C++ (Cpp) PremultipliedImage::stride Examples

Example #1

File: headless_view.cpp Project: PaulZed/mapbox-gl-native

PremultipliedImage HeadlessView::readStillImage() {
    assert(active);

    const unsigned int w = dimensions[0] * pixelRatio;
    const unsigned int h = dimensions[1] * pixelRatio;

    PremultipliedImage image { w, h };
    MBGL_CHECK_ERROR(glReadPixels(0, 0, w, h, GL_RGBA, GL_UNSIGNED_BYTE, image.data.get()));

    const auto stride = image.stride();
    auto tmp = std::make_unique<uint8_t[]>(stride);
    uint8_t* rgba = image.data.get();
    for (int i = 0, j = h - 1; i < j; i++, j--) {
        std::memcpy(tmp.get(), rgba + i * stride, stride);
        std::memcpy(rgba + i * stride, rgba + j * stride, stride);
        std::memcpy(rgba + j * stride, tmp.get(), stride);
    }

    return image;
}

Example #2

File: headless_view.cpp Project: OrdnanceSurvey/mapbox-gl-native

PremultipliedImage HeadlessView::readStillImage(std::array<uint16_t, 2> size) {
    assert(active);

    if (!size[0] || !size[1]) {
        size[0] = dimensions[0] * pixelRatio;
        size[1] = dimensions[1] * pixelRatio;
    }

    PremultipliedImage image { size[0], size[1] };
    MBGL_CHECK_ERROR(glReadPixels(0, 0, size[0], size[1], GL_RGBA, GL_UNSIGNED_BYTE, image.data.get()));

    const auto stride = image.stride();
    auto tmp = std::make_unique<uint8_t[]>(stride);
    uint8_t* rgba = image.data.get();
    for (int i = 0, j = size[1] - 1; i < j; i++, j--) {
        std::memcpy(tmp.get(), rgba + i * stride, stride);
        std::memcpy(rgba + i * stride, rgba + j * stride, stride);
        std::memcpy(rgba + j * stride, tmp.get(), stride);
    }

    return image;
}