From 118980e02e59ff31871df59dce257075394f3533 Mon Sep 17 00:00:00 2001 From: Aaditya Dhruv Date: Sun, 25 Jan 2026 15:10:37 -0600 Subject: wip --- include/cglm/clipspace/persp_lh_zo.h | 387 +++++++++++++++++++++++++++++++++++ 1 file changed, 387 insertions(+) create mode 100644 include/cglm/clipspace/persp_lh_zo.h (limited to 'include/cglm/clipspace/persp_lh_zo.h') diff --git a/include/cglm/clipspace/persp_lh_zo.h b/include/cglm/clipspace/persp_lh_zo.h new file mode 100644 index 0000000..de89643 --- /dev/null +++ b/include/cglm/clipspace/persp_lh_zo.h @@ -0,0 +1,387 @@ +/* + * 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*/ -- cgit