Merge "Properly convert A8 -> RGBA_8888 gainmap contents" into main

 */

#include "Gainmap.h"

#include <SkBitmap.h>

#include <SkCanvas.h>

#include <SkColorFilter.h>

#include <SkImagePriv.h>

#include <SkPaint.h>

#include "HardwareBitmapUploader.h"

namespace android::uirenderer {

sp<Gainmap> Gainmap::allocateHardwareGainmap(const sp<Gainmap>& srcGainmap) {

    auto gainmap = sp<Gainmap>::make();

    gainmap->info = srcGainmap->info;

    const SkBitmap skSrcBitmap = srcGainmap->bitmap->getSkBitmap();

    SkBitmap skSrcBitmap = srcGainmap->bitmap->getSkBitmap();

    if (skSrcBitmap.info().colorType() == kAlpha_8_SkColorType &&

        !HardwareBitmapUploader::hasAlpha8Support()) {

        // The regular Bitmap::allocateHardwareBitmap will do a conversion that preserves channels,

        // so alpha8 maps to the alpha channel of rgba. However, for gainmaps we will interpret

        // the data of an rgba buffer differently as we'll only look at the rgb channels

        // So we need to map alpha8 to rgbx_8888 essentially

        SkBitmap bitmap;

        bitmap.allocPixels(skSrcBitmap.info().makeColorType(kN32_SkColorType));

        SkCanvas canvas(bitmap);

        SkPaint paint;

        const float alphaToOpaque[] = {0, 0, 0, 1, 0, 0, 0, 0, 1, 0,

                                       0, 0, 0, 1, 0, 0, 0, 0, 0, 255};

        paint.setColorFilter(SkColorFilters::Matrix(alphaToOpaque, SkColorFilters::Clamp::kNo));

        canvas.drawImage(SkMakeImageFromRasterBitmap(skSrcBitmap, kNever_SkCopyPixelsMode), 0, 0,

                         SkSamplingOptions{}, &paint);

        skSrcBitmap = bitmap;

    }

    sk_sp<Bitmap> skBitmap(Bitmap::allocateHardwareBitmap(skSrcBitmap));

    if (!skBitmap.get()) {

        return nullptr;