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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 GrIRect from the client that we
     40     // want to simultaneously make relative to GL's viewport
     41     // and 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         fLeft = glRect.fLeft + leftOffset;
     48         fWidth = width;
     49         fBottom = glRect.fBottom + (glRect.fHeight - topOffset - height);
     50         fHeight = height;
     51 
     52         GrAssert(fLeft >= 0);
     53         GrAssert(fWidth >= 0);
     54         GrAssert(fBottom >= 0);
     55         GrAssert(fHeight >= 0);
     56     }
     57 
     58     bool contains(const GrGLIRect& glRect) const {
     59         return fLeft <= glRect.fLeft &&
     60                fBottom <= glRect.fBottom &&
     61                fLeft + fWidth >=  glRect.fLeft + glRect.fWidth &&
     62                fBottom + fHeight >=  glRect.fBottom + glRect.fHeight;
     63     }
     64 
     65     void invalidate() {fLeft = fWidth = fBottom = fHeight = -1;}
     66 
     67     bool operator ==(const GrGLIRect& glRect) const {
     68         return 0 == memcmp(this, &glRect, sizeof(GrGLIRect));
     69     }
     70 
     71     bool operator !=(const GrGLIRect& glRect) const {return !(*this == glRect);}
     72 };
     73 
     74 #endif
     75