diff options
| -rw-r--r-- | package.json | 2 | ||||
| -rw-r--r-- | platform/default/headless_view.cpp | 36 |
2 files changed, 28 insertions, 10 deletions
diff --git a/package.json b/package.json index ad8bbb8fde..e21e7f7691 100644 --- a/package.json +++ b/package.json @@ -1,6 +1,6 @@ { "name": "mapbox-gl-native", - "version": "2.2.0", + "version": "2.2.0-pbo", "description": "Renders map tiles with Mapbox GL", "keywords": [ "mapbox", diff --git a/platform/default/headless_view.cpp b/platform/default/headless_view.cpp index 7fd3c37f3a..dda2f6ca3d 100644 --- a/platform/default/headless_view.cpp +++ b/platform/default/headless_view.cpp @@ -176,17 +176,35 @@ PremultipliedImage HeadlessView::readStillImage() { 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 int 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); + GLuint bufferId; + + MBGL_CHECK_ERROR(glGenBuffers(1, &bufferId)); + MBGL_CHECK_ERROR(glBindBuffer(GL_PIXEL_PACK_BUFFER, bufferId)); + MBGL_CHECK_ERROR(glBufferData(GL_PIXEL_PACK_BUFFER, h * image.stride(), 0, GL_STREAM_READ)); + MBGL_CHECK_ERROR(glReadPixels(0, 0, w, h, GL_RGBA, GL_UNSIGNED_BYTE, 0)); + + // map the PBO to process its data by CPU + GLubyte* ptr = (GLubyte*)glMapBuffer(GL_PIXEL_PACK_BUFFER, GL_READ_ONLY); + + if (ptr) { + const int stride = image.stride(); + auto tmp = std::make_unique<uint8_t[]>(stride); + uint8_t* rgba = image.data.get(); + + for (unsigned int i = 0, j = h - 1; i < h; i++, j--) { + std::memcpy(rgba + i * stride, ptr + j * stride, stride); + } + + MBGL_CHECK_ERROR(glUnmapBuffer(GL_PIXEL_PACK_BUFFER)); + } else { + throw std::runtime_error(std::string("Could not map buffer on return from read pixels.")); } + MBGL_CHECK_ERROR(glDeleteBuffers(1, &bufferId)); + + // back to conventional pixel operation + MBGL_CHECK_ERROR(glBindBuffer(GL_PIXEL_PACK_BUFFER, 0)); + return image; } |