src/gpu/GrDrawState.cpp

/*
 * Copyright 2012 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "GrDrawState.h"

#include "GrPaint.h"

void GrDrawState::setFromPaint(const GrPaint& paint) {
    for (int i = 0; i < GrPaint::kMaxColorStages; ++i) {
        int s = i + GrPaint::kFirstColorStage;
        if (paint.isColorStageEnabled(i)) {
            fStages[s] = paint.getColorStage(i);
        } else {
            fStages[s].setEffect(NULL);
        }
    }

    this->setFirstCoverageStage(GrPaint::kFirstCoverageStage);

    for (int i = 0; i < GrPaint::kMaxCoverageStages; ++i) {
        int s = i + GrPaint::kFirstCoverageStage;
        if (paint.isCoverageStageEnabled(i)) {
            fStages[s] = paint.getCoverageStage(i);
        } else {
            fStages[s].setEffect(NULL);
        }
    }

    // disable all stages not accessible via the paint
    for (int s = GrPaint::kTotalStages; s < GrDrawState::kNumStages; ++s) {
        this->disableStage(s);
    }

    this->setColor(paint.getColor());

    this->setState(GrDrawState::kDither_StateBit, paint.isDither());
    this->setState(GrDrawState::kHWAntialias_StateBit, paint.isAntiAlias());

    this->setBlendFunc(paint.getSrcBlendCoeff(), paint.getDstBlendCoeff());
    this->setColorFilter(paint.getColorFilterColor(), paint.getColorFilterMode());
    this->setCoverage(paint.getCoverage());
}

////////////////////////////////////////////////////////////////////////////////

void GrDrawState::AutoViewMatrixRestore::restore() {
    if (NULL != fDrawState) {
        fDrawState->setViewMatrix(fViewMatrix);
        for (int s = 0; s < GrDrawState::kNumStages; ++s) {
            if (fRestoreMask & (1 << s)) {
                fDrawState->fStages[s].restoreCoordChange(fSavedCoordChanges[s]);
            }
        }
    }
    fDrawState = NULL;
}

void GrDrawState::AutoViewMatrixRestore::set(GrDrawState* drawState,
                                             const SkMatrix& preconcatMatrix,
                                             uint32_t explicitCoordStageMask) {
    this->restore();

    fDrawState = drawState;
    if (NULL == drawState) {
        return;
    }

    fRestoreMask = 0;
    fViewMatrix = drawState->getViewMatrix();
    drawState->preConcatViewMatrix(preconcatMatrix);
    for (int s = 0; s < GrDrawState::kNumStages; ++s) {
        if (!(explicitCoordStageMask & (1 << s)) && drawState->isStageEnabled(s)) {
            fRestoreMask |= (1 << s);
            fDrawState->fStages[s].saveCoordChange(&fSavedCoordChanges[s]);
            drawState->fStages[s].preConcatCoordChange(preconcatMatrix);
        }
    }
}

////////////////////////////////////////////////////////////////////////////////

void GrDrawState::AutoDeviceCoordDraw::restore() {
    if (NULL != fDrawState) {
        fDrawState->setViewMatrix(fViewMatrix);
        for (int s = 0; s < GrDrawState::kNumStages; ++s) {
            if (fRestoreMask & (1 << s)) {
                fDrawState->fStages[s].restoreCoordChange(fSavedCoordChanges[s]);
            }
        }
    }
    fDrawState = NULL;
}

bool GrDrawState::AutoDeviceCoordDraw::set(GrDrawState* drawState,
                                           uint32_t explicitCoordStageMask) {
    GrAssert(NULL != drawState);

    this->restore();

    fDrawState = drawState;
    if (NULL == fDrawState) {
        return false;
    }

    fViewMatrix = drawState->getViewMatrix();
    fRestoreMask = 0;
    SkMatrix invVM;
    bool inverted = false;

    for (int s = 0; s < GrDrawState::kNumStages; ++s) {
        if (!(explicitCoordStageMask & (1 << s)) && drawState->isStageEnabled(s)) {
            if (!inverted && !fViewMatrix.invert(&invVM)) {
                // sad trombone sound
                fDrawState = NULL;
                return false;
            } else {
                inverted = true;
            }
            fRestoreMask |= (1 << s);
            GrEffectStage* stage = drawState->fStages + s;
            stage->saveCoordChange(&fSavedCoordChanges[s]);
            stage->preConcatCoordChange(invVM);
        }
    }
    drawState->viewMatrix()->reset();
    return true;
}