C++ GrDrawState::getCoverageColor方法代码示例

bool GrAAHairLinePathRenderer::createLineGeom(const SkPath& path,
                                              GrDrawTarget* target,
                                              const PtArray& lines,
                                              int lineCnt,
                                              GrDrawTarget::AutoReleaseGeometry* arg,
                                              SkRect* devBounds) {
    GrDrawState* drawState = target->drawState();

    const SkMatrix& viewM = drawState->getViewMatrix();

    int vertCnt = kVertsPerLineSeg * lineCnt;

    drawState->setVertexAttribs<gHairlineLineAttribs>(SK_ARRAY_COUNT(gHairlineLineAttribs),
                                                      sizeof(LineVertex));

    if (!arg->set(target, vertCnt, 0)) {
        return false;
    }

    LineVertex* verts = reinterpret_cast<LineVertex*>(arg->vertices());

    const SkMatrix* toSrc = NULL;
    SkMatrix ivm;

    if (viewM.hasPerspective()) {
        if (viewM.invert(&ivm)) {
            toSrc = &ivm;
        }
    }
    devBounds->set(lines.begin(), lines.count());
    for (int i = 0; i < lineCnt; ++i) {
        add_line(&lines[2*i], toSrc, drawState->getCoverageColor(), &verts);
    }
    // All the verts computed by add_line are within sqrt(1^2 + 0.5^2) of the end points.
    static const SkScalar kSqrtOfOneAndAQuarter = 1.118f;
    // Add a little extra to account for vector normalization precision.
    static const SkScalar kOutset = kSqrtOfOneAndAQuarter + SK_Scalar1 / 20;
    devBounds->outset(kOutset, kOutset);

    return true;
}

//.........这里部分代码省略.........
        for (int s = firstEffectiveCoverageStage; s < drawState.numCoverageStages(); ++s) {
            effectKeys[currEffectKey++] =
                get_key_and_update_stats(drawState.getCoverageStage(s), gpu->glCaps(),
                                         requiresLocalCoordAttrib, &readsDst, &readFragPosition,
                                         &hasVertexCode);
        }
    }

    header->fHasVertexCode = hasVertexCode || requiresLocalCoordAttrib;
    header->fEmitsPointSize = isPoints;

    // Currently the experimental GS will only work with triangle prims (and it doesn't do anything
    // other than pass through values from the VS to the FS anyway).
#if GR_GL_EXPERIMENTAL_GS
#if 0
    header->fExperimentalGS = gpu->caps().geometryShaderSupport();
#else
    header->fExperimentalGS = false;
#endif
#endif
    bool defaultToUniformInputs = GR_GL_NO_CONSTANT_ATTRIBUTES || gpu->caps()->pathRenderingSupport();

    if (colorIsTransBlack) {
        header->fColorInput = kTransBlack_ColorInput;
    } else if (colorIsSolidWhite) {
        header->fColorInput = kSolidWhite_ColorInput;
    } else if (defaultToUniformInputs && !requiresColorAttrib) {
        header->fColorInput = kUniform_ColorInput;
    } else {
        header->fColorInput = kAttribute_ColorInput;
        header->fHasVertexCode = true;
    }

    bool covIsSolidWhite = !requiresCoverageAttrib && 0xffffffff == drawState.getCoverageColor();

    if (skipCoverage) {
        header->fCoverageInput = kTransBlack_ColorInput;
    } else if (covIsSolidWhite || !inputCoverageIsUsed) {
        header->fCoverageInput = kSolidWhite_ColorInput;
    } else if (defaultToUniformInputs && !requiresCoverageAttrib) {
        header->fCoverageInput = kUniform_ColorInput;
    } else {
        header->fCoverageInput = kAttribute_ColorInput;
        header->fHasVertexCode = true;
    }

    if (readsDst) {
        SkASSERT(NULL != dstCopy || gpu->caps()->dstReadInShaderSupport());
        const GrTexture* dstCopyTexture = NULL;
        if (NULL != dstCopy) {
            dstCopyTexture = dstCopy->texture();
        }
        header->fDstReadKey = GrGLShaderBuilder::KeyForDstRead(dstCopyTexture, gpu->glCaps());
        SkASSERT(0 != header->fDstReadKey);
    } else {
        header->fDstReadKey = 0;
    }

    if (readFragPosition) {
        header->fFragPosKey = GrGLShaderBuilder::KeyForFragmentPosition(drawState.getRenderTarget(),
                                                                      gpu->glCaps());
    } else {
        header->fFragPosKey = 0;
    }

    // Record attribute indices

//.........这里部分代码省略.........
        }
    }
    if (!effectKeySuccess) {
        desc->fKey.reset();
        return false;
    }

    // Because header is a pointer into the dynamic array, we can't push any new data into the key
    // below here.

    header->fRequiresVertexShader = requiresVertexShader || requiresLocalCoordAttrib;
    header->fEmitsPointSize = GrGpu::kDrawPoints_DrawType == drawType;

    // Currently the experimental GS will only work with triangle prims (and it doesn't do anything
    // other than pass through values from the VS to the FS anyway).
#if GR_GL_EXPERIMENTAL_GS
#if 0
    header->fExperimentalGS = gpu->caps().geometryShaderSupport();
#else
    header->fExperimentalGS = false;
#endif
#endif
    bool defaultToUniformInputs = GR_GL_NO_CONSTANT_ATTRIBUTES || gpu->caps()->pathRenderingSupport();

    if (!inputColorIsUsed && !skipColor) {
        header->fColorInput = kAllOnes_ColorInput;
    } else if (defaultToUniformInputs && !requiresColorAttrib && inputColorIsUsed) {
        header->fColorInput = kUniform_ColorInput;
    } else {
        header->fColorInput = kAttribute_ColorInput;
        header->fRequiresVertexShader = true;
    }

    bool covIsSolidWhite = !requiresCoverageAttrib && 0xffffffff == drawState.getCoverageColor();

    if ((covIsSolidWhite || !inputCoverageIsUsed) && !skipCoverage) {
        header->fCoverageInput = kAllOnes_ColorInput;
    } else if (defaultToUniformInputs && !requiresCoverageAttrib && inputCoverageIsUsed) {
        header->fCoverageInput = kUniform_ColorInput;
    } else {
        header->fCoverageInput = kAttribute_ColorInput;
        header->fRequiresVertexShader = true;
    }

    if (readsDst) {
        SkASSERT(NULL != dstCopy || gpu->caps()->dstReadInShaderSupport());
        const GrTexture* dstCopyTexture = NULL;
        if (NULL != dstCopy) {
            dstCopyTexture = dstCopy->texture();
        }
        header->fDstReadKey = GrGLFragmentShaderBuilder::KeyForDstRead(dstCopyTexture,
                gpu->glCaps());
        SkASSERT(0 != header->fDstReadKey);
    } else {
        header->fDstReadKey = 0;
    }

    if (readFragPosition) {
        header->fFragPosKey = GrGLFragmentShaderBuilder::KeyForFragmentPosition(
                drawState.getRenderTarget(), gpu->glCaps());
    } else {
        header->fFragPosKey = 0;
    }

    // Record attribute indices
    header->fPositionAttributeIndex = drawState.positionAttributeIndex();