Files
UnrealEngine/Engine/Source/ThirdParty/MaterialX/MaterialX-1.38.10/source/MaterialXRender/Camera.cpp
2025-05-18 13:04:45 +08:00

126 lines
4.2 KiB
C++

//
// Copyright Contributors to the MaterialX Project
// SPDX-License-Identifier: Apache-2.0
//
#include <MaterialXRender/Camera.h>
MATERIALX_NAMESPACE_BEGIN
Matrix44 Camera::createViewMatrix(const Vector3& eye,
const Vector3& target,
const Vector3& up)
{
Vector3 z = (target - eye).getNormalized();
Vector3 x = z.cross(up).getNormalized();
Vector3 y = x.cross(z);
return Matrix44(
x[0], y[0], -z[0], 0.0f,
x[1], y[1], -z[1], 0.0f,
x[2], y[2], -z[2], 0.0f,
-x.dot(eye), -y.dot(eye), z.dot(eye), 1.0f);
}
Matrix44 Camera::createPerspectiveMatrixZP(float left, float right,
float bottom, float top,
float nearP, float farP)
{
return Matrix44(
(2.0f * nearP) / (right - left), 0.0f, (right + left) / (right - left), 0.0f,
0.0f, (2.0f * nearP) / (top - bottom), (top + bottom) / (top - bottom), 0.0f,
0.0f, 0.0f, -1 / (farP - nearP), -1.0f,
0.0f, 0.0f, -nearP / (farP - nearP), 0.0f);
}
Matrix44 Camera::createOrthographicMatrixZP(float left, float right,
float bottom, float top,
float nearP, float farP)
{
return Matrix44(
2.0f / (right - left), 0.0f, 0.0f, 0.0f,
0.0f, 2.0f / (top - bottom), 0.0f, 0.0f,
0.0f, 0.0f, -1.0f / (farP - nearP), 0.0f,
-(right + left) / (right - left), -(top + bottom) / (top - bottom), -nearP / (farP - nearP), 1.0f);
}
Matrix44 Camera::createPerspectiveMatrix(float left, float right,
float bottom, float top,
float nearP, float farP)
{
return Matrix44(
(2.0f * nearP) / (right - left), 0.0f, (right + left) / (right - left), 0.0f,
0.0f, (2.0f * nearP) / (top - bottom), (top + bottom) / (top - bottom), 0.0f,
0.0f, 0.0f, -(farP + nearP) / (farP - nearP), -1.0f,
0.0f, 0.0f, -(2.0f * farP * nearP) / (farP - nearP), 0.0f);
}
Matrix44 Camera::createOrthographicMatrix(float left, float right,
float bottom, float top,
float nearP, float farP)
{
return Matrix44(
2.0f / (right - left), 0.0f, 0.0f, 0.0f,
0.0f, 2.0f / (top - bottom), 0.0f, 0.0f,
0.0f, 0.0f, -2.0f / (farP - nearP), 0.0f,
-(right + left) / (right - left), -(top + bottom) / (top - bottom), -(farP + nearP) / (farP - nearP), 1.0f);
}
void Camera::arcballButtonEvent(const Vector2& pos, bool pressed)
{
_arcballActive = pressed;
_arcballLastPos = pos;
if (!_arcballActive)
{
_arcballQuat = (_arcballDelta * _arcballQuat).getNormalized();
}
_arcballDelta = Quaternion::IDENTITY;
}
bool Camera::applyArcballMotion(const Vector2& pos)
{
if (!_arcballActive)
{
return false;
}
float w = _viewportSize[0];
float h = _viewportSize[1];
float invMinDim = 1.0f / std::min(w, h);
float ox = (_arcballSpeed * (2.0f * _arcballLastPos[0] - w) + w) - w - 1.0f;
float tx = (_arcballSpeed * (2.0f * pos[0] - w) + w) - w - 1.0f;
float oy = (_arcballSpeed * (h - 2.0f * _arcballLastPos[1]) + h) - h - 1.0f;
float ty = (_arcballSpeed * (h - 2.0f * pos[1]) + h) - h - 1.0f;
ox *= invMinDim;
oy *= invMinDim;
tx *= invMinDim;
ty *= invMinDim;
Vector3 v0(ox, oy, 1.0f);
Vector3 v1(tx, ty, 1.0f);
if (v0.dot(v0) > 1e-4f && v1.dot(v1) > 1e-4f)
{
v0 = v0.getNormalized();
v1 = v1.getNormalized();
Vector3 axis = v0.cross(v1);
float sa = std::sqrt(axis.dot(axis));
float ca = v0.dot(v1);
float angle = std::atan2(sa, ca);
if (tx*tx + ty*ty > 1.0f)
{
angle *= 1.0f + 0.2f * (std::sqrt(tx*tx + ty*ty) - 1.0f);
}
axis = axis.getNormalized();
_arcballDelta = Quaternion::createFromAxisAngle(axis, angle);
if (!std::isfinite(_arcballDelta.getMagnitude()))
{
_arcballDelta = Quaternion::IDENTITY;
}
}
return true;
}
MATERIALX_NAMESPACE_END