Cleanup source tree

Move all C++ source files in the src subfolder. Adapted the cmake process accordingly and cleanup.

src/ImageShader.h

@@ -0,0 +1,76 @@
+#ifndef IMAGESHADER_H
+#define IMAGESHADER_H
+
+#include <string>
+#include <map>
+#include <sys/types.h>
+
+#include "Shader.h"
+
+class ImageShader : public Shader
+{
+
+public:
+    ImageShader();
+
+    void use() override;
+    void reset() override;
+    void accept(Visitor& v) override;
+    void copy(ImageShader const& S);
+
+    uint mask_texture;
+
+    // uniforms
+    float stipple;
+};
+
+class AlphaShader : public ImageShader
+{
+
+public:
+    AlphaShader();
+
+};
+
+
+class MaskShader : public Shader
+{
+
+public:
+    MaskShader();
+
+    void use() override;
+    void reset() override;
+    void accept(Visitor& v) override;
+    void copy(MaskShader const& S);
+
+    enum Modes {
+        NONE = 0,
+        PAINT = 1,
+        SHAPE = 2
+    };
+    uint mode;
+
+    enum Shapes {
+        ELIPSE = 0,
+        OBLONG = 1,
+        RECTANGLE = 2,
+        HORIZONTAL = 3,
+        VERTICAL = 4
+    };
+    uint shape;
+
+    // uniforms
+    glm::vec2 size;
+    float blur;
+
+    int option;
+    int effect;
+    glm::vec4 cursor;
+    glm::vec3 brush;
+
+    static const char* mask_names[3];
+    static const char* mask_shapes[5];
+};
+
+#endif // IMAGESHADER_H