add versor dependency, generate rotor matrix

.gitmodules

@@ -8,3 +8,6 @@
 [submodule "vendor/glm"]
 	path = vendor/glm
 	url = https://github.com/g-truc/glm.git
+[submodule "vendor/versor"]
+	path = vendor/versor
+	url = https://github.com/wolftype/versor.git

CMakeLists.txt

@@ -14,5 +14,9 @@ add_subdirectory(vendor/glfw)
 option(GLM_TEST_ENABLE OFF)
 add_subdirectory(vendor/glm)
 
+add_subdirectory(vendor/versor)
+get_property(VSR_INCLUDE_DIR GLOBAL PROPERTY VSR_INCLUDE_DIR)
+target_include_directories(vsr PUBLIC ${VSR_INCLUDE_DIR})
+
 add_subdirectory(framework)
 add_subdirectory(simplex)

simplex/CMakeLists.txt

@@ -7,6 +7,7 @@ target_link_libraries(${PROJECT_NAME}
         glad
         glm
         glfw
+        vsr
         framework)
 
 target_include_directories(${PROJECT_NAME}

simplex/include/rotor.h

@@ -1,80 +1,27 @@
 #ifndef GL_TEMPLATE_ROTOR_H
 #define GL_TEMPLATE_ROTOR_H
 
+#include <glm/vec4.hpp>
 #include <glm/mat4x4.hpp>
+#include <glm/gtc/type_ptr.hpp>
+#include <vsr/vsr.h>
 
-#include <math.h>
+glm::mat4 rotor(glm::vec4 u, glm::vec4 v, float angle) {
+    using Vec = vsr::euclidean_vector<4, float>;
 
-glm::mat4 rotor_xy(float t) {
-    float c = cos(t);
-    float s = sin(t);
+    auto eu = *((Vec *) (void *) &u);
+    auto ev = *((Vec *) (void *) &v);
 
-    return glm::mat4(
-        +c, s, 0, 0,
-        -s, c, 0, 0,
-        +0, 0, 1, 0,
-        +0, 0, 0, 1
-    );
-}
+    auto biv = (eu ^ ev).unit() * angle;
 
-glm::mat4 rotor_xz(float t) {
-    float c = cos(t);
-    float s = sin(t);
+    Vec col[4] = {
+        Vec(1, 0, 0, 0).rotate(biv),
+        Vec(0, 1, 0, 0).rotate(biv),
+        Vec(0, 0, 1, 0).rotate(biv),
+        Vec(0, 0, 0, 1).rotate(biv)
+    };
 
-    return glm::mat4(
-        +c, 0, s, 0,
-        +0, 1, 0, 0,
-        -s, 0, c, 0,
-        +0, 0, 0, 1
-    );
-}
-
-glm::mat4 rotor_xw(float t) {
-    float c = cos(t);
-    float s = sin(t);
-
-    return glm::mat4(
-        +c, 0, 0, s,
-        +0, 1, 0, 0,
-        +0, 0, 1, 0,
-        -s, 0, 0, c
-    );
-}
-
-glm::mat4 rotor_yz(float t) {
-    float c = cos(t);
-    float s = sin(t);
-
-    return glm::mat4(
-        1, +0, 0, 0,
-        0, +c, s, 0,
-        0, -s, c, 0,
-        0, +0, 0, 1
-    );
-}
-
-glm::mat4 rotor_yw(float t) {
-    float c = cos(t);
-    float s = sin(t);
-
-    return glm::mat4(
-        1, +0, 0, 0,
-        0, +c, 0, s,
-        0, +0, 1, 0,
-        0, -s, 0, c
-    );
-}
-
-glm::mat4 rotor_zw(float t) {
-    float c = cos(t);
-    float s = sin(t);
-
-    return glm::mat4(
-        1, 0, +0, 0,
-        0, 1, +0, 0,
-        0, 0, +c, s,
-        0, 0, -s, c
-    );
+    return glm::make_mat4((float *) col);
 }
 
 #endif //GL_TEMPLATE_ROTOR_H

simplex/src/main.cpp

@@ -113,7 +113,9 @@ class GLApp : public App {
         glfwGetFramebufferSize(getWindow(), &width, &height);
         float ratio = (float) width / height;
 
-        matrices.model = rotor_yw(getTime() / 5) * rotor_xz(getTime() / 2);
+        matrices.model =
+            rotor(glm::vec4(1,0,0,0), glm::vec4(0,0,1,0), getTime() / 4) *
+            rotor(glm::vec4(0,1,0,0), glm::vec4(0,0,0,1), getTime() / 4);
 
         matrices.view = glm::lookAt(glm::vec3(0, 0, -2), glm::vec3(0, 0, 0), glm::vec3(0, 1, 0));
         matrices.proj = glm::perspective(1.f, ratio, 0.1f, 10.0f);