Port of the iconic gears demo to GLSL and the Vulkan API using GLFW.
The gears demo remains a good test of basic display driver functionality during driver bring up, making it a useful test program. There is more complexity than the Vulkan triangle demo due to the use of vertex buffers and uniform buffers. It is a good, simple, complete and stand-alone example.
src/gl1_gears.c- original GLFW port of the public domain gears demo.src/gl2_gears.c- OpenGL 2.1 port of the public domain gears demo.src/gl3_gears.c- OpenGL 3.2 port of the public domain gears demo.src/gl4_gears.c- OpenGL 4.5 port of the public domain gears demo.src/vk1_gears.c- Vulkan 1.1 port of the public domain gears demo.src/linmath.h- public domain linear algebra header functions.src/gl2_util.h- header functions for OpenGL ES2 buffers and shaders.
The project includes several versions of gears ported to multiple APIs.
gl1_gears is the OpenGL 1.x port of gears using immediate mode vertices, call lists and the fixed function lighting model. This code is derived from the gears port included with GLFW.
gl2_gears is the OpenGL 2.x port of gears using GLSL shaders.
It has been ported to use Wolfgang Draxinger's "linmath.h" mat4x4
for constructing the model, view and projection matrices. "gl2_util.h"
contains shader loading and a simple vertex and index buffer implementation.
gl3_gears is like gl2_gears with the addition of vertex array objects which were added in OpenGL 3.x.
gl4_gears is like gl3_gears with the addition of uniform buffer objects and SPIR-V binary shaders which were added in OpenGL 4.x.
vk1_gears is the Vulkan 1.1 port of gears using SPIR-V shaders.
It also uses Wolfgang Draxinger's "linmath.h" mat4x4. vk1_gears
uses the same vertex and index buffer creation code as gl2_gears.
The Vulkan port also takes several command line options to select display size, sample buffers and to enable Vulkan validation or API dump layers.
$ vk1_gears -help
usage: ./build/vk1_gears [options]
Options
-max-swapchain-images <int> specify max-swapchain-images
-max-samples <int> specify max-samples
-[no-]api-dump enable or disable api-dump
-[no-]validation enable or disable validation
-[no-]multisampling enable or disable multisampling
-[no-]animation enable or disable animation
-[no-]verbose enable or disable verbose
-width <int> specify width
-height <int> specify height
-help <int> specify help