gm: add a flag to force perspective usage in all gms

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 "SkBitmapDevice.h"
 #include "SkCanvas.h"
+#include "SkCommandLineFlags.h"
 #include "SkPaint.h"
 #include "SkSize.h"
 #include "SkString.h"
 #include "SkTRegistry.h"
 
 #if SK_SUPPORT_GPU
 #include "GrContext.h"
 #endif
 
+DECLARE_bool(forcePerspectiveMatrix);
+
 #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_));
 
 namespace skiagm {
 
     static inline SkISize make_isize(int w, int h) {
         SkISize sz;
         sz.set(w, h);
         return sz;
@@ skipping 33 matching lines @@
             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 {

[reed1, 2013/09/23 18:48:40]

I think we could generalize this guy a little for this CL:

1. I think you should concat w/ onGetInitialTransform(), instead of either/or
2. Perhaps gm itself has a setter (which gmmain.cpp can call) that accepts an
initial matrix.

#2 means you don't need to know about any flags here, just a matrix data blob in
the base-class of gm. THen the code would be something like

SkMatrix getInitialMatrix() const {
    SkMatrix matrix = fStarterMatrix;   // identity or set by the new
setStarterMatrix(...) on base class
    matrix.preConcat(this->onGetInitialTransform());
    return matrix;
}

[edisonn, 2013/09/23 19:38:04]

Done.

+            if (FLAGS_forcePerspectiveMatrix) {
+                SkMatrix perspective;
+                perspective.setIdentity();
+                perspective.setPerspY(SkScalarDiv(SK_Scalar1, SkIntToScalar(1000)));
+                perspective.setSkewX(SkScalarDiv(SkIntToScalar(8), SkIntToScalar(25)));
+                return perspective;
+            }
             return this->onGetInitialTransform();
         }
 
         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);
 
@@ skipping 35 matching lines @@
         SkColor  fBGColor;
         bool     fCanvasIsDeferred; // work-around problem in srcmode.cpp
         bool     fHaveCalledOnceBeforeDraw;
         bool     fIgnoreFailures; // whether to file any failures as failure-ignored
     };
 
     typedef SkTRegistry<GM*(*)(void*)> GMRegistry;
 }
 
 #endif