This repository has been archived on 2023-10-09. You can view files and clone it. You cannot open issues or pull requests or push a commit.
Files
blender-archive/source/blender/gpu/vulkan/vk_backend.cc
Jeroen Bakker 61b457d390 Vulkan: Push constants
**What are push constants?**

Push constants is a way to quickly provide a small amount of uniform data to shaders.
It should be much quicker than UBOs but a huge limitation is the size of data - spec
requires 128 bytes to be available for a push constant range.

**What are the challenges with push constants?**

The challenge with push constants is that the limited available size. According to
the Vulkan spec each platform should at least have 128 bytes reserved for push
constants. Current Mesa/AMD drivers supports 256 bytes, but Mesa/Intel is only 128
bytes.

**What is our solution?**

Some shaders of Blender uses more than these boundaries. When more data is needed
push constants will not be used, but the shader will be patched to use an uniform
buffer instead. This mechanism will be part of the Vulkan backend and shader
developers should not see any difference on API level.

**Known limitations**

Current state of the vulkan backend does not track resources that are in the
command queue. This patch includes some test cases that identified this issue as
well. See #104771.

Pull Request #104880
2023-03-06 12:28:55 +01:00

175 lines
3.6 KiB
C++

/* SPDX-License-Identifier: GPL-2.0-or-later
* Copyright 2022 Blender Foundation. All rights reserved. */
/** \file
* \ingroup gpu
*/
#include "gpu_capabilities_private.hh"
#include "gpu_platform_private.hh"
#include "vk_batch.hh"
#include "vk_context.hh"
#include "vk_drawlist.hh"
#include "vk_fence.hh"
#include "vk_framebuffer.hh"
#include "vk_index_buffer.hh"
#include "vk_pixel_buffer.hh"
#include "vk_query.hh"
#include "vk_shader.hh"
#include "vk_storage_buffer.hh"
#include "vk_texture.hh"
#include "vk_uniform_buffer.hh"
#include "vk_vertex_buffer.hh"
#include "vk_backend.hh"
namespace blender::gpu {
void VKBackend::init_platform()
{
BLI_assert(!GPG.initialized);
eGPUDeviceType device = GPU_DEVICE_ANY;
eGPUOSType os = GPU_OS_ANY;
eGPUDriverType driver = GPU_DRIVER_ANY;
eGPUSupportLevel support_level = GPU_SUPPORT_LEVEL_SUPPORTED;
#ifdef _WIN32
os = GPU_OS_WIN;
#elif defined(__APPLE__)
os = GPU_OS_MAC;
#else
os = GPU_OS_UNIX;
#endif
GPG.init(device, os, driver, support_level, GPU_BACKEND_VULKAN, "", "", "");
}
void VKBackend::platform_exit()
{
BLI_assert(GPG.initialized);
GPG.clear();
}
void VKBackend::delete_resources()
{
}
void VKBackend::samplers_update()
{
}
void VKBackend::compute_dispatch(int groups_x_len, int groups_y_len, int groups_z_len)
{
VKContext &context = *VKContext::get();
VKShader *shader = static_cast<VKShader *>(context.shader);
VKCommandBuffer &command_buffer = context.command_buffer_get();
VKPipeline &pipeline = shader->pipeline_get();
VKDescriptorSet &descriptor_set = pipeline.descriptor_set_get();
VKPushConstants &push_constants = pipeline.push_constants_get();
push_constants.update(context);
descriptor_set.update(context.device_get());
command_buffer.bind(
descriptor_set, shader->vk_pipeline_layout_get(), VK_PIPELINE_BIND_POINT_COMPUTE);
command_buffer.dispatch(groups_x_len, groups_y_len, groups_z_len);
}
void VKBackend::compute_dispatch_indirect(StorageBuf * /*indirect_buf*/)
{
}
Context *VKBackend::context_alloc(void *ghost_window, void *ghost_context)
{
return new VKContext(ghost_window, ghost_context);
}
Batch *VKBackend::batch_alloc()
{
return new VKBatch();
}
DrawList *VKBackend::drawlist_alloc(int /*list_length*/)
{
return new VKDrawList();
}
Fence *VKBackend::fence_alloc()
{
return new VKFence();
}
FrameBuffer *VKBackend::framebuffer_alloc(const char *name)
{
return new VKFrameBuffer(name);
}
IndexBuf *VKBackend::indexbuf_alloc()
{
return new VKIndexBuffer();
}
PixelBuffer *VKBackend::pixelbuf_alloc(uint size)
{
return new VKPixelBuffer(size);
}
QueryPool *VKBackend::querypool_alloc()
{
return new VKQueryPool();
}
Shader *VKBackend::shader_alloc(const char *name)
{
return new VKShader(name);
}
Texture *VKBackend::texture_alloc(const char *name)
{
return new VKTexture(name);
}
UniformBuf *VKBackend::uniformbuf_alloc(int size, const char *name)
{
return new VKUniformBuffer(size, name);
}
StorageBuf *VKBackend::storagebuf_alloc(int size, GPUUsageType usage, const char *name)
{
return new VKStorageBuffer(size, usage, name);
}
VertBuf *VKBackend::vertbuf_alloc()
{
return new VKVertexBuffer();
}
void VKBackend::render_begin()
{
}
void VKBackend::render_end()
{
}
void VKBackend::render_step()
{
}
shaderc::Compiler &VKBackend::get_shaderc_compiler()
{
return shaderc_compiler_;
}
void VKBackend::capabilities_init(VKContext & /*context*/)
{
/* Reset all capabilities from previous context. */
GCaps = {};
GCaps.compute_shader_support = true;
GCaps.shader_storage_buffer_objects_support = true;
GCaps.shader_image_load_store_support = true;
}
} // namespace blender::gpu