Migrate to NanoGUI / Eigen for GUI and linear algebra.

Also introduce a GUI play/pause button.

vis/include/cgl/shaderprogram.hpp

@@ -0,0 +1,46 @@
+#pragma once
+
+#include <string>
+#include <utility>
+
+#include <nanogui/opengl.h>
+
+#include <cgl/error.hpp>
+#include <cgl/shader.hpp>
+#include <cgl/program.hpp>
+
+#include <util.hpp>
+
+namespace cgl{
+    template<GLenum mode>
+    class ShaderProgram : public Program {
+    public:
+        ShaderProgram() : Program() {
+            glProgramParameteri(id, GL_PROGRAM_SEPARABLE, GL_TRUE);
+        }
+
+        ShaderProgram(const std::string &src) : ShaderProgram() {
+            Shader<mode> sh(src);
+
+            attach(sh);
+
+            if (!link())
+                throw ShaderError(get_info_log());
+
+            detach(sh);
+        }
+
+        static ShaderProgram<mode> file(const std::string &name) {
+            return ShaderProgram<mode>(utilReadFile(name));
+        }
+    };
+
+    namespace pgm {
+        using vert = ShaderProgram<GL_VERTEX_SHADER>;
+        using tcs = ShaderProgram<GL_TESS_CONTROL_SHADER>;
+        using tes = ShaderProgram<GL_TESS_EVALUATION_SHADER>;
+        using geom = ShaderProgram<GL_GEOMETRY_SHADER>;
+        using frag = ShaderProgram<GL_FRAGMENT_SHADER>;
+        using comp = ShaderProgram<GL_COMPUTE_SHADER>;
+    }
+}