RenderPipeline | Physically Based Shading and Deferred Rendering | Game Engine library

I'm trying to render a rectangle using Metal. But the rectangle is skewed as in the screenshot. I would like to understand what's going wrong here.

It seems like vertices of the rectangle aren't loaded correctly using the vertex index. I'm trying to follow the example as in this article - https://coldfunction.com/mgen/p/5a

Below is the code for MetalView and the shader used -

I have been trying to achieve this effect from Tim-C (which all seems to be outdated, even the fixes posted in the comments) with ShaderGraph (Unity 2019.3.0f3), but as far as I know you can't do that within ShaderGraph, so after looking at this page on the ShaderLab documentation I came up with the following shaders that use a shader graph I made.

Using this shader displays the shader graph completely fine:

I'm trying to represent the pipeline system of the Zuul-CI project using Dhall types: a pipeline can use different connections with different trigger events.

I'd like to provide a default pipeline that setups the correct trigger event for each type of connections in such a way that:

In this Swift Metal example I do not understand the concept of extentions and how they are used here. In an effort to understand it can anyone explain to me what is extended in this example?

I did masking like this in opengl as follows

I am trying to implement a metal-backed drawing application where brushstrokes are drawn on an MTKView by stamping a textured square repeatedly along a path. The problem I'm having is that, while each brush stamp properly shows the texture's opacity, overlapping squares do not build value, but rather override each other. In the caption below, each stamp is a textured circle with an alpha component

I have a feeling that because all the stamps are being rendered at once, there is no way for the renderer to "build up" value. However, I'm a little out of my depth with my metal know-how, so I'm hoping someone can point me in the right direction.

Below is further pertinent information:

For a single brush stroke, all geometry is stored in an array vertexArrayBrush3DMesh that contains all the square stamps (each square is made up of 2 triangles). The coordinates for each vertex have a z-value of 0.0 which means they all occupy the same 3d 'plane'. Could this be an issue? (I tested putting randomized z-values, but I saw no visual difference in behavior)

Below is my renderPipeline set up. Note that ".isBlendingEnabled = true" and ".alphaBlendingOperation = .add" are both commented out, as they had no effect in solving my problem

First of all, I'm a total newbie with Vulkan (I'm using the binding provided by LWJGL). I know I should copy/paste more code, but I don't even know what would be relevant for now (so don't hesitate to ask me some specific piece of code).

I try to make something like that :

• Use a ComputeShader to compute a buffer of pixel.
• Use vkCmdCopyBufferToImage to directly copy this array into a framebuffer image.

So, no vertex/fragment shaders for now.

I allocated a Compute Pipeline, and a FrameBuffer. I have one {Queue/CommandPool/CommandBuffer} for Computation, and one other for Rendering.

When I try to submit the graphic queue with:

I am very new to metal so bear with me as I am transitioning from the ugly state machine calls of OpenGL to modern graphics frameworks. I really want to make sure I understand how everything works and works together.

I have read most of Apples documentation but it does a better job describing the function of individual components than how they come together.

I am trying to understand essentially whether I should have multiple renderPipelines and renderEncoders are needed in my situation.

To describe my pipeline at a high level here is what goes on:

1. Retrieve the previous frame's contents from an offscreen texture that was rendered to and draw some new contents onto it.
2. Swith to rendering on the screen. Draw the texture from step 1 to the screen.
3. Do some post processing (in native resolution).
4. Draw the UI ontop as quads. (essentailly a repeat of 2)

So in essence there will be the following vertex/fragment shader pairs

• Draw the entities (step 1)
• Draw quads on a specefied area (step 2 and 4)
• Post processing shader 1 (step 3) uses different inputs than D and cant be done in the same shader
• Post processing shader 2 (step 3) uses different inputs than C and can't be done in the same shader

There will be the following texture groups

• Texture for each UI element
• Texture for the offscreen drawing done in step 1
• Potentially more offscreen textures will be used in post processing depening on metals preformance

Ultimately my confusions are this:

• Q1. Render Pipelines take only one vertex and one fragment function so does this mean I need have 4 render pipelines even though I only have 3 unique steps to my drawing procedure?
• Q2. How am I supposed to use multiple pipelines in one encoder? Wouldn't each sucessive call on .setRenderPipelineState override the previous one?
• Q3. Would you recommend keeping all of my .setFragmentTexture calls right after creating my encoder or do I need to set those only right before they are needed.
• Q4. Is it valid to keep my depthState constant even as I switch between pipelineStates? How do I ensure that my entities on step 1 are rendered with depth but make sure depth information is lost between frames so entities are all on top of the previous contents?
• Q5. What do I do with render step 3 where I have two post processing steps? Do those have to be seperate pipelines?
• Q6. How can I efficiently build my pipeline knowing that steps 2 and 4 are essentially the same just with different inputs?

I guess it would help me if someone would walk me through what renderPipelineObjects I will need and for what. It would also be useful to understand what some of the renderCommandEncoder commands might look like at a psuedocode level.

Working on fixing performance issue in a Java play with akka framework application. Basically consumes and processes messages from a queue. And uses external service APIs heavily while processing each message. I get in to CPU load issue at certain condition, trying to find a root cause. Here is the thread dump of one of host when CPU ~100%.

I see lot of blocked threads with sun.misc.Unsafe.park and do not see any info of application code. Are these blocked ones waiting for IO? Can you give some hints? Thanks