How To: Set Breakpoints in a Shader

To set a breakpoint in a shader:

1. Access the Shader Debugger.
2. To see the source code of a specific shader, double-click on a row in the Shaders window. The document window opens, showing the corresponding source code.
3. In the Text Editor window, move the insertion point to the line where you want the application to break.
   To set a breakpoint in a statement that spans two or more lines, move the insertion point to the last line of the statement.
4. From the Debug menu, choose Toggle Breakpoint.
   Optionally, press the F9 key, or left-click in the left margin of the source code document.
   
   
   
5. If you wish, you can also set the breakpoint as a conditional breakpoint.  
   1. Right-click on the breakpoint icon in the left margin of the source code document, or on the entry in the "Breakpoints" window, to open the Breakpoint Options dialog box.
   2. Select Conditional.
      The Conditional Breakpoint dialog box opens.
   3. Type the expression to evaluate.
   4. Click OK.
      See below for more information on setting breakpoints in shaders.

Conditional Breakpoints in Shaders

A conditional breakpoint expression can be any HLSL expression that evaluates to a Boolean result. All (scalar) operations (+, -, *, <, >, <=, ==,  ., [], type casts, swizzles … ) on local variables, global variables, and pseudo-variables (intrinsic variables) are allowed.

Limitations

Be aware of the following limitations in expressions for conditional breakpoints:

Additional Intrinsic Variables

There are additional intrinsic variables that you can use, depending on the kind of shader you are debugging:

Shader	can use the following variables in expressions...
Vertex Shader	uint @vertexId uint @instanceId uint @drawCallId
Geometry Shader	uint @primitiveId uint @drawCallId
Pixel Shader	float3 @pixel uint @sampleId uint @drawCallId
Compute Shader	uint3 @groupThreadId uint3 @groupId  uint @dispatchId
Hull Shader	uint @controlPointId uint @drawCallId
Domain Shader	uint @domainPointId uint @drawCallId

The following macros are also supported in Compute Shaders:

#define @GroupIdx(X, Y, Z) (@groupId.x == X && @groupId.y == Y && @groupId.z == Z)

#define @ThreadIdx(X, Y, Z) (@groupThreadId.x == X && @groupThreadId.y == Y && @groupThreadId.z == Z)