rename src directory for vec4ops

4 files changed, 193 insertions, 0 deletions

diff --git a/src/vec4ops/rotations4d.cpp b/src/vec4ops/rotations4d.cpp
new file mode 100644
index 0000000..4943c7f
--- /dev/null
+++ b/src/vec4ops/rotations4d.cpp
@@ -0,0 +1,74 @@
+#include "raytracer/raytracer.h"
+#include "4dvecops/vec4ops.h"
+
+glm::mat4 Vec4Ops::getRotationMatrix4XY(
+        float angleRadians) {
+    glm::mat4 result;
+    result[0][0] = cos(angleRadians);
+    result[0][1] = -sin(angleRadians);
+    result[1][0] = sin(angleRadians);
+    result[1][1] = cos(angleRadians);
+    result[2][2] = 1;
+    result[3][3] = 1;
+    return result;
+}
+
+glm::mat4 Vec4Ops::getRotationMatrix4YZ(
+        float angleRadians) {
+    glm::mat4 result;
+    result[1][1] = cos(angleRadians);
+    result[1][2] = -sin(angleRadians);
+    result[2][1] = sin(angleRadians);
+    result[2][2] = cos(angleRadians);
+    result[0][0] = 1;
+    result[3][3] = 1;
+    return result;
+}
+
+glm::mat4 Vec4Ops::getRotationMatrix4ZX(
+        float angleRadians) {
+    glm::mat4 result;
+    result[2][2] = cos(angleRadians);
+    result[2][0] = -sin(angleRadians);
+    result[0][2] = sin(angleRadians);
+    result[0][0] = cos(angleRadians);
+    result[1][1] = 1;
+    result[3][3] = 1;
+    return result;
+}
+
+glm::mat4 Vec4Ops::getRotationMatrix4XW(
+        float angleRadians) {
+    glm::mat4 result;
+    result[0][0] = cos(angleRadians);
+    result[0][3] = -sin(angleRadians);
+    result[3][0] = sin(angleRadians);
+    result[3][3] = cos(angleRadians);
+    result[1][1] = 1;
+    result[2][2] = 1;
+    return result;
+}
+
+glm::mat4 Vec4Ops::getRotationMatrix4YW(
+        float angleRadians) {
+    glm::mat4 result;
+    result[1][1] = cos(angleRadians);
+    result[1][3] = -sin(angleRadians);
+    result[3][1] = sin(angleRadians);
+    result[3][3] = cos(angleRadians);
+    result[0][0] = 1;
+    result[2][2] = 1;
+    return result;
+}
+
+glm::mat4 Vec4Ops::getRotationMatrix4ZW(
+        float angleRadians) {
+    glm::mat4 result;
+    result[2][2] = cos(angleRadians);
+    result[2][3] = -sin(angleRadians);
+    result[3][2] = sin(angleRadians);
+    result[3][3] = cos(angleRadians);
+    result[0][0] = 1;
+    result[1][1] = 1;
+    return result;
+}
\ No newline at end of file
diff --git a/src/vec4ops/transform4d.cpp b/src/vec4ops/transform4d.cpp
new file mode 100644
index 0000000..5cc51f3
--- /dev/null
+++ b/src/vec4ops/transform4d.cpp
@@ -0,0 +1,18 @@
+#include "vec4ops.h"
+
+// this is used to transform a 4d point by a 4d matrix and its associated translation
+// this is motivated by the fact that glm does not support 5d matrices, so we cannot define a mat5 to encapsulate both the rotation and translation in one matrix
+// therefore, we break the 5d transformation into a 4d rotation and a 4d translation
+glm::vec4 Vec4Ops::transformPoint4(glm::vec4 point4,  glm::mat4 transformDirectionMatrix, glm::vec4 translationPointVector) {
+    // do the translation then direction
+    point4 = transformDirectionMatrix * point4;
+    point4 += translationPointVector;
+    return point4;
+}
+
+glm::vec4 Vec4Ops::inverseTransformPoint4(glm::vec4 point4,  glm::mat4 inverseTransformDirectionMatrix, glm::vec4 inverseTranslationPointVector) {
+    // do the direction then translation
+    point4 += inverseTranslationPointVector;
+    point4 = inverseTranslationPointVector * point4;
+    return point4;
+}
\ No newline at end of file
diff --git a/src/vec4ops/vec4ops.cpp b/src/vec4ops/vec4ops.cpp
new file mode 100644
index 0000000..80cebaf
--- /dev/null
+++ b/src/vec4ops/vec4ops.cpp
@@ -0,0 +1,64 @@
+#include <stdexcept>
+#include "vec4ops.h"
+
+// vector operations on 4d vectors,
+// reference: https://hollasch.github.io/ray4/Four-Space_Visualization_of_4D_Objects.html#chapter5
+
+glm::vec4 Vec4Ops::cross4(
+        glm::vec4 u,
+        glm::vec4 v,
+        glm::vec4 w) {
+    float a = (v[0] * w[1]) - (v[1] * w[0]);
+    float b = (v[0] * w[2]) - (v[2] * w[0]);
+    float c = (v[0] * w[3]) - (v[3] * w[0]);
+    float d = (v[1] * w[2]) - (v[2] * w[1]);
+    float e = (v[1] * w[3]) - (v[3] * w[1]);
+    float f = (v[2] * w[3]) - (v[3] * w[2]);
+
+    glm::vec4 result;
+    result[0] = (u[1] * f) - (u[2] * e) + (u[3] * d);
+    result[1] = -(u[0] * f) + (u[2] * c) - (u[3] * b);
+    result[2] = (u[0] * e) - (u[1] * c) + (u[3] * a);
+    result[3] = -(u[0] * d) + (u[1] * b) - (u[2] * a);
+
+    return result;
+}
+
+glm::vec4 Vec4Ops::dot4(
+        glm::vec4 u,
+        glm::vec4 v) {
+    return {u[0] * v[0], u[1] * v[1], u[2] * v[2], u[3] * v[3]};
+}
+
+glm::mat4 Vec4Ops::getViewMatrix4(
+        glm::vec4 fromPoint,
+        glm::vec4 toPoint,
+        glm::vec4 upVector,
+        glm::vec4 lookVector) {
+
+    // calculate e3 basis vector, the transformation col of view matrix
+    if (glm::distance(fromPoint, toPoint) < 0.0001f) {
+        throw std::runtime_error("fromPoint and toPoint are the same");
+    }
+    glm::vec4 e3 = glm::normalize(fromPoint - toPoint);
+
+    // calculate e2 basis vector, from the combinatory cross of up and over with e3
+    glm::vec4 e2 = cross4(upVector, lookVector, e3);
+    e2 = glm::normalize(e2);
+    if (glm::distance(e2, glm::vec4{0, 0, 0, 0}) < 0.0001f) {
+        throw std::runtime_error("invalid up vector");
+    }
+
+    // calculate e1 basis vector, from the cross of only the over vector
+    glm::vec4 e1 = cross4(lookVector, e3, e2);
+    e1 = glm::normalize(e1);
+    if (glm::distance(e1, glm::vec4{0, 0, 0, 0}) < 0.0001f) {
+        throw std::runtime_error("invalid over vector");
+    }
+
+    // calculate e0 basis vector, the 4d orthogonal vector to the other 3 bases
+    glm::vec4 e0 = cross4(e3, e2, e1);
+    e0 = glm::normalize(e0);
+
+    return {e2, e1, e0, e3};
+}
\ No newline at end of file
diff --git a/src/vec4ops/vec4ops.h b/src/vec4ops/vec4ops.h
new file mode 100644
index 0000000..d1c3ac8
--- /dev/null
+++ b/src/vec4ops/vec4ops.h
@@ -0,0 +1,37 @@
+//
+// Created by Michael Foiani on 12/8/23.
+//
+
+#ifndef PROJECTS_RAY_VEC4OPS_H
+#define PROJECTS_RAY_VEC4OPS_H
+
+#include <glm/glm.hpp>
+
+class Vec4Ops {
+public:
+
+    static glm::mat4 getRotationMatrix4XY(float angleRadians);
+
+    static glm::mat4 getRotationMatrix4YZ(float angleRadians);
+
+    static glm::mat4 getRotationMatrix4ZX(float angleRadians);
+
+    static glm::mat4 getRotationMatrix4XW(float angleRadians);
+
+    static glm::mat4 getRotationMatrix4YW(float angleRadians);
+
+    static glm::mat4 getRotationMatrix4ZW(float angleRadians);
+
+    static glm::vec4 transformPoint4(glm::vec4 point4, glm::mat4 transformDirectionMatrix, glm::vec4 translationPointVector);
+
+    static glm::vec4 inverseTransformPoint4(glm::vec4 point4, glm::mat4 inverseTransformDirectionMatrix,
+                                     glm::vec4 inverseTranslationPointVector);
+
+    static glm::vec4 cross4(glm::vec4 u, glm::vec4 v, glm::vec4 w);
+
+    static glm::vec4 dot4(glm::vec4 u, glm::vec4 v);
+
+    static glm::mat4 getViewMatrix4(glm::vec4 fromPoint, glm::vec4 toPoint, glm::vec4 upVector, glm::vec4 lookVector);
+};
+
+#endif //PROJECTS_RAY_VEC4OPS_H