skia2/include/gpu/GrContextOptions.h

/*
 * Copyright 2015 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef GrContextOptions_DEFINED
#define GrContextOptions_DEFINED

#include "SkTypes.h"

struct GrContextOptions {
    GrContextOptions()
        : fSuppressPrints(false)
        , fMaxTextureSizeOverride(SK_MaxS32)
        , fMaxTileSizeOverride(0)
        , fSuppressDualSourceBlending(false)
        , fBufferMapThreshold(-1)
        , fUseDrawInsteadOfPartialRenderTargetWrite(false)
        , fImmediateMode(false)
        , fClipBatchToBounds(false)
        , fDrawBatchBounds(false)
        , fMaxBatchLookback(-1)
        , fMaxBatchLookahead(-1)
        , fUseShaderSwizzling(false)
        , fDoManualMipmapping(false)
        , fEnableInstancedRendering(false) {}

    // Suppress prints for the GrContext.
    bool fSuppressPrints;

    /** Overrides: These options override feature detection using backend API queries. These
        overrides can only reduce the feature set or limits, never increase them beyond the
        detected values. */

    int  fMaxTextureSizeOverride;
    /** If non-zero, overrides the maximum size of a tile for sw-backed images and bitmaps rendered
        by SkGpuDevice. */
    int  fMaxTileSizeOverride;
    bool fSuppressDualSourceBlending;

    /** the threshold in bytes above which we will use a buffer mapping API to map vertex and index
        buffers to CPU memory in order to update them.  A value of -1 means the GrContext should
        deduce the optimal value for this platform. */
    int  fBufferMapThreshold;

    /** some gpus have problems with partial writes of the rendertarget */
    bool fUseDrawInsteadOfPartialRenderTargetWrite;

    /** The GrContext operates in immediate mode. It will issue all draws to the backend API
        immediately. Intended to ease debugging. */
    bool fImmediateMode;

    /** For debugging purposes turn each GrBatch's bounds into a clip rect. This is used to
        verify that the clip bounds are conservative. */
    bool fClipBatchToBounds;

    /** For debugging purposes draw a wireframe device bounds rect for each GrBatch. The wire
        frame rect is draw before the GrBatch in order to visualize batches that draw outside
        of their dev bounds. */
    bool fDrawBatchBounds;

    /** For debugging, override the default maximum look-back or look-ahead window for GrBatch
        combining. */
    int fMaxBatchLookback;
    int fMaxBatchLookahead;

    /** Force us to do all swizzling manually in the shader and don't rely on extensions to do
        swizzling. */
    bool fUseShaderSwizzling;

    /** Construct mipmaps manually, via repeated downsampling draw-calls. This is used when
        the driver's implementation (glGenerateMipmap) contains bugs. This requires mipmap
        level and LOD control (ie desktop or ES3). */
    bool fDoManualMipmapping;

    /** Enable instanced rendering as long as all required functionality is supported by the HW.
        Instanced rendering is still experimental at this point and disabled by default. */
    bool fEnableInstancedRendering;
};

#endif