Post-merge TODO

  • Additional transform feedback functionality (GL_ARB_transform_feedback2, GL_ARB_transform_feedback3)
    • stream buffers (GL_ARB_transform_feedback3) presents several problems:
      1. not a single good example on the web (g-truc samples only use a single stream!)
      2. since each stream buffer can have a different vertex count, it is unclear how feedback works - presumably only a single stream buffer can be used as input into a vertex shader, so perhaps the use case is to feed each stream to a different vertex shader that takes in only those particular variables.
      3. requires that individual output stream data formats be specified via RenderingToVertexBuffer, in addition to the already cumbersome specification of the input vertex buffer data formatting.
    • so the new rendering to vertex buffer API is:
      1. specify input vertex buffer data format and each output stream buffer data format. If no output buffers are specified, assume single output stream buffer with same format as input.
      2. somehow specify output passes so that each stream buffer can be directed to its respective pass (may be the same transform feedback pass, a different transform to feedback pass, a regular rasterization pass, etc.)
    • The ideal solution is to abstract function composition in OGRE so that screen composition (render to fragment texture) and vertex composition (rendering to vertex buffer) use the same API and compositor scripts.
  • SDL2
    1. SDL window support (via CMake)
    2. windowing plugin system
    3. SampleBrowser input
  • Provide the ability for OpenGL shaders to perform random access reads, writes, and atomic memory operations on variables stored in a buffer object (ARB_shader_storage_buffer_object)
  • Support for “indirect subroutine calls”, where a single shader can include many subroutines and dynamically select through the API which subroutine is called from each call site (GL_ARB_shader_subroutine)
  • Cube map array textures, 2-dimensional array textures that may contain many cube map layers. Each cube map layer is a unique cube map image set (GL_ARB_texture_cube_map_array)
  • Multisampled textures and texture samplers for specific sample locations (GL_ARB_texture_multisample)
  • ensure image load/store and atomic counters still work
  • add any necessary material transforms for this project
  • update OGRE tutorial framework to be completely shader based, using as little or no RTSS

GL4 TODO

GL4 Rendering Pipeline

  • Render many draws using MultiDrawIndirect (see previous discussion). (GL_ARB_multi_draw_indirect)
    • Figure out efficient way to bin draws with same API state (same bindings, depth test, blend function, etc.).
    • Means to index draw data per-draw (and per-vertex if buffers used for vertex data).
    • Store uniform (and possibly vertex) data in uniform or shader storage buffers.
    • Store textures using bindless textures in the above uniform blocks. (GL_ARB_bindless_texture)
    • Look into whether depth test and blend function states change often in practice and if they can be efficiently binned.
    • Require über-shaders since shaders cannot be changed in the same multidraw. Use shader subroutines or switches to take different material paths. Suggest splitting radically different shaders up and binning draws accordingly.
    • Either require all vertex data of a given call to be in the same format or request users with mixed formats to stick to shader storage buffers for passing vertex data.
    • All vertex indices need to be in one buffer for entire sequence of draws handled by MultiDrawElementsIndirect.
  • Traverse scene graph using multi-thread CPU, compute shader or transform feedback to create draw calls for MultiDrawIndirect.


OpenGL 4.4 features

  • add GL 4.4 features to transform feedback, particularly shader specified feedback variables
  • possibly restore material support for transform feedback if 4.4 adoption is slow (transform block within material pass listing feedback variable names and types)

GL3+ TODO

  • port EGL window system from GLES RS



Samples

  • compositor
  • deferred shading (may be fixed upstream)
  • dual quaternion skinning (RTSS issues)
  • endless terrain (complex problems)
  • facial animation
  • grass (cg material mistakenly being selected)
  • mesh LOD (Athena needs texture - probably wait until after GSOC merge)
  • PN triangles (needs implementing)
  • particle effects (aureola effect does not look right)
  • shader system (easy & hard fixes)
  • shader system - textured fog (background not initially set, lighting might need to be added?)
  • shader system - multi light (lighting has bars going through it)
  • shadows (seriously borked)
  • sky box (corners of box show white)
  • sky dome (fish textures missing or black)
  • sky plane (dragon wings visible on one side, not the other)
  • terrain (sky does not appear correctly, possible lighting/shadows problem)
  • volume csg (texture is missing)
  • volume terrain (lighting and triplanar texturing broken - seems that normals are not correctly passed to shader)
  • volume textures (was working, now a mess of fog with floating white rectangles and a combed square)
  • water (water 0, 3, 4 thoroughly borked)

Visual Tests (GL & GL3+) - see original reference images and recent reference images

  • TODO create new list prior to merge


NEW Visual Tests

  • tessellation (port tessellation sample to visual test, then replace sample with something cool)
  • transform feedback (render to vertex buffer)
  • shader storage block + uniform block
  • atomic counters
  • compute shader
  • image load/store
  • and more...


Documentation

  • add note in Visual Unit Testing Framework about nograb option causing results to be non-deterministic
  • transform feedback currently requires feedback variables to be named oPos for position, oUvX for X texture index, and so on


Known Bugs

  • Examples/Aureola from the billboard particle system sample originally used PF_BYTE_LA (grayscale luminance alpha) format which requires a byte per channel, but FreeImage read the file as 32 bpp implying that either the file needs to be converted to 16 bpp (8 bit per channel, with channels being luminance & alpha) or FreeImage has a bug. Since GIMP reports the PNG image as grayscale transparent, I am inclined to think this is a FreeImage bug, crazy as that sounds.

Bonus GL3+ Goals

This is a list of problems I would like to solve during my GSoC, but may not get around to until afterwards.

General

  • General code review needs to be done
  • Unify redundant mappings (OGRE type to string, GL type to string, GL type to OGRE type, visa versa, etc.)
  • Investigate effect on driver serialization (shim + server flush and sync) of glGet(...), glGetError, functions that return a value, and functions that copy a non-determinable amount of client memory (see slides 50-51 of NVIDIA/Valve porting to Linux talk).
  • See if GL3+ render engine is making any of the common mistakes.
  • rename Tesselation -> Tessellation throughout Ogre
  • add material script support for uniform arrays (of the form int5, float8, etc.) in ScriptTranslator so that you can write int5 1 2 3 4 5
  • add material script support for bool and uint in shared_param_named
  • ensure GL command cache is merged (pull request)

Samples

  • Add some form of exception handling to Ogre string utility library (discuss cost/benefit of alternative means, use profiling)
  • Grass - determine why GL and GL3+ fall back on the plain texture technique when perfectly fine techniques are available in the material script

Visual Tests

  • BSP - To fix BSP vtest, it must be moved from PlayPen to VTest or else RTSS needs to be setup in PlayPen. Alternatively, however non-RTSS BSP shaders are constructed could be fixed. It is looking for textures in the wrong places within the PK3 archive. Currently only RTSS created shaders correctly locate the texture files.
  • Distortion - upgrade material parser to determine when asm passes are ARB or DirectX when determining if a technique is supported; see Ogre::Technique::checkHardwareSupport. Best means is adding an 'arb' format and assuming 'asm' is DirectX assembly. When this is done, re-enable old technique in Examples/FresnelReflectionRefraction
  • add additional debugging messages and create interface for markers and groups for khr_debug

General TODO

  • Make BaseApplication use shaders
  • General SWIG wrapper (for Python, Go, D, C#, etc.)
  • Allow per-entity uniforms in material manager (see previous discussion)
  • Document GL3+ and GSoC features using Doxygen and OGRE manual

Community TODO

  • Add texi2html OGRE manual generation to CMakeLists
  • Fix the second tutorial to mention proper resource usage!
person wrote:

The 'dist' directory is only a sample.
It contains the minimum you need to make use of the sdk trays GUI and to load the Ogre head.
If you need more, you need to add it yourself. :-)

However, maybe it would be a good idea to add a note to the tutorial in question explaining how to add the Ninja to the 'dist'.
I'll put that on a todo.


<HR>
Creative Commons Copyright -- Some rights reserved.


THE WORK (AS DEFINED BELOW) IS PROVIDED UNDER THE TERMS OF THIS CREATIVE COMMONS PUBLIC LICENSE ("CCPL" OR "LICENSE"). THE WORK IS PROTECTED BY COPYRIGHT AND/OR OTHER APPLICABLE LAW. ANY USE OF THE WORK OTHER THAN AS AUTHORIZED UNDER THIS LICENSE OR COPYRIGHT LAW IS PROHIBITED.

BY EXERCISING ANY RIGHTS TO THE WORK PROVIDED HERE, YOU ACCEPT AND AGREE TO BE BOUND BY THE TERMS OF THIS LICENSE. THE LICENSOR GRANTS YOU THE RIGHTS CONTAINED HERE IN CONSIDERATION OF YOUR ACCEPTANCE OF SUCH TERMS AND CONDITIONS.

1. Definitions

  • "Collective Work" means a work, such as a periodical issue, anthology or encyclopedia, in which the Work in its entirety in unmodified form, along with a number of other contributions, constituting separate and independent works in themselves, are assembled into a collective whole. A work that constitutes a Collective Work will not be considered a Derivative Work (as defined below) for the purposes of this License.
  • "Derivative Work" means a work based upon the Work or upon the Work and other pre-existing works, such as a translation, musical arrangement, dramatization, fictionalization, motion picture version, sound recording, art reproduction, abridgment, condensation, or any other form in which the Work may be recast, transformed, or adapted, except that a work that constitutes a Collective Work will not be considered a Derivative Work for the purpose of this License. For the avoidance of doubt, where the Work is a musical composition or sound recording, the synchronization of the Work in timed-relation with a moving image ("synching") will be considered a Derivative Work for the purpose of this License.
  • "Licensor" means the individual or entity that offers the Work under the terms of this License.
  • "Original Author" means the individual or entity who created the Work.
  • "Work" means the copyrightable work of authorship offered under the terms of this License.
  • "You" means an individual or entity exercising rights under this License who has not previously violated the terms of this License with respect to the Work, or who has received express permission from the Licensor to exercise rights under this License despite a previous violation.
  • "License Elements" means the following high-level license attributes as selected by Licensor and indicated in the title of this License: Attribution, ShareAlike.

2. Fair Use Rights

Nothing in this license is intended to reduce, limit, or restrict any rights arising from fair use, first sale or other limitations on the exclusive rights of the copyright owner under copyright law or other applicable laws.

3. License Grant

Subject to the terms and conditions of this License, Licensor hereby grants You a worldwide, royalty-free, non-exclusive, perpetual (for the duration of the applicable copyright) license to exercise the rights in the Work as stated below:

  • to reproduce the Work, to incorporate the Work into one or more Collective Works, and to reproduce the Work as incorporated in the Collective Works;
  • to create and reproduce Derivative Works;
  • to distribute copies or phonorecords of, display publicly, perform publicly, and perform publicly by means of a digital audio transmission the Work including as incorporated in Collective Works;
  • to distribute copies or phonorecords of, display publicly, perform publicly, and perform publicly by means of a digital audio transmission Derivative Works.
  • For the avoidance of doubt, where the work is a musical composition:
    • Performance Royalties Under Blanket Licenses. Licensor waives the exclusive right to collect, whether individually or via a performance rights society (e.g. ASCAP, BMI, SESAC), royalties for the public performance or public digital performance (e.g. webcast) of the Work.
    • Mechanical Rights and Statutory Royalties. Licensor waives the exclusive right to collect, whether individually or via a music rights society or designated agent (e.g. Harry Fox Agency), royalties for any phonorecord You create from the Work ("cover version") and distribute, subject to the compulsory license created by 17 USC Section 115 of the US Copyright Act (or the equivalent in other jurisdictions).
    • Webcasting Rights and Statutory Royalties. For the avoidance of doubt, where the Work is a sound recording, Licensor waives the exclusive right to collect, whether individually or via a performance-rights society (e.g. SoundExchange), royalties for the public digital performance (e.g. webcast) of the Work, subject to the compulsory license created by 17 USC Section 114 of the US Copyright Act (or the equivalent in other jurisdictions).


The above rights may be exercised in all media and formats whether now known or hereafter devised. The above rights include the right to make such modifications as are technically necessary to exercise the rights in other media and formats. All rights not expressly granted by Licensor are hereby reserved.

4. Restrictions

The license granted in Section 3 above is expressly made subject to and limited by the following restrictions:

  • You may distribute, publicly display, publicly perform, or publicly digitally perform the Work only under the terms of this License, and You must include a copy of, or the Uniform Resource Identifier for, this License with every copy or phonorecord of the Work You distribute, publicly display, publicly perform, or publicly digitally perform. You may not offer or impose any terms on the Work that alter or restrict the terms of this License or the recipients' exercise of the rights granted hereunder. You may not sublicense the Work. You must keep intact all notices that refer to this License and to the disclaimer of warranties. You may not distribute, publicly display, publicly perform, or publicly digitally perform the Work with any technological measures that control access or use of the Work in a manner inconsistent with the terms of this License Agreement. The above applies to the Work as incorporated in a Collective Work, but this does not require the Collective Work apart from the Work itself to be made subject to the terms of this License. If You create a Collective Work, upon notice from any Licensor You must, to the extent practicable, remove from the Collective Work any credit as required by clause 4(c), as requested. If You create a Derivative Work, upon notice from any Licensor You must, to the extent practicable, remove from the Derivative Work any credit as required by clause 4(c), as requested.
  • You may distribute, publicly display, publicly perform, or publicly digitally perform a Derivative Work only under the terms of this License, a later version of this License with the same License Elements as this License, or a Creative Commons iCommons license that contains the same License Elements as this License (e.g. Attribution-ShareAlike 2.5 Japan). You must include a copy of, or the Uniform Resource Identifier for, this License or other license specified in the previous sentence with every copy or phonorecord of each Derivative Work You distribute, publicly display, publicly perform, or publicly digitally perform. You may not offer or impose any terms on the Derivative Works that alter or restrict the terms of this License or the recipients' exercise of the rights granted hereunder, and You must keep intact all notices that refer to this License and to the disclaimer of warranties. You may not distribute, publicly display, publicly perform, or publicly digitally perform the Derivative Work with any technological measures that control access or use of the Work in a manner inconsistent with the terms of this License Agreement. The above applies to the Derivative Work as incorporated in a Collective Work, but this does not require the Collective Work apart from the Derivative Work itself to be made subject to the terms of this License.
  • If you distribute, publicly display, publicly perform, or publicly digitally perform the Work or any Derivative Works or Collective Works, You must keep intact all copyright notices for the Work and provide, reasonable to the medium or means You are utilizing: (i) the name of the Original Author (or pseudonym, if applicable) if supplied, and/or (ii) if the Original Author and/or Licensor designate another party or parties (e.g. a sponsor institute, publishing entity, journal) for attribution in Licensor's copyright notice, terms of service or by other reasonable means, the name of such party or parties; the title of the Work if supplied; to the extent reasonably practicable, the Uniform Resource Identifier, if any, that Licensor specifies to be associated with the Work, unless such URI does not refer to the copyright notice or licensing information for the Work; and in the case of a Derivative Work, a credit identifying the use of the Work in the Derivative Work (e.g., "French translation of the Work by Original Author," or "Screenplay based on original Work by Original Author"). Such credit may be implemented in any reasonable manner; provided, however, that in the case of a Derivative Work or Collective Work, at a minimum such credit will appear where any other comparable authorship credit appears and in a manner at least as prominent as such other comparable authorship credit.

5. Representations, Warranties and Disclaimer

UNLESS OTHERWISE AGREED TO BY THE PARTIES IN WRITING, LICENSOR OFFERS THE WORK AS-IS AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND CONCERNING THE MATERIALS, EXPRESS, IMPLIED, STATUTORY OR OTHERWISE, INCLUDING, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTIBILITY, FITNESS FOR A PARTICULAR PURPOSE, NONINFRINGEMENT, OR THE ABSENCE OF LATENT OR OTHER DEFECTS, ACCURACY, OR THE PRESENCE OF ABSENCE OF ERRORS, WHETHER OR NOT DISCOVERABLE. SOME JURISDICTIONS DO NOT ALLOW THE EXCLUSION OF IMPLIED WARRANTIES, SO SUCH EXCLUSION MAY NOT APPLY TO YOU.

6. Limitation on Liability.

EXCEPT TO THE EXTENT REQUIRED BY APPLICABLE LAW, IN NO EVENT WILL LICENSOR BE LIABLE TO YOU ON ANY LEGAL THEORY FOR ANY SPECIAL, INCIDENTAL, CONSEQUENTIAL, PUNITIVE OR EXEMPLARY DAMAGES ARISING OUT OF THIS LICENSE OR THE USE OF THE WORK, EVEN IF LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

7. Termination

  • This License and the rights granted hereunder will terminate automatically upon any breach by You of the terms of this License. Individuals or entities who have received Derivative Works or Collective Works from You under this License, however, will not have their licenses terminated provided such individuals or entities remain in full compliance with those licenses. Sections 1, 2, 5, 6, 7, and 8 will survive any termination of this License.
  • Subject to the above terms and conditions, the license granted here is perpetual (for the duration of the applicable copyright in the Work). Notwithstanding the above, Licensor reserves the right to release the Work under different license terms or to stop distributing the Work at any time; provided, however that any such election will not serve to withdraw this License (or any other license that has been, or is required to be, granted under the terms of this License), and this License will continue in full force and effect unless terminated as stated above.

8. Miscellaneous

  • Each time You distribute or publicly digitally perform the Work or a Collective Work, the Licensor offers to the recipient a license to the Work on the same terms and conditions as the license granted to You under this License.
  • Each time You distribute or publicly digitally perform a Derivative Work, Licensor offers to the recipient a license to the original Work on the same terms and conditions as the license granted to You under this License.
  • If any provision of this License is invalid or unenforceable under applicable law, it shall not affect the validity or enforceability of the remainder of the terms of this License, and without further action by the parties to this agreement, such provision shall be reformed to the minimum extent necessary to make such provision valid and enforceable.
  • No term or provision of this License shall be deemed waived and no breach consented to unless such waiver or consent shall be in writing and signed by the party to be charged with such waiver or consent.
  • This License constitutes the entire agreement between the parties with respect to the Work licensed here. There are no understandings, agreements or representations with respect to the Work not specified here. Licensor shall not be bound by any additional provisions that may appear in any communication from You. This License may not be modified without the mutual written agreement of the Licensor and You.