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      1 /*
      2  * Copyright 2011 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 
      9 
     10 #ifndef GrGLIRect_DEFINED
     11 #define GrGLIRect_DEFINED
     12 
     13 #include "gl/GrGLInterface.h"
     14 #include "GrGLUtil.h"
     15 
     16 /**
     17  * Helper struct for dealing with the fact that Ganesh and GL use different
     18  * window coordinate systems (top-down vs bottom-up)
     19  */
     20 struct GrGLIRect {
     21     GrGLint   fLeft;
     22     GrGLint   fBottom;
     23     GrGLsizei fWidth;
     24     GrGLsizei fHeight;
     25 
     26     void pushToGLViewport(const GrGLInterface* gl) const {
     27         GR_GL_CALL(gl, Viewport(fLeft, fBottom, fWidth, fHeight));
     28     }
     29 
     30     void pushToGLScissor(const GrGLInterface* gl) const {
     31         GR_GL_CALL(gl, Scissor(fLeft, fBottom, fWidth, fHeight));
     32     }
     33 
     34     void setFromGLViewport(const GrGLInterface* gl) {
     35         GR_STATIC_ASSERT(sizeof(GrGLIRect) == 4*sizeof(GrGLint));
     36         GR_GL_GetIntegerv(gl, GR_GL_VIEWPORT, (GrGLint*) this);
     37     }
     38 
     39     // sometimes we have a SkIRect from the client that we
     40     // want to simultaneously make relative to GL's viewport
     41     // and (optionally) convert from top-down to bottom-up.
     42     void setRelativeTo(const GrGLIRect& glRect,
     43                        int leftOffset,
     44                        int topOffset,
     45                        int width,
     46                        int height,
     47                        GrSurfaceOrigin origin) {
     48         fLeft = glRect.fLeft + leftOffset;
     49         fWidth = width;
     50         if (kBottomLeft_GrSurfaceOrigin == origin) {
     51             fBottom = glRect.fBottom + (glRect.fHeight - topOffset - height);
     52         } else {
     53             fBottom = glRect.fBottom + topOffset;
     54         }
     55         fHeight = height;
     56 
     57         GrAssert(fLeft >= 0);
     58         GrAssert(fWidth >= 0);
     59         GrAssert(fBottom >= 0);
     60         GrAssert(fHeight >= 0);
     61     }
     62 
     63     bool contains(const GrGLIRect& glRect) const {
     64         return fLeft <= glRect.fLeft &&
     65                fBottom <= glRect.fBottom &&
     66                fLeft + fWidth >=  glRect.fLeft + glRect.fWidth &&
     67                fBottom + fHeight >=  glRect.fBottom + glRect.fHeight;
     68     }
     69 
     70     void invalidate() {fLeft = fWidth = fBottom = fHeight = -1;}
     71 
     72     bool operator ==(const GrGLIRect& glRect) const {
     73         return 0 == memcmp(this, &glRect, sizeof(GrGLIRect));
     74     }
     75 
     76     bool operator !=(const GrGLIRect& glRect) const {return !(*this == glRect);}
     77 };
     78 
     79 #endif
     80