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Diffstat (limited to 'gpu/include/GrStencil.h')
| -rw-r--r-- | gpu/include/GrStencil.h | 210 |
1 files changed, 0 insertions, 210 deletions
diff --git a/gpu/include/GrStencil.h b/gpu/include/GrStencil.h deleted file mode 100644 index 44a390d..0000000 --- a/gpu/include/GrStencil.h +++ /dev/null @@ -1,210 +0,0 @@ -/* - Copyright 2011 Google Inc. - - Licensed under the Apache License, Version 2.0 (the "License"); - you may not use this file except in compliance with the License. - You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - - Unless required by applicable law or agreed to in writing, software - distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the License for the specific language governing permissions and - limitations under the License. - */ - -#ifndef GrStencil_DEFINED -#define GrStencil_DEFINED - -#include "GrTypes.h" -/** - * Gr uses the stencil buffer to implement complex clipping inside the - * GrDrawTarget class. The GrDrawTarget makes a subset of the stencil buffer - * bits available for other uses by external code (clients). Client code can - * modify these bits. GrDrawTarget will ignore ref, mask, and writemask bits - * provided by clients that overlap the bits used to implement clipping. The - * client can use the getUsableStencilBits() function to find out how many - * client accessible stencil bits are available. - * - * When code outside the GrDrawTarget class uses the stencil buffer the contract - * is as follows: - * - * > Normal stencil funcs allow the GrGpu client to modify the client bits of - * the stencil buffer outside of the clip. - * > Special functions allow a test against the clip. These are more limited - * than the general stencil functions. - * > Client can assume all client bits are zero initially. - * > Client must ensure that after all its passes are finished it has only - * written to the color buffer in the region inside the clip. Furthermore, it - * must zero all client bits that were modifed (both inside and outside the - * clip). - */ - -/** - * Determines which pixels pass / fail the stencil test. - * Stencil test passes if (ref & mask) FUNC (stencil & mask) is true - */ -enum GrStencilFunc { - kAlways_StencilFunc = 0, - kNever_StencilFunc, - kGreater_StencilFunc, - kGEqual_StencilFunc, - kLess_StencilFunc, - kLEqual_StencilFunc, - kEqual_StencilFunc, - kNotEqual_StencilFunc, - - // Gr stores the current clip in the - // stencil buffer in the high bits that - // are not directly accessible modifiable - // via the GrDrawTarget interface. The below - // stencil funcs test against the current - // clip in addition to the GrDrawTarget - // client's stencil bits. - - // pass if inside the clip - kAlwaysIfInClip_StencilFunc, - kEqualIfInClip_StencilFunc, - kLessIfInClip_StencilFunc, - kLEqualIfInClip_StencilFunc, - kNonZeroIfInClip_StencilFunc, // this one forces the ref to be 0 - - // counts - kStencilFuncCount, - kClipStencilFuncCount = kNonZeroIfInClip_StencilFunc - - kAlwaysIfInClip_StencilFunc + 1, - kBasicStencilFuncCount = kStencilFuncCount - kClipStencilFuncCount -}; - -/** - * Operations to perform based on whether stencil test passed failed. - */ -enum GrStencilOp { - kKeep_StencilOp = 0, // preserve existing stencil value - kReplace_StencilOp, // replace with reference value from stencl test - kIncWrap_StencilOp, // increment and wrap at max - kIncClamp_StencilOp, // increment and clamp at max - kDecWrap_StencilOp, // decrement and wrap at 0 - kDecClamp_StencilOp, // decrement and clamp at 0 - kZero_StencilOp, // zero stencil bits - kInvert_StencilOp, // invert stencil bits - - kStencilOpCount -}; - -/** - * Struct representing stencil state. - */ -struct GrStencilSettings { - GrStencilOp fFrontPassOp; // op to perform when front faces pass - GrStencilOp fBackPassOp; // op to perform when back faces pass - GrStencilOp fFrontFailOp; // op to perform when front faces fail - GrStencilOp fBackFailOp; // op to perform when back faces fail - GrStencilFunc fFrontFunc; // test function for front faces - GrStencilFunc fBackFunc; // test function for back faces - unsigned int fFrontFuncMask; // mask for front face test - unsigned int fBackFuncMask; // mask for back face test - unsigned int fFrontFuncRef; // reference value for front face test - unsigned int fBackFuncRef; // reference value for back face test - unsigned int fFrontWriteMask; // stencil write mask for front faces - unsigned int fBackWriteMask; // stencil write mask for back faces - - bool operator == (const GrStencilSettings& s) const { - // make sure this is tightly packed. - GR_STATIC_ASSERT(0 == sizeof(GrStencilOp)%4); - GR_STATIC_ASSERT(0 == sizeof(GrStencilFunc)%4); - GR_STATIC_ASSERT(sizeof(GrStencilSettings) == - 4*sizeof(GrStencilOp) + - 2*sizeof(GrStencilFunc) + - 6*sizeof(unsigned int)); - return 0 == memcmp(this, &s, sizeof(GrStencilSettings)); - } - - bool operator != (const GrStencilSettings& s) const { - return !(*this == s); - } - - GrStencilSettings& operator =(const GrStencilSettings& s) { - memcpy(this, &s, sizeof(GrStencilSettings)); - return *this; - } - - void setSame(GrStencilOp passOp, - GrStencilOp failOp, - GrStencilFunc func, - unsigned int funcMask, - unsigned int funcRef, - unsigned int writeMask) { - fFrontPassOp = passOp; - fBackPassOp = passOp; - fFrontFailOp = failOp; - fBackFailOp = failOp; - fFrontFunc = func; - fBackFunc = func; - fFrontFuncMask = funcMask; - fBackFuncMask = funcMask; - fFrontFuncRef = funcRef; - fBackFuncRef = funcRef; - fFrontWriteMask = writeMask; - fBackWriteMask = writeMask; - } - - // canonical value for disabled stenciling - static const GrStencilSettings gDisabled; - void setDisabled() { - *this = gDisabled; - } - bool isDisabled() const { - return kKeep_StencilOp == fFrontPassOp && - kKeep_StencilOp == fBackPassOp && - kKeep_StencilOp == fFrontFailOp && - kKeep_StencilOp == fBackFailOp && - kAlways_StencilFunc == fFrontFunc && - kAlways_StencilFunc == fBackFunc; - } - void invalidate() { - // just write an illegal value to the first member - fFrontPassOp = (GrStencilOp)-1; - } - -private: - friend class GrGpu; - - enum { - kMaxStencilClipPasses = 2 // maximum number of passes to add a clip - // element to the stencil buffer. - }; - - /** - * Given a thing to draw into the stencil clip, a fill type, and a set op - * this function determines: - * 1. Whether the thing can be draw directly to the stencil clip or - * needs to be drawn to the client portion of the stencil first. - * 2. How many passes are needed. - * 3. What those passes are. - * 4. The fill rule that should actually be used to render (will - * always be non-inverted). - * - * @param op the set op to combine this element with the - * existing clip - * @param stencilClipMask mask with just the stencil bit used for clipping - * enabled. - * @param invertedFill is this path inverted - * @param numPasses out: the number of passes needed to add the - * element to the clip. - * @param settings out: the stencil settings to use for each pass - * - * @return true if the clip element's geometry can be drawn directly to the - * stencil clip bit. Will only be true if canBeDirect is true. - * numPasses will be 1 if return value is true. - */ - static bool GetClipPasses(GrSetOp op, - bool canBeDirect, - unsigned int stencilClipMask, - bool invertedFill, - int* numPasses, - GrStencilSettings settings[kMaxStencilClipPasses]); -}; - -#endif |