p++ = 1.0f;
}
if (m_hasUV) {
*p++ = 1.0f - m_uvAdjust; *p++ = 0.0f + m_uvAdjust;
}
*p++ = 0.0f; *p++ = 1.0f; *p++ = 0.0f;
if (m_hasNormals) {
*p++ = m_normalXY; *p++ = m_normalXY; *p++ = 1.0f;
}
if (m_hasUV) {
*p++ = 1.0f - m_uvAdjust; *p++ = 1.0f - m_uvAdjust;
}
setVertexData(vertexData);
setStride(stride);
setBounds(QVector3D(-1.0f, -1.0f, 0.0f), QVector3D(+1.0f, +1.0f, 0.0f));
setPrimitiveType(QQuick3DGeometry::PrimitiveType::Triangles);
addAttribute(QQuick3DGeometry::Attribute::PositionSemantic,
0,
QQuick3DGeometry::Attribute::F32Type);
if (m_hasNormals) {
addAttribute(QQuick3DGeometry::Attribute::NormalSemantic,
3 * sizeof(float),
QQuick3DGeometry::Attribute::F32Type);
}
if (m_hasUV) {
addAttribute(QQuick3DGeometry::Attribute::TexCoordSemantic,
m_hasNormals ? 6 * sizeof(float) : 3 * sizeof(float),
QQuick3DGeometry::Attribute::F32Type);
}
}
ExamplePointGeometry::ExamplePointGeometry()
{
updateData();
}
void ExamplePointGeometry::updateData()
{
clear();
constexpr auto randomFloat = [](const float lowest, const float highest) -> float {
return lowest + QRandomGenerator::global()->generateDouble() * (highest - lowest);
};
constexpr int NUM_POINTS = 2000;
constexpr int stride = 3 * sizeof(float);
QByteArray vertexData;
vertexData.resize(NUM_POINTS * stride);
float *p = reinterpret_cast<float *>(vertexData.data());
for (int i = 0; i < NUM_POINTS; ++i) {
*p++ = randomFloat(-5.0f, +5.0f);
*p++ = randomFloat(-5.0f, +5.0f);
*p++ = 0.0f;
}
setVertexData(vertexData);
setStride(stride);
setBounds(QVector3D(-5.0f, -5.0f, 0.0f), QVector3D(+5.0f, +5.0f, 0.0f));
setPrimitiveType(QQuick3DGeometry::PrimitiveType::Points);
addAttribute(QQuick3DGeometry::Attribute::PositionSemantic,
0,
QQuick3DGeometry::Attribute::F32Type);
}