CS 345: Spring 2025

    class GShader {
    public:
        virtual ~GShader() {}
        
        virtual bool isOpaque() = 0;
        virtual bool setContext(const GMatrix& ctm) = 0;
        virtual void shadeRow(int x, int y, int count, GPixel row[]) = 0;
    };
    std::shared_ptr<GShader> GCreateBitmapShader(const GBitmap&, const GMatrix&);

    class GMatrix {
    public:
        GMatrix();
        static GMatrix Translate(float tx, float ty);
        static GMatrix Scale(float sx, float sy);
        static GMatrix Rotate(float radians);
        static GMatrix Concat(const GMatrix& secundo, const GMatrix& primo);
        std::optional invert() const;
        void mapPoints(GPoint dst[], const GPoint src[], int count) const;
        ...
    };

    class GCanvas {
    public:
        virtual void save() = 0;
        virtual void restore() = 0;
        virtual void concat(const GMatrix&) = 0;
        ...
    };
    

• Implement the missing methods on GMatrix.
• Implement save() restore() and concat() on your GCanvas subclass.
• Subclass GShader to implement the GCreateBitmapShader() factory.
• Implement GDrawSomething() to exercise matrices and shaders.


The pa3 directory should like something like this:
• apps contains the code for testing your code.
• expected contains sample output from the image tool to compare with your output.
• include contains class headers that your code can use.
• src contains common implementations needed for the tools.
• DO NOT EDIT/ADD/REMOVE anything in these sub-directories. You should only add files to the root of the directory.
• your_files any .cpp or .h files you need for your implementation. All of your work must be here.

To test your code...

            > make
            > ./image -e expected
            > ./tests
            > ./dbench
            > ./bench
        

         

Bench scores on the VM

    clear           2.54
    rects_blend     6.34
    rects_opaque    0.75
    rect_big        0.53
    rect_tiny       0.52
    quads_blend     6.87
    quads_opaque    1.08
    circles_large   3.51
    circles_tiny    0.52
    modes_0         1.43
    modes_x        24.73
    modes_1        15.05
    bitmap_opaque   3.37
    bitmap_alpha    6.61