WIP: Moved sources int src/, separated most of the source code from Perl.

The XS was left only for the unit / integration tests, and it links
libslic3r only. No wxWidgets are allowed to be used from Perl starting
from now.

src/slic3r/GUI/GLShader.hpp

@@ -0,0 +1,41 @@
+#ifndef slic3r_GLShader_hpp_
+#define slic3r_GLShader_hpp_
+
+#include "../../libslic3r/libslic3r.h"
+#include "../../libslic3r/Point.hpp"
+
+namespace Slic3r {
+
+class GLShader
+{
+public:
+    GLShader() :
+        fragment_program_id(0),
+        vertex_program_id(0),
+        shader_program_id(0)
+        {}
+    ~GLShader();
+
+    bool load_from_text(const char *fragment_shader, const char *vertex_shader);
+    bool load_from_file(const char* fragment_shader_filename, const char* vertex_shader_filename);
+
+    void release();
+
+    int  get_attrib_location(const char *name) const;
+    int  get_uniform_location(const char *name) const;
+
+    bool set_uniform(const char *name, float value) const;
+    bool set_uniform(const char* name, const float* matrix) const;
+
+    void enable() const;
+    void disable() const;
+
+    unsigned int    fragment_program_id;
+    unsigned int    vertex_program_id;
+    unsigned int    shader_program_id;
+    std::string     last_error;
+};
+
+}
+
+#endif /* slic3r_GLShader_hpp_ */