add an N-body vulkan sharing sample (#67)

* first working version

* simplified

* vulkan nbody runs with no validation errors and first frame output

* added one vertex buffer per swapchain image

* copies are working through the host

* external memory is working

* remove unneeded GLU dependency

* update GitHub actions checkout to v3

* added external memory and semaphore support

* minor dma_buf fixes

* add an option to require linear images

* add an OpenGL CMake default if one is not provided explicitly

* update READMEs

Author: bashbaug

.github/workflows/build.yml

@@ -15,7 +15,7 @@ jobs:
   check:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Check Tabs
       run: |
@@ -36,7 +36,7 @@ jobs:
     runs-on: ${{matrix.os}}
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Get Ubuntu OpenGL Dependencies
       if: matrix.os == 'ubuntu-latest'
@@ -45,20 +45,20 @@ jobs:
         sudo apt-get install -y libglfw3-dev
 
     - name: Get OpenCL Headers
-      uses: actions/checkout@main
+      uses: actions/checkout@v3
       with:
         repository: KhronosGroup/OpenCL-Headers
         path: external/OpenCL-Headers
 
     - name: Get OpenCL ICD Loader
-      uses: actions/checkout@main
+      uses: actions/checkout@v3
       with:
         repository: KhronosGroup/OpenCL-ICD-Loader
         path: external/opencl-icd-loader
 
     - name: Get OpenCL Extension Loader
       if: matrix.ext == 'YES'
-      uses: actions/checkout@master
+      uses: actions/checkout@v3
       with:
         repository: bashbaug/opencl-extension-loader
         path: external/opencl-extension-loader

samples/opengl/01_nbodygl/CMakeLists.txt

@@ -0,0 +1,28 @@
+# Copyright (c) 2022 Ben Ashbaugh
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+add_opencl_sample(
+    NUMBER 01
+    TARGET nbodygl
+    VERSION 120
+    CATEGORY opengl
+    SOURCES main.cpp
+    INCLUDES ${OPENGL_INCLUDE_DIRS}
+    LIBS ${OPENGL_LIBRARIES} glfw)

samples/opengl/01_nbodygl/README.md

@@ -0,0 +1,33 @@
+# N-Body Simulation with OpenGL
+
+## Sample Purpose
+
+This sample uses OpenCL to compute an [N-body simulation](https://en.wikipedia.org/wiki/N-body_simulation), which is then rendered with OpenGL.
+
+This sample currently does not share the OpenCL buffer with OpenGL and will unconditionally copy from OpenCL to OpenGL on the host.
+It is most useful as a reference for the similar Vulkan sample.
+
+## Key APIs and Concepts
+
+This example shows how to copy from an OpenCL buffer to OpenGL.
+
+## Command Line Options
+
+| Option | Default Value | Description |
+|:--|:-:|:--|
+| `-d <index>` | 0 | Specify the index of the OpenCL device in the platform to execute on the sample on.
+| `-p <index>` | 0 | Specify the index of the OpenCL platform to execute the sample on.
+| `-n` | 1024 | Specify the number of bodies to simulate.
+| `-g` | 0| Specify the local work size.  If the local works size is zero a `NULL` local work size is used.
+| `-w` | 1024 | Specify the render width in pixels.
+| `-h` | 1024 | Specify the render height in pixels.
+
+## Controls While Running
+
+| Control | Description |
+|:--|:--|
+| `Escape` | Exits from the sample.
+| `Space` | Toggle animation (default: `false`).
+| `S` | Single-step the simulation.
+| `R` | Re-initialize the simulation.
+| `V` | Toggle vsync (default: `true`). Disabling vsync may increase framerate but may cause [screen tearing](https://en.wikipedia.org/wiki/Screen_tearing).