Missing fragment rasterization in certain case

llyzs commented 3 years ago

An example to reproduce the issue:

Creates a 64x320 image with format B8G8R8A8_UNORM as framebuffer and clear it with green {0.0, 1.0, 0.0, 0.0}
Creates another B8G8R8A8_UNORM image of any size as texture and clear it with black {0.0, 0.0, 0.0, 0.0}

Creates the following vertex buffer of total 24 vertices (8 triangles), each is of format R32G32B32A32_SFLOAT (x, y, texcoord_x, texcoord_y). Those triangles were designed to draw on the framebuffer from top to bottom:

{0,        0,  0.0075,   0},
{0,  0.00625,   0.005,   0},
{2, 0.003125, 0.00625, 0.2},
{0,  0.00625,  0.0075, 0.2},
{0,   0.0125,   0.005, 0.2},
{2, 0.009375, 0.00625, 0.4},
{0,   0.0125,  0.0075, 0.4},
{0,  0.01875,   0.005, 0.4},
{2, 0.015625, 0.00625, 0.6},
{0,  0.01875,  0.0075, 0.6},
{0,    0.025,   0.005, 0.6},
{2, 0.021875, 0.00625, 0.8},
{0,    0.025,  0.0075, 0.8},
{0,  0.03125,   0.005, 0.8},
{2, 0.028125, 0.00625,   1},
{0,  0.03125,  0.0075,   1},
{0,   0.0375,   0.005,   1},
{2, 0.034375, 0.00625, 1.2},
{0,   0.0375,  0.0075, 1.2},
{0,  0.04375,   0.005, 1.2},
{2, 0.040625, 0.00625, 1.4},
{0,  0.04375,  0.0075, 1.4},
{0,     0.05,   0.005, 1.4},
{2, 0.046875, 0.00625, 1.6}

Vertex shader: Outputs position (x - 1, 1 - y, 0, 1) and texcoord (texcoord_x / 2, texcoord_y / 2)

; SPIR-V
; Version: 1.3
; Generator: Khronos; 0
; Bound: 50
; Schema: 0
           OpCapability Shader
      %1 = OpExtInstImport "GLSL.std.450"
           OpMemoryModel Logical GLSL450
           OpEntryPoint Vertex %2 "main" %10 %12 %23
           OpDecorate %10 Location 0
           OpDecorate %12 Location 1
           OpMemberDecorate %21 0 BuiltIn Position
           OpDecorate %21 Block
      %3 = OpTypeVoid
      %4 = OpTypeFunction %3
      %7 = OpTypeFloat 32
      %8 = OpTypeVector %7 4
      %9 = OpTypePointer Input %8
     %10 = OpVariable %9 Input
     %11 = OpTypePointer Output %8
     %12 = OpVariable %11 Output
     %15 = OpConstant %7 1
     %16 = OpConstant %7 -1
     %17 = OpConstant %7 0
     %18 = OpConstantComposite %8 %15 %16 %17 %17
     %19 = OpConstantComposite %8 %16 %15 %17 %17
     %21 = OpTypeStruct %8
     %22 = OpTypePointer Output %21
     %23 = OpVariable %22 Output
     %24 = OpTypeInt 32 0
     %25 = OpConstant %24 0
     %30 = OpTypePointer Output %7
     %32 = OpConstant %24 1
     %34 = OpConstantComposite %8 %17 %17 %17 %15
     %38 = OpConstant %24 2
     %40 = OpConstant %24 3
     %43 = OpConstant %7 0.5
     %44 = OpConstantComposite %8 %43 %43 %17 %17
      %2 = OpFunction %3 None %4
      %5 = OpLabel
     %13 = OpLoad %8 %10
     %14 = OpVectorShuffle %8 %13 %13 0 1 0 0
     %20 = OpExtInst %8 %1 Fma %14 %18 %19
     %26 = OpAccessChain %11 %23 %25
     %27 = OpCompositeExtract %7 %20 0
     %28 = OpCompositeExtract %7 %20 1
     %29 = OpAccessChain %30 %26 %25
           OpStore %29 %27
     %31 = OpAccessChain %30 %26 %32
           OpStore %31 %28
     %33 = OpAccessChain %11 %23 %25
     %35 = OpCompositeExtract %7 %34 2
     %36 = OpCompositeExtract %7 %34 3
     %37 = OpAccessChain %30 %33 %38
           OpStore %37 %35
     %39 = OpAccessChain %30 %33 %40
           OpStore %39 %36
     %41 = OpLoad %8 %10
     %42 = OpVectorShuffle %8 %41 %41 2 3 2 2
     %45 = OpFMul %8 %42 %44
     %46 = OpCompositeExtract %7 %45 0
     %47 = OpCompositeExtract %7 %45 1
     %48 = OpAccessChain %30 %12 %25
           OpStore %48 %46
     %49 = OpAccessChain %30 %12 %32
           OpStore %49 %47
           OpReturn
           OpFunctionEnd

Fragment shader: Just samples using texcoord.

; SPIR-V
; Version: 1.3
; Generator: Khronos; 0
; Bound: 27
; Schema: 0
           OpCapability Shader
      %1 = OpExtInstImport "GLSL.std.450"
           OpMemoryModel Logical GLSL450
           OpEntryPoint Fragment %2 "main" %13 %15
           OpExecutionMode %2 OriginUpperLeft
           OpDecorate %9 DescriptorSet 0
           OpDecorate %9 Binding 0
           OpDecorate %13 Location 1
           OpDecorate %15 Location 0
           OpDecorate %18 DescriptorSet 0
           OpDecorate %18 Binding 1
      %3 = OpTypeVoid
      %4 = OpTypeFunction %3
      %7 = OpTypeSampler
      %8 = OpTypePointer UniformConstant %7
      %9 = OpVariable %8 UniformConstant
     %10 = OpTypeFloat 32
     %11 = OpTypeVector %10 4
     %12 = OpTypePointer Input %11
     %13 = OpVariable %12 Input
     %14 = OpTypePointer Output %11
     %15 = OpVariable %14 Output
     %16 = OpTypeImage %10 2D 0 0 0 1 Unknown
     %17 = OpTypePointer UniformConstant %16
     %18 = OpVariable %17 UniformConstant
     %23 = OpTypeVector %10 2
     %24 = OpTypeSampledImage %16
      %2 = OpFunction %3 None %4
      %5 = OpLabel
     %19 = OpLoad %16 %18
     %20 = OpLoad %7 %9
     %21 = OpLoad %11 %13
     %22 = OpVectorShuffle %23 %21 %21 0 1
     %25 = OpSampledImage %24 %19 %20
     %26 = OpImageSampleImplicitLod %11 %25 %22
           OpStore %15 %26
           OpReturn
           OpFunctionEnd

If call vkCmdDraw(15) to draw 5 triangles (or fewer), it renders correctly, a few lines from top are drawn black.
If call vkCmdDraw(18/21/24) to draw 6/7/8 triangles, the top line of pixels is mysteriously not rendered and left green:

Tested with RX6700XT driver 2021.Q3.2.

WenqingLiAMD commented 2 months ago

@llyzs can you test it with latest driver 2024.Q2.2? If the issue persists, can you share the complete source code? Currently I failed to reproduce basing on your description.

WenqingLiAMD commented 2 months ago

Please feel free to reopen if the issue can be reproduced, many thanks!

GPUOpen-Drivers / AMDVLK

Missing fragment rasterization in certain case #246