gm/gm.h

/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef skiagm_DEFINED
#define skiagm_DEFINED

#include "SkBitmap.h"
#include "SkCanvas.h"
#include "SkPaint.h"
#include "SkSize.h"
#include "SkString.h"
#include "SkTRegistry.h"
#include "sk_tool_utils.h"

#if SK_SUPPORT_GPU
#include "GrContext.h"
#endif

#define DEF_GM(code) \
    static skiagm::GM*          SK_MACRO_APPEND_LINE(F_)(void*) { code; } \
    static skiagm::GMRegistry   SK_MACRO_APPEND_LINE(R_)(SK_MACRO_APPEND_LINE(F_));

// See colorwheel.cpp for example usage.
#define DEF_SIMPLE_GM(NAME, CANVAS, W, H)                               \
    static void SK_MACRO_CONCAT(NAME, _GM)(SkCanvas* CANVAS);           \
    DEF_GM( return SkNEW_ARGS(skiagm::SimpleGM,                         \
                              (SkString(#NAME),                         \
                               SK_MACRO_CONCAT(NAME, _GM),              \
                               SkISize::Make(W, H))); )                 \
    void SK_MACRO_CONCAT(NAME, _GM)(SkCanvas* CANVAS)

namespace skiagm {

    class GM {
    public:
        GM();
        virtual ~GM();

        enum Mode {
            kGM_Mode,
            kSample_Mode,
            kBench_Mode,
        };

        void setMode(Mode mode) { fMode = mode; }
        Mode getMode() const { return fMode; }

        void draw(SkCanvas*);
        void drawBackground(SkCanvas*);
        void drawContent(SkCanvas*);

        SkISize getISize() { return this->onISize(); }
        const char* getName();

        virtual bool runAsBench() const { return false; }

        SkScalar width() {
            return SkIntToScalar(this->getISize().width());
        }
        SkScalar height() {
            return SkIntToScalar(this->getISize().height());
        }

        // TODO(vandebo) Instead of exposing this, we should run all the GMs
        // with and without an initial transform.
        // Most GMs will return the identity matrix, but some PDFs tests
        // require setting the initial transform.
        SkMatrix getInitialTransform() const {
            SkMatrix matrix = fStarterMatrix;
            matrix.preConcat(this->onGetInitialTransform());
            return matrix;
        }

        SkColor getBGColor() const { return fBGColor; }
        void setBGColor(SkColor);

        // helper: fill a rect in the specified color based on the
        // GM's getISize bounds.
        void drawSizeBounds(SkCanvas*, SkColor);

        bool isCanvasDeferred() const { return fCanvasIsDeferred; }
        void setCanvasIsDeferred(bool isDeferred) {
            fCanvasIsDeferred = isDeferred;
        }

        const SkMatrix& getStarterMatrix() { return fStarterMatrix; }
        void setStarterMatrix(const SkMatrix& matrix) {
            fStarterMatrix = matrix;
        }

    protected:
        /** draws a standard message that the GM is only intended to be used with the GPU.*/
        void drawGpuOnlyMessage(SkCanvas*);
        virtual void onOnceBeforeDraw() {}
        virtual void onDraw(SkCanvas*) = 0;
        virtual void onDrawBackground(SkCanvas*);
        virtual SkISize onISize() = 0;
        virtual SkString onShortName() = 0;

        virtual SkMatrix onGetInitialTransform() const { return SkMatrix::I(); }

    private:
        Mode     fMode;
        SkString fShortName;
        SkColor  fBGColor;
        bool     fCanvasIsDeferred; // work-around problem in srcmode.cpp
        bool     fHaveCalledOnceBeforeDraw;
        SkMatrix fStarterMatrix;
    };

    typedef SkTRegistry<GM*(*)(void*)> GMRegistry;

    class SimpleGM : public skiagm::GM {
    public:
        SimpleGM(const SkString& name,
                 void (*drawProc)(SkCanvas*),
                 const SkISize& size)
            : fName(name), fDrawProc(drawProc), fSize(size) {}
    protected:
        void onDraw(SkCanvas* canvas) SK_OVERRIDE;
        SkISize onISize() SK_OVERRIDE;
        SkString onShortName() SK_OVERRIDE;
    private:
        SkString fName;
        void (*fDrawProc)(SkCanvas*);
        SkISize fSize;
    };
}

#endif