Do I need to set viewport and scissor for every framebuffer?

[ggasimzada]

I have set up viewport and scissor as dynamic states for my pipelines and I am updating them if the window is resized (or first draw call):

void VulkanRenderer::setViewportAndScissor(VkCommandBuffer commandBuffer) {
  if (!sizeChanged)
    return;

  VkViewport viewport{};
  viewport.x = 0.0f;
  viewport.y = 0.0f;
  viewport.width = (float)swapchain.getExtent().width;
  viewport.height = (float)swapchain.getExtent().height;
  viewport.minDepth = 0.0f;
  viewport.maxDepth = 1.0f;

  VkRect2D scissor{};
  scissor.offset = {0, 0};
  scissor.extent = swapchain.getExtent();

  vkCmdSetViewport(commandBuffer, 0, 1, &viewport);
  vkCmdSetScissor(commandBuffer, 0, 1, &scissor);
  sizeChanged = true;
}

My renderer creates one command buffer per swapchain and when I acquire a swapchain image, I use the respective command buffer for all the draw related commands:

void VulkanRenderer::draw(Scene *scene) {
  uint32_t imageIdx = swapchain.acquireNextImage(imageAvailableSemaphore);

  vkWaitForFences(context.getDevice(), 1, &renderFence, true,
                  std::numeric_limits<uint32_t>::max());
  vkResetFences(context.getDevice(), 1, &renderFence);

  vkResetCommandBuffer(commandBuffers[imageIdx], 0);

  VkCommandBufferBeginInfo beginInfo{};
  beginInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
  beginInfo.flags = 0;
  beginInfo.pInheritanceInfo = nullptr;

  if (vkBeginCommandBuffer(commandBuffers[imageIdx], &beginInfo) !=
      VK_SUCCESS) {
    throw VulkanError("Failed to begin recording command buffer for frame");
  }

  setViewportAndScissor(commandBuffers[imageIdx]);

  VkClearValue clearValue;
  clearValue.color = {{0.0f, 0.0f, 0.0f, 1.0f}};
  VkClearValue depthClear;
  depthClear.depthStencil.depth = 1.0f;

  VkClearValue clearValues[] = {clearValue, depthClear};

  VkRenderPassBeginInfo renderPassInfo{};
  renderPassInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
  renderPassInfo.renderPass = renderPass;
  renderPassInfo.framebuffer = framebuffers[imageIdx];
  renderPassInfo.renderArea.offset = {0, 0};
  renderPassInfo.renderArea.extent = swapchain.getExtent();
  renderPassInfo.clearValueCount = 2;
  renderPassInfo.pClearValues = clearValues;

  // rest of the call
}

Do I need to write the viewport and scissor for every outputted framebuffer?

[Alfonse_Reinheart]

Most state is not preserved across command buffers. So if you are relying on some state in a CB, then that state needs to be set by that CB.

[krOoze]

You need to set it in each separate command buffer. And you need to set it after each new bound pipeline except when the previous one also had a dynamic viewport.

Anything else does not disturb the viewport dynamic state (e.g. vkCmdBeginRenderPass does not matter).