frillrun/include/cglm/clipspace/persp_lh_zo.h

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2024-08-24 04:47:58 +00:00
/*
* Copyright (c), Recep Aslantas.
*
* MIT License (MIT), http://opensource.org/licenses/MIT
* Full license can be found in the LICENSE file
*/
/*
Functions:
CGLM_INLINE void glm_frustum_lh_zo(float left, float right,
float bottom, float top,
float nearZ, float farZ,
mat4 dest)
CGLM_INLINE void glm_perspective_lh_zo(float fovy,
float aspect,
float nearZ,
float farZ,
mat4 dest)
CGLM_INLINE void glm_perspective_default_lh_zo(float aspect, mat4 dest)
CGLM_INLINE void glm_perspective_resize_lh_zo(float aspect, mat4 proj)
CGLM_INLINE void glm_persp_move_far_lh_zo(mat4 proj,
float deltaFar)
CGLM_INLINE void glm_persp_decomp_lh_zo(mat4 proj,
float * __restrict nearZ,
float * __restrict farZ,
float * __restrict top,
float * __restrict bottom,
float * __restrict left,
float * __restrict right)
CGLM_INLINE void glm_persp_decompv_lh_zo(mat4 proj,
float dest[6])
CGLM_INLINE void glm_persp_decomp_x_lh_zo(mat4 proj,
float * __restrict left,
float * __restrict right)
CGLM_INLINE void glm_persp_decomp_y_lh_zo(mat4 proj,
float * __restrict top,
float * __restrict bottom)
CGLM_INLINE void glm_persp_decomp_z_lh_zo(mat4 proj,
float * __restrict nearZ,
float * __restrict farZ)
CGLM_INLINE void glm_persp_decomp_far_lh_zo(mat4 proj, float * __restrict farZ)
CGLM_INLINE void glm_persp_decomp_near_lh_zo(mat4 proj, float * __restrict nearZ)
CGLM_INLINE void glm_persp_sizes_lh_zo(mat4 proj, float fovy, vec4 dest)
*/
#ifndef cglm_persp_lh_zo_h
#define cglm_persp_lh_zo_h
#include "../common.h"
#include "persp.h"
/*!
* @brief set up perspective peprojection matrix with a left-hand coordinate
* system and a clip-space of [0, 1].
*
* @param[in] left viewport.left
* @param[in] right viewport.right
* @param[in] bottom viewport.bottom
* @param[in] top viewport.top
* @param[in] nearZ near clipping plane
* @param[in] farZ far clipping plane
* @param[out] dest result matrix
*/
CGLM_INLINE
void
glm_frustum_lh_zo(float left, float right,
float bottom, float top,
float nearZ, float farZ,
mat4 dest) {
float rl, tb, fn, nv;
glm_mat4_zero(dest);
rl = 1.0f / (right - left);
tb = 1.0f / (top - bottom);
fn =-1.0f / (farZ - nearZ);
nv = 2.0f * nearZ;
dest[0][0] = nv * rl;
dest[1][1] = nv * tb;
dest[2][0] = (right + left) * rl;
dest[2][1] = (top + bottom) * tb;
dest[2][2] =-farZ * fn;
dest[2][3] = 1.0f;
dest[3][2] = farZ * nearZ * fn;
}
/*!
* @brief set up perspective projection matrix with a left-hand coordinate
* system and a clip-space of [0, 1].
*
* @param[in] fovy field of view angle
* @param[in] aspect aspect ratio ( width / height )
* @param[in] nearZ near clipping plane
* @param[in] farZ far clipping planes
* @param[out] dest result matrix
*/
CGLM_INLINE
void
glm_perspective_lh_zo(float fovy,
float aspect,
float nearZ,
float farZ,
mat4 dest) {
float f, fn;
glm_mat4_zero(dest);
f = 1.0f / tanf(fovy * 0.5f);
fn = 1.0f / (nearZ - farZ);
dest[0][0] = f / aspect;
dest[1][1] = f;
dest[2][2] =-farZ * fn;
dest[2][3] = 1.0f;
dest[3][2] = nearZ * farZ * fn;
}
/*!
* @brief extend perspective projection matrix's far distance with a
* left-hand coordinate system and a clip-space with depth values
* from zero to one.
*
* this function does not guarantee far >= near, be aware of that!
*
* @param[in, out] proj projection matrix to extend
* @param[in] deltaFar distance from existing far (negative to shink)
*/
CGLM_INLINE
void
glm_persp_move_far_lh_zo(mat4 proj, float deltaFar) {
float fn, farZ, nearZ, p22, p32;
p22 = -proj[2][2];
p32 = proj[3][2];
nearZ = p32 / p22;
farZ = p32 / (p22 + 1.0f) + deltaFar;
fn = 1.0f / (nearZ - farZ);
proj[2][2] = -farZ * fn;
proj[3][2] = nearZ * farZ * fn;
}
/*!
* @brief set up perspective projection matrix with default near/far
* and angle values with a left-hand coordinate system and a
* clip-space of [0, 1].
*
* @param[in] aspect aspect ratio ( width / height )
* @param[out] dest result matrix
*/
CGLM_INLINE
void
glm_perspective_default_lh_zo(float aspect, mat4 dest) {
glm_perspective_lh_zo(GLM_PI_4f, aspect, 0.01f, 100.0f, dest);
}
/*!
* @brief resize perspective matrix by aspect ratio ( width / height )
* this makes very easy to resize proj matrix when window /viewport
* reized
*
* @param[in] aspect aspect ratio ( width / height )
* @param[in, out] proj perspective projection matrix
*/
CGLM_INLINE
void
glm_perspective_resize_lh_zo(float aspect, mat4 proj) {
if (proj[0][0] == 0.0f)
return;
proj[0][0] = proj[1][1] / aspect;
}
/*!
* @brief decomposes frustum values of perspective projection
* with angle values with a left-hand coordinate system and a
* clip-space of [0, 1].
*
* @param[in] proj perspective projection matrix
* @param[out] nearZ near
* @param[out] farZ far
* @param[out] top top
* @param[out] bottom bottom
* @param[out] left left
* @param[out] right right
*/
CGLM_INLINE
void
glm_persp_decomp_lh_zo(mat4 proj,
float * __restrict nearZ, float * __restrict farZ,
float * __restrict top, float * __restrict bottom,
float * __restrict left, float * __restrict right) {
float m00, m11, m20, m21, m22, m32, n, f;
float n_m11, n_m00;
m00 = proj[0][0];
m11 = proj[1][1];
m20 = proj[2][0];
m21 = proj[2][1];
m22 =-proj[2][2];
m32 = proj[3][2];
n = m32 / m22;
f = m32 / (m22 + 1.0f);
n_m11 = n / m11;
n_m00 = n / m00;
*nearZ = n;
*farZ = f;
*bottom = n_m11 * (m21 - 1.0f);
*top = n_m11 * (m21 + 1.0f);
*left = n_m00 * (m20 - 1.0f);
*right = n_m00 * (m20 + 1.0f);
}
/*!
* @brief decomposes frustum values of perspective projection
* with angle values with a left-hand coordinate system and a
* clip-space of [0, 1].
* this makes easy to get all values at once
*
* @param[in] proj perspective projection matrix
* @param[out] dest array
*/
CGLM_INLINE
void
glm_persp_decompv_lh_zo(mat4 proj, float dest[6]) {
glm_persp_decomp_lh_zo(proj, &dest[0], &dest[1], &dest[2],
&dest[3], &dest[4], &dest[5]);
}
/*!
* @brief decomposes left and right values of perspective projection (ZO).
* x stands for x axis (left / right axis)
*
* @param[in] proj perspective projection matrix
* @param[out] left left
* @param[out] right right
*/
CGLM_INLINE
void
glm_persp_decomp_x_lh_zo(mat4 proj,
float * __restrict left,
float * __restrict right) {
float nearZ, m20, m00;
m00 = proj[0][0];
m20 = proj[2][0];
nearZ = proj[3][2] / (proj[3][3]);
*left = nearZ * (m20 - 1.0f) / m00;
*right = nearZ * (m20 + 1.0f) / m00;
}
/*!
* @brief decomposes top and bottom values of perspective projection
* with angle values with a left-hand coordinate system and a
* clip-space of [0, 1].
* y stands for y axis (top / bottom axis)
*
* @param[in] proj perspective projection matrix
* @param[out] top top
* @param[out] bottom bottom
*/
CGLM_INLINE
void
glm_persp_decomp_y_lh_zo(mat4 proj,
float * __restrict top,
float * __restrict bottom) {
float nearZ, m21, m11;
m21 = proj[2][1];
m11 = proj[1][1];
nearZ = proj[3][2] / (proj[3][3]);
*bottom = nearZ * (m21 - 1) / m11;
*top = nearZ * (m21 + 1) / m11;
}
/*!
* @brief decomposes near and far values of perspective projection
* with angle values with a left-hand coordinate system and a
* clip-space of [0, 1].
* z stands for z axis (near / far axis)
*
* @param[in] proj perspective projection matrix
* @param[out] nearZ near
* @param[out] farZ far
*/
CGLM_INLINE
void
glm_persp_decomp_z_lh_zo(mat4 proj,
float * __restrict nearZ,
float * __restrict farZ) {
float m32, m22;
m32 = proj[3][2];
m22 = -proj[2][2];
*nearZ = m32 / m22;
*farZ = m32 / (m22 + 1.0f);
}
/*!
* @brief decomposes far value of perspective projection
* with angle values with a left-hand coordinate system and a
* clip-space of [0, 1].
*
* @param[in] proj perspective projection matrix
* @param[out] farZ far
*/
CGLM_INLINE
void
glm_persp_decomp_far_lh_zo(mat4 proj, float * __restrict farZ) {
*farZ = proj[3][2] / (-proj[2][2] + 1.0f);
}
/*!
* @brief decomposes near value of perspective projection
* with angle values with a left-hand coordinate system and a
* clip-space of [0, 1].
*
* @param[in] proj perspective projection matrix
* @param[out] nearZ near
*/
CGLM_INLINE
void
glm_persp_decomp_near_lh_zo(mat4 proj, float * __restrict nearZ) {
*nearZ = proj[3][2] / -proj[2][2];
}
/*!
* @brief returns sizes of near and far planes of perspective projection
* with a left-hand coordinate system and a
* clip-space of [0, 1].
*
* @param[in] proj perspective projection matrix
* @param[in] fovy fovy (see brief)
* @param[out] dest sizes order: [Wnear, Hnear, Wfar, Hfar]
*/
CGLM_INLINE
void
glm_persp_sizes_lh_zo(mat4 proj, float fovy, vec4 dest) {
float t, a, nearZ, farZ;
t = 2.0f * tanf(fovy * 0.5f);
a = glm_persp_aspect(proj);
glm_persp_decomp_z_lh_zo(proj, &nearZ, &farZ);
dest[1] = t * nearZ;
dest[3] = t * farZ;
dest[0] = a * dest[1];
dest[2] = a * dest[3];
}
/*!
* @brief returns field of view angle along the Y-axis (in radians)
* with a left-hand coordinate system and a clip-space of [0, 1].
*
* if you need to degrees, use glm_deg to convert it or use this:
* fovy_deg = glm_deg(glm_persp_fovy(projMatrix))
*
* @param[in] proj perspective projection matrix
*/
CGLM_INLINE
float
glm_persp_fovy_lh_zo(mat4 proj) {
return glm_persp_fovy(proj);
}
/*!
* @brief returns aspect ratio of perspective projection
* with a left-hand coordinate system and a clip-space of [0, 1].
*
* @param[in] proj perspective projection matrix
*/
CGLM_INLINE
float
glm_persp_aspect_lh_zo(mat4 proj) {
return glm_persp_aspect(proj);
}
#endif /*cglm_persp_lh_zo_h*/