This series is the continuation for the RFC that I posted earlier [1]
[1] RFC: https://patchwork.freedesktop.org/series/73884/
Integer scaling (IS) is a nearest-neighbor upscaling technique that simply scales up the existing pixels by an integer (i.e., whole number) multiplier. Nearest-neighbor (NN) interpolation works by filling in the missing color values in the upscaled image with that of the coordinate-mapped nearest source pixel value.
Both IS and NN preserve the clarity of the original image. In contrast, traditional upscaling algorithms, such as bilinear or bicubic interpolation, result in blurry upscaled images because they employ interpolation techniques that smooth out the transition from one pixel to another. Therefore, integer scaling is particularly useful for pixel art games that rely on sharp, blocky images to deliver their distinctive look.
Many gaming communities have been asking for integer-mode scaling support, some links and background:
https://software.intel.com/en-us/articles/integer-scaling-support-on-intel-g... http://tanalin.com/en/articles/lossless-scaling/ https://community.amd.com/thread/209107 https://www.nvidia.com/en-us/geforce/forums/game-ready-drivers/13/1002/featu...
This patch series - - Introduces new scaling filter properties to allow userspace to select the driver's default scaling filter or Nearest-neighbor(NN) filter for scaling operations on crtc and plane. - Implements and enable integer scaling for i915
Userspace patch series link: https://github.com/lrusak/xbmc/pull/24
Thanks to Shashank for initiating this work. His initial work can be found here [2]
[2] https://patchwork.freedesktop.org/patch/337082/
changes since v1: * Add userspace patch link to this cover letter. * 4/5 - Rearrange skl_scaler_setup_nearest_neighbor_filter() to iterate the registers directly instead of the phases and taps (Ville)
Pankaj Bharadiya (5): drm: Introduce plane and CRTC scaling filter properties drm/drm-kms.rst: Add plane and CRTC scaling filter property documentation drm/i915: Introduce scaling filter related registers and bit fields. drm/i915/display: Add Nearest-neighbor based integer scaling support drm/i915: Enable scaling filter for plane and CRTC
Documentation/gpu/drm-kms.rst | 12 +++ drivers/gpu/drm/drm_atomic_uapi.c | 8 ++ drivers/gpu/drm/drm_crtc.c | 33 ++++++ drivers/gpu/drm/drm_mode_config.c | 26 +++++ drivers/gpu/drm/drm_plane.c | 33 ++++++ drivers/gpu/drm/i915/display/intel_display.c | 104 ++++++++++++++++++- drivers/gpu/drm/i915/display/intel_display.h | 2 + drivers/gpu/drm/i915/display/intel_sprite.c | 31 +++++- drivers/gpu/drm/i915/i915_reg.h | 48 +++++++++ include/drm/drm_crtc.h | 13 +++ include/drm/drm_mode_config.h | 12 +++ include/drm/drm_plane.h | 13 +++ 12 files changed, 332 insertions(+), 3 deletions(-)