godot/core/math/camera_matrix.cpp
lawnjelly eaf8e5ce52 Change CameraMatrix::get_viewport_size to get_viewport_half_extents
Fixes #26637.
Fixes #19900.

The viewport_size returned by get_viewport_size was previously incorrect, being half the correct value. The function is renamed to get_viewport_half_extents, and now returns a Vector2.

Code which called this function has also been modified accordingly.

This PR also fixes shadow culling when using ortho cameras, because the correct input for CameraMatrix::set_orthogonal should be the full HEIGHT from get_viewport_half_extents, and not half the width.

It also fixes state.ubo_data.viewport_size in rasterizer_scene_gles3.cpp to be the width and the height of the viewport in pixels as stated in the documentation, rather than the current value which is half the viewport extents in worldspace, presumed to be a bug.
2020-01-22 18:22:00 +00:00

686 lines
19 KiB
C++

/*************************************************************************/
/* camera_matrix.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
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/*************************************************************************/
#include "camera_matrix.h"
#include "core/math/math_funcs.h"
#include "core/print_string.h"
void CameraMatrix::set_identity() {
for (int i = 0; i < 4; i++) {
for (int j = 0; j < 4; j++) {
matrix[i][j] = (i == j) ? 1 : 0;
}
}
}
void CameraMatrix::set_zero() {
for (int i = 0; i < 4; i++) {
for (int j = 0; j < 4; j++) {
matrix[i][j] = 0;
}
}
}
Plane CameraMatrix::xform4(const Plane &p_vec4) const {
Plane ret;
ret.normal.x = matrix[0][0] * p_vec4.normal.x + matrix[1][0] * p_vec4.normal.y + matrix[2][0] * p_vec4.normal.z + matrix[3][0] * p_vec4.d;
ret.normal.y = matrix[0][1] * p_vec4.normal.x + matrix[1][1] * p_vec4.normal.y + matrix[2][1] * p_vec4.normal.z + matrix[3][1] * p_vec4.d;
ret.normal.z = matrix[0][2] * p_vec4.normal.x + matrix[1][2] * p_vec4.normal.y + matrix[2][2] * p_vec4.normal.z + matrix[3][2] * p_vec4.d;
ret.d = matrix[0][3] * p_vec4.normal.x + matrix[1][3] * p_vec4.normal.y + matrix[2][3] * p_vec4.normal.z + matrix[3][3] * p_vec4.d;
return ret;
}
void CameraMatrix::set_perspective(real_t p_fovy_degrees, real_t p_aspect, real_t p_z_near, real_t p_z_far, bool p_flip_fov) {
if (p_flip_fov) {
p_fovy_degrees = get_fovy(p_fovy_degrees, 1.0 / p_aspect);
}
real_t sine, cotangent, deltaZ;
real_t radians = p_fovy_degrees / 2.0 * Math_PI / 180.0;
deltaZ = p_z_far - p_z_near;
sine = Math::sin(radians);
if ((deltaZ == 0) || (sine == 0) || (p_aspect == 0)) {
return;
}
cotangent = Math::cos(radians) / sine;
set_identity();
matrix[0][0] = cotangent / p_aspect;
matrix[1][1] = cotangent;
matrix[2][2] = -(p_z_far + p_z_near) / deltaZ;
matrix[2][3] = -1;
matrix[3][2] = -2 * p_z_near * p_z_far / deltaZ;
matrix[3][3] = 0;
}
void CameraMatrix::set_perspective(real_t p_fovy_degrees, real_t p_aspect, real_t p_z_near, real_t p_z_far, bool p_flip_fov, int p_eye, real_t p_intraocular_dist, real_t p_convergence_dist) {
if (p_flip_fov) {
p_fovy_degrees = get_fovy(p_fovy_degrees, 1.0 / p_aspect);
}
real_t left, right, modeltranslation, ymax, xmax, frustumshift;
ymax = p_z_near * tan(p_fovy_degrees * Math_PI / 360.0f);
xmax = ymax * p_aspect;
frustumshift = (p_intraocular_dist / 2.0) * p_z_near / p_convergence_dist;
switch (p_eye) {
case 1: { // left eye
left = -xmax + frustumshift;
right = xmax + frustumshift;
modeltranslation = p_intraocular_dist / 2.0;
}; break;
case 2: { // right eye
left = -xmax - frustumshift;
right = xmax - frustumshift;
modeltranslation = -p_intraocular_dist / 2.0;
}; break;
default: { // mono, should give the same result as set_perspective(p_fovy_degrees,p_aspect,p_z_near,p_z_far,p_flip_fov)
left = -xmax;
right = xmax;
modeltranslation = 0.0;
}; break;
};
set_frustum(left, right, -ymax, ymax, p_z_near, p_z_far);
// translate matrix by (modeltranslation, 0.0, 0.0)
CameraMatrix cm;
cm.set_identity();
cm.matrix[3][0] = modeltranslation;
*this = *this * cm;
}
void CameraMatrix::set_for_hmd(int p_eye, real_t p_aspect, real_t p_intraocular_dist, real_t p_display_width, real_t p_display_to_lens, real_t p_oversample, real_t p_z_near, real_t p_z_far) {
// we first calculate our base frustum on our values without taking our lens magnification into account.
real_t f1 = (p_intraocular_dist * 0.5) / p_display_to_lens;
real_t f2 = ((p_display_width - p_intraocular_dist) * 0.5) / p_display_to_lens;
real_t f3 = (p_display_width / 4.0) / p_display_to_lens;
// now we apply our oversample factor to increase our FOV. how much we oversample is always a balance we strike between performance and how much
// we're willing to sacrifice in FOV.
real_t add = ((f1 + f2) * (p_oversample - 1.0)) / 2.0;
f1 += add;
f2 += add;
f3 *= p_oversample;
// always apply KEEP_WIDTH aspect ratio
f3 *= p_aspect;
switch (p_eye) {
case 1: { // left eye
set_frustum(-f2 * p_z_near, f1 * p_z_near, -f3 * p_z_near, f3 * p_z_near, p_z_near, p_z_far);
}; break;
case 2: { // right eye
set_frustum(-f1 * p_z_near, f2 * p_z_near, -f3 * p_z_near, f3 * p_z_near, p_z_near, p_z_far);
}; break;
default: { // mono, does not apply here!
}; break;
};
};
void CameraMatrix::set_orthogonal(real_t p_left, real_t p_right, real_t p_bottom, real_t p_top, real_t p_znear, real_t p_zfar) {
set_identity();
matrix[0][0] = 2.0 / (p_right - p_left);
matrix[3][0] = -((p_right + p_left) / (p_right - p_left));
matrix[1][1] = 2.0 / (p_top - p_bottom);
matrix[3][1] = -((p_top + p_bottom) / (p_top - p_bottom));
matrix[2][2] = -2.0 / (p_zfar - p_znear);
matrix[3][2] = -((p_zfar + p_znear) / (p_zfar - p_znear));
matrix[3][3] = 1.0;
}
void CameraMatrix::set_orthogonal(real_t p_size, real_t p_aspect, real_t p_znear, real_t p_zfar, bool p_flip_fov) {
if (!p_flip_fov) {
p_size *= p_aspect;
}
set_orthogonal(-p_size / 2, +p_size / 2, -p_size / p_aspect / 2, +p_size / p_aspect / 2, p_znear, p_zfar);
}
void CameraMatrix::set_frustum(real_t p_left, real_t p_right, real_t p_bottom, real_t p_top, real_t p_near, real_t p_far) {
ERR_FAIL_COND(p_right <= p_left);
ERR_FAIL_COND(p_top <= p_bottom);
ERR_FAIL_COND(p_far <= p_near);
real_t *te = &matrix[0][0];
real_t x = 2 * p_near / (p_right - p_left);
real_t y = 2 * p_near / (p_top - p_bottom);
real_t a = (p_right + p_left) / (p_right - p_left);
real_t b = (p_top + p_bottom) / (p_top - p_bottom);
real_t c = -(p_far + p_near) / (p_far - p_near);
real_t d = -2 * p_far * p_near / (p_far - p_near);
te[0] = x;
te[1] = 0;
te[2] = 0;
te[3] = 0;
te[4] = 0;
te[5] = y;
te[6] = 0;
te[7] = 0;
te[8] = a;
te[9] = b;
te[10] = c;
te[11] = -1;
te[12] = 0;
te[13] = 0;
te[14] = d;
te[15] = 0;
}
void CameraMatrix::set_frustum(real_t p_size, real_t p_aspect, Vector2 p_offset, real_t p_near, real_t p_far, bool p_flip_fov) {
if (!p_flip_fov) {
p_size *= p_aspect;
}
set_frustum(-p_size / 2 + p_offset.x, +p_size / 2 + p_offset.x, -p_size / p_aspect / 2 + p_offset.y, +p_size / p_aspect / 2 + p_offset.y, p_near, p_far);
}
real_t CameraMatrix::get_z_far() const {
const real_t *matrix = (const real_t *)this->matrix;
Plane new_plane = Plane(matrix[3] - matrix[2],
matrix[7] - matrix[6],
matrix[11] - matrix[10],
matrix[15] - matrix[14]);
new_plane.normal = -new_plane.normal;
new_plane.normalize();
return new_plane.d;
}
real_t CameraMatrix::get_z_near() const {
const real_t *matrix = (const real_t *)this->matrix;
Plane new_plane = Plane(matrix[3] + matrix[2],
matrix[7] + matrix[6],
matrix[11] + matrix[10],
-matrix[15] - matrix[14]);
new_plane.normalize();
return new_plane.d;
}
Vector2 CameraMatrix::get_viewport_half_extents() const {
const real_t *matrix = (const real_t *)this->matrix;
///////--- Near Plane ---///////
Plane near_plane = Plane(matrix[3] + matrix[2],
matrix[7] + matrix[6],
matrix[11] + matrix[10],
-matrix[15] - matrix[14]);
near_plane.normalize();
///////--- Right Plane ---///////
Plane right_plane = Plane(matrix[3] - matrix[0],
matrix[7] - matrix[4],
matrix[11] - matrix[8],
-matrix[15] + matrix[12]);
right_plane.normalize();
Plane top_plane = Plane(matrix[3] - matrix[1],
matrix[7] - matrix[5],
matrix[11] - matrix[9],
-matrix[15] + matrix[13]);
top_plane.normalize();
Vector3 res;
near_plane.intersect_3(right_plane, top_plane, &res);
return Vector2(res.x, res.y);
}
bool CameraMatrix::get_endpoints(const Transform &p_transform, Vector3 *p_8points) const {
Vector<Plane> planes = get_projection_planes(Transform());
const Planes intersections[8][3] = {
{ PLANE_FAR, PLANE_LEFT, PLANE_TOP },
{ PLANE_FAR, PLANE_LEFT, PLANE_BOTTOM },
{ PLANE_FAR, PLANE_RIGHT, PLANE_TOP },
{ PLANE_FAR, PLANE_RIGHT, PLANE_BOTTOM },
{ PLANE_NEAR, PLANE_LEFT, PLANE_TOP },
{ PLANE_NEAR, PLANE_LEFT, PLANE_BOTTOM },
{ PLANE_NEAR, PLANE_RIGHT, PLANE_TOP },
{ PLANE_NEAR, PLANE_RIGHT, PLANE_BOTTOM },
};
for (int i = 0; i < 8; i++) {
Vector3 point;
bool res = planes[intersections[i][0]].intersect_3(planes[intersections[i][1]], planes[intersections[i][2]], &point);
ERR_FAIL_COND_V(!res, false);
p_8points[i] = p_transform.xform(point);
}
return true;
}
Vector<Plane> CameraMatrix::get_projection_planes(const Transform &p_transform) const {
/** Fast Plane Extraction from combined modelview/projection matrices.
* References:
* https://web.archive.org/web/20011221205252/http://www.markmorley.com/opengl/frustumculling.html
* https://web.archive.org/web/20061020020112/http://www2.ravensoft.com/users/ggribb/plane%20extraction.pdf
*/
Vector<Plane> planes;
const real_t *matrix = (const real_t *)this->matrix;
Plane new_plane;
///////--- Near Plane ---///////
new_plane = Plane(matrix[3] + matrix[2],
matrix[7] + matrix[6],
matrix[11] + matrix[10],
matrix[15] + matrix[14]);
new_plane.normal = -new_plane.normal;
new_plane.normalize();
planes.push_back(p_transform.xform(new_plane));
///////--- Far Plane ---///////
new_plane = Plane(matrix[3] - matrix[2],
matrix[7] - matrix[6],
matrix[11] - matrix[10],
matrix[15] - matrix[14]);
new_plane.normal = -new_plane.normal;
new_plane.normalize();
planes.push_back(p_transform.xform(new_plane));
///////--- Left Plane ---///////
new_plane = Plane(matrix[3] + matrix[0],
matrix[7] + matrix[4],
matrix[11] + matrix[8],
matrix[15] + matrix[12]);
new_plane.normal = -new_plane.normal;
new_plane.normalize();
planes.push_back(p_transform.xform(new_plane));
///////--- Top Plane ---///////
new_plane = Plane(matrix[3] - matrix[1],
matrix[7] - matrix[5],
matrix[11] - matrix[9],
matrix[15] - matrix[13]);
new_plane.normal = -new_plane.normal;
new_plane.normalize();
planes.push_back(p_transform.xform(new_plane));
///////--- Right Plane ---///////
new_plane = Plane(matrix[3] - matrix[0],
matrix[7] - matrix[4],
matrix[11] - matrix[8],
matrix[15] - matrix[12]);
new_plane.normal = -new_plane.normal;
new_plane.normalize();
planes.push_back(p_transform.xform(new_plane));
///////--- Bottom Plane ---///////
new_plane = Plane(matrix[3] + matrix[1],
matrix[7] + matrix[5],
matrix[11] + matrix[9],
matrix[15] + matrix[13]);
new_plane.normal = -new_plane.normal;
new_plane.normalize();
planes.push_back(p_transform.xform(new_plane));
return planes;
}
CameraMatrix CameraMatrix::inverse() const {
CameraMatrix cm = *this;
cm.invert();
return cm;
}
void CameraMatrix::invert() {
int i, j, k;
int pvt_i[4], pvt_j[4]; /* Locations of pivot matrix */
real_t pvt_val; /* Value of current pivot element */
real_t hold; /* Temporary storage */
real_t determinat; /* Determinant */
determinat = 1.0;
for (k = 0; k < 4; k++) {
/** Locate k'th pivot element **/
pvt_val = matrix[k][k]; /** Initialize for search **/
pvt_i[k] = k;
pvt_j[k] = k;
for (i = k; i < 4; i++) {
for (j = k; j < 4; j++) {
if (Math::absd(matrix[i][j]) > Math::absd(pvt_val)) {
pvt_i[k] = i;
pvt_j[k] = j;
pvt_val = matrix[i][j];
}
}
}
/** Product of pivots, gives determinant when finished **/
determinat *= pvt_val;
if (Math::absd(determinat) < 1e-7) {
return; //(false); /** Matrix is singular (zero determinant). **/
}
/** "Interchange" rows (with sign change stuff) **/
i = pvt_i[k];
if (i != k) { /** If rows are different **/
for (j = 0; j < 4; j++) {
hold = -matrix[k][j];
matrix[k][j] = matrix[i][j];
matrix[i][j] = hold;
}
}
/** "Interchange" columns **/
j = pvt_j[k];
if (j != k) { /** If columns are different **/
for (i = 0; i < 4; i++) {
hold = -matrix[i][k];
matrix[i][k] = matrix[i][j];
matrix[i][j] = hold;
}
}
/** Divide column by minus pivot value **/
for (i = 0; i < 4; i++) {
if (i != k) matrix[i][k] /= (-pvt_val);
}
/** Reduce the matrix **/
for (i = 0; i < 4; i++) {
hold = matrix[i][k];
for (j = 0; j < 4; j++) {
if (i != k && j != k) matrix[i][j] += hold * matrix[k][j];
}
}
/** Divide row by pivot **/
for (j = 0; j < 4; j++) {
if (j != k) matrix[k][j] /= pvt_val;
}
/** Replace pivot by reciprocal (at last we can touch it). **/
matrix[k][k] = 1.0 / pvt_val;
}
/* That was most of the work, one final pass of row/column interchange */
/* to finish */
for (k = 4 - 2; k >= 0; k--) { /* Don't need to work with 1 by 1 corner*/
i = pvt_j[k]; /* Rows to swap correspond to pivot COLUMN */
if (i != k) { /* If rows are different */
for (j = 0; j < 4; j++) {
hold = matrix[k][j];
matrix[k][j] = -matrix[i][j];
matrix[i][j] = hold;
}
}
j = pvt_i[k]; /* Columns to swap correspond to pivot ROW */
if (j != k) /* If columns are different */
for (i = 0; i < 4; i++) {
hold = matrix[i][k];
matrix[i][k] = -matrix[i][j];
matrix[i][j] = hold;
}
}
}
CameraMatrix::CameraMatrix() {
set_identity();
}
CameraMatrix CameraMatrix::operator*(const CameraMatrix &p_matrix) const {
CameraMatrix new_matrix;
for (int j = 0; j < 4; j++) {
for (int i = 0; i < 4; i++) {
real_t ab = 0;
for (int k = 0; k < 4; k++)
ab += matrix[k][i] * p_matrix.matrix[j][k];
new_matrix.matrix[j][i] = ab;
}
}
return new_matrix;
}
void CameraMatrix::set_light_bias() {
real_t *m = &matrix[0][0];
m[0] = 0.5;
m[1] = 0.0;
m[2] = 0.0;
m[3] = 0.0;
m[4] = 0.0;
m[5] = 0.5;
m[6] = 0.0;
m[7] = 0.0;
m[8] = 0.0;
m[9] = 0.0;
m[10] = 0.5;
m[11] = 0.0;
m[12] = 0.5;
m[13] = 0.5;
m[14] = 0.5;
m[15] = 1.0;
}
void CameraMatrix::set_light_atlas_rect(const Rect2 &p_rect) {
real_t *m = &matrix[0][0];
m[0] = p_rect.size.width;
m[1] = 0.0;
m[2] = 0.0;
m[3] = 0.0;
m[4] = 0.0;
m[5] = p_rect.size.height;
m[6] = 0.0;
m[7] = 0.0;
m[8] = 0.0;
m[9] = 0.0;
m[10] = 1.0;
m[11] = 0.0;
m[12] = p_rect.position.x;
m[13] = p_rect.position.y;
m[14] = 0.0;
m[15] = 1.0;
}
CameraMatrix::operator String() const {
String str;
for (int i = 0; i < 4; i++)
for (int j = 0; j < 4; j++)
str += String((j > 0) ? ", " : "\n") + rtos(matrix[i][j]);
return str;
}
real_t CameraMatrix::get_aspect() const {
Vector2 vp_he = get_viewport_half_extents();
return vp_he.x / vp_he.y;
}
int CameraMatrix::get_pixels_per_meter(int p_for_pixel_width) const {
Vector3 result = xform(Vector3(1, 0, -1));
return int((result.x * 0.5 + 0.5) * p_for_pixel_width);
}
bool CameraMatrix::is_orthogonal() const {
return matrix[3][3] == 1.0;
}
real_t CameraMatrix::get_fov() const {
const real_t *matrix = (const real_t *)this->matrix;
Plane right_plane = Plane(matrix[3] - matrix[0],
matrix[7] - matrix[4],
matrix[11] - matrix[8],
-matrix[15] + matrix[12]);
right_plane.normalize();
if ((matrix[8] == 0) && (matrix[9] == 0)) {
return Math::rad2deg(Math::acos(Math::abs(right_plane.normal.x))) * 2.0;
} else {
// our frustum is asymmetrical need to calculate the left planes angle separately..
Plane left_plane = Plane(matrix[3] + matrix[0],
matrix[7] + matrix[4],
matrix[11] + matrix[8],
matrix[15] + matrix[12]);
left_plane.normalize();
return Math::rad2deg(Math::acos(Math::abs(left_plane.normal.x))) + Math::rad2deg(Math::acos(Math::abs(right_plane.normal.x)));
}
}
void CameraMatrix::make_scale(const Vector3 &p_scale) {
set_identity();
matrix[0][0] = p_scale.x;
matrix[1][1] = p_scale.y;
matrix[2][2] = p_scale.z;
}
void CameraMatrix::scale_translate_to_fit(const AABB &p_aabb) {
Vector3 min = p_aabb.position;
Vector3 max = p_aabb.position + p_aabb.size;
matrix[0][0] = 2 / (max.x - min.x);
matrix[1][0] = 0;
matrix[2][0] = 0;
matrix[3][0] = -(max.x + min.x) / (max.x - min.x);
matrix[0][1] = 0;
matrix[1][1] = 2 / (max.y - min.y);
matrix[2][1] = 0;
matrix[3][1] = -(max.y + min.y) / (max.y - min.y);
matrix[0][2] = 0;
matrix[1][2] = 0;
matrix[2][2] = 2 / (max.z - min.z);
matrix[3][2] = -(max.z + min.z) / (max.z - min.z);
matrix[0][3] = 0;
matrix[1][3] = 0;
matrix[2][3] = 0;
matrix[3][3] = 1;
}
CameraMatrix::operator Transform() const {
Transform tr;
const real_t *m = &matrix[0][0];
tr.basis.elements[0][0] = m[0];
tr.basis.elements[1][0] = m[1];
tr.basis.elements[2][0] = m[2];
tr.basis.elements[0][1] = m[4];
tr.basis.elements[1][1] = m[5];
tr.basis.elements[2][1] = m[6];
tr.basis.elements[0][2] = m[8];
tr.basis.elements[1][2] = m[9];
tr.basis.elements[2][2] = m[10];
tr.origin.x = m[12];
tr.origin.y = m[13];
tr.origin.z = m[14];
return tr;
}
CameraMatrix::CameraMatrix(const Transform &p_transform) {
const Transform &tr = p_transform;
real_t *m = &matrix[0][0];
m[0] = tr.basis.elements[0][0];
m[1] = tr.basis.elements[1][0];
m[2] = tr.basis.elements[2][0];
m[3] = 0.0;
m[4] = tr.basis.elements[0][1];
m[5] = tr.basis.elements[1][1];
m[6] = tr.basis.elements[2][1];
m[7] = 0.0;
m[8] = tr.basis.elements[0][2];
m[9] = tr.basis.elements[1][2];
m[10] = tr.basis.elements[2][2];
m[11] = 0.0;
m[12] = tr.origin.x;
m[13] = tr.origin.y;
m[14] = tr.origin.z;
m[15] = 1.0;
}
CameraMatrix::~CameraMatrix() {
}