97 lines
2.8 KiB
C
97 lines
2.8 KiB
C
#pragma once
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#include "math.h"
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#include "gryphn_vec3.h"
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typedef struct gnMat4x4 {
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float mat[4][4];
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} gnMat4x4;
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typedef gnMat4x4 gnMat4;
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static inline const gnMat4x4 gnIdentity() {
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return (gnMat4x4){
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.mat = {
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{ 1.0f, 0.0f, 0.0f, 0.0f },
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{ 0.0f, 1.0f, 0.0f, 0.0f },
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{ 0.0f, 0.0f, 1.0f, 0.0f },
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{ 0.0f, 0.0f, 0.0f, 1.0f }
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}
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};
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}
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static inline const gnMat4x4 gnOrthographic(
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float left, float right, float top, float bottom, float near, float far
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) {
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return (gnMat4x4){
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.mat = {
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{ (2)/(right-left), 0.0f, 0.0f, -((right+left)/(right-left)) },
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{ 0.0f, 2/(top-bottom), 0.0f, -((top+bottom)/(top-bottom)) },
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{ 0.0f, 0.0f, -2/(far-near), -((far+near)/(far-near)) },
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{ 0.0f, 0.0f, 0.0f, 1.0f }
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}
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};
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}
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static inline const gnMat4x4 gnProjection(
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float fov, float aspect, float near, float far
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) {
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float f = 1.0f / tan(fov * 0.5f);
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return (gnMat4x4){
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.mat = {
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{ f / aspect, 0.0f, 0.0f, 0.0f },
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{ 0.0f , f , 0.0f, 0.0f },
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{ 0.0f , 0.0f, (far + near) / (near - far), -1.0f },
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{ 0.0f , 0.0f, (2 * far * near) / (near - far), 0.0f }
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}
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};
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}
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static inline const gnMat4x4 gnTranslate(gnVec3 translation) {
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return (gnMat4x4) {
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.mat = {
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{ 1.0f, 0.0f, 0.0f, 0.0f },
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{ 0.0f, 1.0f, 0.0f, 0.0f },
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{ 0.0f, 0.0f, 1.0f, 0.0f },
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{ translation.x, translation.y, translation.z, 1.0f }
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}
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};
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}
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static inline const gnMat4x4 gnRotate(gnVec3 axis, float rotation) {
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float c = cos(rotation), s = sin(rotation);
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axis = gnVec3Normalize(axis);
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gnVec3 temp = {
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((1.0f - c) * axis.x),
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((1.0f - c) * axis.y),
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((1.0f - c) * axis.z)
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};
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gnMat4 rotate = {
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.mat = {
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{ c + temp.x * axis.x, temp.x * axis.y + s * axis.z, temp.x * axis.z - s * axis.y, 0.0f },
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{ temp.y * axis.x - s * axis.z, c + temp.y * axis.y, temp.y * axis.z + s * axis.x, 0.0f },
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{ temp.z * axis.x + s * axis.y, temp.z * axis.y - s * axis.x, c + temp.z * axis.z, 0.0f },
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{ 0.0f, 0.0f, 0.0f, 1.0f },
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}
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};
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return rotate;
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}
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// used GLMs lookAtLH from /glm/ext/matrix_transform.inl as a base
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static inline const gnMat4x4 gnLookAt(gnVec3 eye, gnVec3 center, gnVec3 up) {
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const gnVec3 f = gnVec3Normalize(gnVec3Subtract(center, eye));
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const gnVec3 s = gnVec3Normalize(gnVec3Cross(f, up));
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const gnVec3 u = gnVec3Cross(s, f);
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return (gnMat4x4) {
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.mat = {
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{ s.x, u.x, -f.x, 0.0f },
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{ s.y, u.y, -f.y, 0.0f },
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{ s.z, u.z, -f.z, 0.0f },
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{ -gnVec3Dot(s, eye), -gnVec3Dot(u, eye), gnVec3Dot(f, eye), 1.0f }
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}
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};
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}
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