Method PickPixel

renderdoc/driver/gl/gl_debug.cpp:1825–1925

}

void GLReplay::PickPixel(ResourceId texture, uint32_t x, uint32_t y, const Subresource &sub,
                         CompType typeCast, float pixel[4])
{
  WrappedOpenGL &drv = *m_pDriver;

  MakeCurrentReplayContext(m_DebugCtx);

  drv.glBindFramebuffer(eGL_FRAMEBUFFER, DebugData.pickPixelFBO);
  drv.glBindFramebuffer(eGL_READ_FRAMEBUFFER, DebugData.pickPixelFBO);

  pixel[0] = pixel[1] = pixel[2] = pixel[3] = 0.0f;
  drv.glClearBufferfv(eGL_COLOR, 0, pixel);

  DebugData.outWidth = DebugData.outHeight = 1.0f;
  drv.glViewport(0, 0, 1, 1);

  TextureDisplay texDisplay;

  texDisplay.red = texDisplay.green = texDisplay.blue = texDisplay.alpha = true;
  texDisplay.flipY = false;
  texDisplay.hdrMultiplier = -1.0f;
  texDisplay.linearDisplayAsGamma = true;
  texDisplay.subresource = sub;
  texDisplay.customShaderId = ResourceId();
  texDisplay.rangeMin = 0.0f;
  texDisplay.rangeMax = 1.0f;
  texDisplay.scale = 1.0f;
  texDisplay.resourceId = texture;
  texDisplay.typeCast = typeCast;
  texDisplay.rawOutput = true;
  texDisplay.xOffset = -float(x << sub.mip);
  texDisplay.yOffset = -float(y << sub.mip);

  WrappedOpenGL::TextureData &texDetails = m_pDriver->m_Textures[texDisplay.resourceId];

  uint32_t mipWidth = RDCMAX(1U, (uint32_t)texDetails.width >> sub.mip);
  uint32_t mipHeight = RDCMAX(1U, (uint32_t)texDetails.height >> sub.mip);

  texDisplay.xOffset = -(float(x) / float(mipWidth)) * texDetails.width;
  texDisplay.yOffset = -(float(y) / float(mipHeight)) * texDetails.height;

  RenderTextureInternal(texDisplay, eTexDisplay_MipShift);

  drv.glReadPixels(0, 0, 1, 1, eGL_RGBA, eGL_FLOAT, (void *)pixel);

  if(!HasExt[ARB_gpu_shader5])
  {
    if(IsSIntFormat(texDetails.internalFormat))
    {
      int32_t casted[4] = {
          (int32_t)pixel[0],
          (int32_t)pixel[1],
          (int32_t)pixel[2],
          (int32_t)pixel[3],
      };

      memcpy(pixel, casted, sizeof(casted));
    }