Method evaluateVar

qrenderdoc/Windows/ShaderViewer.cpp:3447–3697

}

const RDTreeWidgetItem *ShaderViewer::evaluateVar(const RDTreeWidgetItem *item, uint32_t swizzle,
                                                  ShaderVariable *var,
                                                  SourceVariableMapping *mappingPtr)
{
  VariableTag tag = item->tag().value<VariableTag>();

  // if the tag is invalid, it's not a proper match
  if(tag.absoluteRefPath.empty())
    return NULL;

  // if we have a debug var tag then it's easy-mode
  if(tag.debugVarType != DebugVariableType::Undefined)
  {
    // found a match. If we don't want the variable contents, just return true now
    if(!var)
      return item;

    DebugVariableReference debugVar;
    debugVar.type = tag.debugVarType;
    debugVar.name = tag.absoluteRefPath;

    const ShaderVariable *reg = GetDebugVariable(debugVar);

    if(reg)
    {
      *var = *reg;
      var->name = debugVar.name;

      if(swizzle != ~0U)
      {
        // only support swizzles if the debug variable is a plain vector or scalar
        if(!reg->members.empty() || reg->rows > 1)
          return NULL;

        var->value = ShaderValue();

        size_t compSize = VarTypeByteSize(var->type);
        for(uint32_t i = 0; i < 4; i++)
        {
          uint8_t sw = (swizzle >> (i * 8)) & 0xff;

          if(sw == 0xff)
          {
            // swizzle has finished, truncate
            break;
          }
          else if(sw < reg->columns)
          {
            var->columns = i + 1;

            memcpy(var->value.u8v.data() + compSize * i, reg->value.u8v.data() + compSize * sw,
                   compSize);
          }
          else
          {
            // out of bounds swizzle
            return NULL;
          }