Implement ImGui window for scissor rectangles

This is mainly for debugging, and is only exposed by manually editing the configuration.

Source/Core/VideoCommon/Statistics.cpp

@@ -3,18 +3,26 @@
 
 #include "VideoCommon/Statistics.h"
 
+#include <cstring>
 #include <utility>
 
 #include <imgui.h>
 
+#include "VideoCommon/BPFunctions.h"
 #include "VideoCommon/VideoCommon.h"
 #include "VideoCommon/VideoConfig.h"
 
 Statistics g_stats;
+static bool clear_scissors;
 
 void Statistics::ResetFrame()
 {
   this_frame = {};
+  clear_scissors = true;
+  if (scissors.size() > 1)
+  {
+    scissors.erase(scissors.begin(), scissors.end() - 1);
+  }
 }
 
 void Statistics::SwapDL()
@@ -121,3 +129,355 @@ void Statistics::DisplayProj() const
 
   ImGui::End();
 }
+
+void Statistics::AddScissorRect()
+{
+  if (clear_scissors)
+  {
+    scissors.clear();
+    clear_scissors = false;
+  }
+
+  BPFunctions::ScissorResult scissor = BPFunctions::ComputeScissorRects();
+  bool add;
+  if (scissors.empty())
+  {
+    add = true;
+  }
+  else
+  {
+    if (allow_duplicate_scissors)
+    {
+      // Only check the last entry
+      add = !scissors.back().Matches(scissor, show_scissors, show_viewports);
+    }
+    else
+    {
+      add = std::find_if(scissors.begin(), scissors.end(), [&](auto& s) {
+              return s.Matches(scissor, show_scissors, show_viewports);
+            }) == scissors.end();
+    }
+  }
+  if (add)
+    scissors.push_back(std::move(scissor));
+}
+
+void Statistics::DisplayScissor()
+{
+  // TODO: This is the same position as the regular statistics text
+  const float scale = ImGui::GetIO().DisplayFramebufferScale.x;
+  ImGui::SetNextWindowPos(ImVec2(10.0f * scale, 10.0f * scale), ImGuiCond_FirstUseEver);
+
+  if (!ImGui::Begin("Scissor Rectangles", nullptr, ImGuiWindowFlags_AlwaysAutoResize))
+  {
+    ImGui::End();
+    return;
+  }
+
+  if (ImGui::TreeNode("Options"))
+  {
+    ImGui::Checkbox("Allow Duplicates", &allow_duplicate_scissors);
+    ImGui::Checkbox("Show Scissors", &show_scissors);
+    ImGui::BeginDisabled(!show_scissors);
+    ImGui::Checkbox("Show Raw Values", &show_raw_scissors);
+    ImGui::EndDisabled();
+    ImGui::Checkbox("Show Viewports", &show_viewports);
+    ImGui::Checkbox("Show Text", &show_text);
+    ImGui::DragInt("Scale", &scissor_scale, .2f, 1, 16);
+    ImGui::DragInt("Expected Scissor Count", &scissor_expected_count, .2f, 0, 16);
+    ImGui::TreePop();
+  }
+
+  ImGui::BeginDisabled(current_scissor == 0);
+  if (ImGui::ArrowButton("##left", ImGuiDir_Left))
+  {
+    current_scissor--;
+  }
+  ImGui::EndDisabled();
+  ImGui::SameLine();
+  ImGui::BeginDisabled(current_scissor >= scissors.size());
+  if (ImGui::ArrowButton("##right", ImGuiDir_Right))
+  {
+    current_scissor++;
+    if (current_scissor > scissors.size())
+    {
+      current_scissor = scissors.size();
+    }
+  }
+  ImGui::EndDisabled();
+  ImGui::SameLine();
+  if (current_scissor == 0)
+    ImGui::Text("Displaying all %zu rectangle(s)", scissors.size());
+  else if (current_scissor <= scissors.size())
+    ImGui::Text("Displaying rectangle %zu / %zu", current_scissor, scissors.size());
+  else
+    ImGui::Text("Displaying rectangle %zu / %zu (OoB)", current_scissor, scissors.size());
+
+  ImDrawList* draw_list = ImGui::GetWindowDrawList();
+  ImVec2 p = ImGui::GetCursorScreenPos();
+  ImGui::Dummy(ImVec2(1024 * 3 / scissor_scale, 1024 * 3 / scissor_scale));
+
+  constexpr int DRAW_START = -1024;
+  constexpr int DRAW_END = DRAW_START + 3 * 1024;
+
+  const auto vec = [&](int x, int y, int xoff = 0, int yoff = 0) {
+    return ImVec2(p.x + int(float(x - DRAW_START) / scissor_scale) + xoff,
+                  p.y + int(float(y - DRAW_START) / scissor_scale) + yoff);
+  };
+
+  const auto light_grey = ImGui::GetColorU32(ImVec4(.5f, .5f, .5f, 1.f));
+
+  // Draw gridlines
+  for (int x = DRAW_START; x <= DRAW_END; x += 1024)
+    draw_list->AddLine(vec(x, DRAW_START), vec(x, DRAW_END), light_grey);
+  for (int y = DRAW_START; y <= DRAW_END; y += 1024)
+    draw_list->AddLine(vec(DRAW_START, y), vec(DRAW_END, y), light_grey);
+
+  const auto draw_x = [&](int x, int y, int size, ImU32 col) {
+    // Add an extra offset on the second parameter as otherwise ImGui seems to give results that are
+    // too small on one side
+    draw_list->AddLine(vec(x, y, -size, -size), vec(x, y, +size + 1, +size + 1), col);
+    draw_list->AddLine(vec(x, y, -size, +size), vec(x, y, +size + 1, -size - 1), col);
+  };
+  const auto draw_rect = [&](int x0, int y0, int x1, int y1, ImU32 col, bool show_oob = true) {
+    x0 = std::clamp(x0, DRAW_START, DRAW_END);
+    y0 = std::clamp(y0, DRAW_START, DRAW_END);
+    x1 = std::clamp(x1, DRAW_START, DRAW_END);
+    y1 = std::clamp(y1, DRAW_START, DRAW_END);
+    if (x0 < x1 && y0 < y1)
+    {
+      draw_list->AddRect(vec(x0, y0), vec(x1, y1), col);
+    }
+    else if (show_oob)
+    {
+      // Markers at the two corners, for when they don't form a valid rectangle.
+      draw_list->AddLine(vec(x0, y0), vec(x0, y0, 8, 0), col);
+      draw_list->AddLine(vec(x0, y0), vec(x0, y0, 0, 8), col);
+      draw_list->AddLine(vec(x1, y1), vec(x1, y1, -8, 0), col);
+      draw_list->AddLine(vec(x1, y1), vec(x1, y1, 0, -8), col);
+    }
+  };
+  static std::array<ImVec4, 6> COLORS = {
+      ImVec4(1, 0, 0, 1), ImVec4(1, 1, 0, 1), ImVec4(0, 1, 0, 1),
+      ImVec4(0, 1, 1, 1), ImVec4(0, 0, 1, 1), ImVec4(1, 0, 1, 1),
+  };
+  const auto draw_scissor = [&](size_t index) {
+    const auto& info = scissors[index];
+    const ImU32 col = ImGui::GetColorU32(COLORS[index % COLORS.size()]);
+    int x_off = info.scissor_off.x << 1;
+    int y_off = info.scissor_off.y << 1;
+    // Subtract 2048 instead of 1024, because when x_off is large enough we need to show two
+    // rectangles in the upper sections
+    for (int y = y_off - 2048; y < DRAW_END; y += 1024)
+    {
+      for (int x = x_off - 2048; x < DRAW_END; x += 1024)
+      {
+        draw_rect(x, y, x + EFB_WIDTH, y + EFB_HEIGHT, col, false);
+      }
+    }
+    // Use the full offset here so that ones that have the extra bit set show up distinctly
+    draw_x(info.scissor_off.x_full << 1, info.scissor_off.y_full << 1, 4, col);
+
+    if (show_scissors)
+    {
+      draw_rect(info.scissor_tl.x, info.scissor_tl.y, info.scissor_br.x + 1, info.scissor_br.y + 1,
+                col);
+    }
+    if (show_viewports)
+    {
+      draw_rect(info.viewport_left, info.viewport_top, info.viewport_right, info.viewport_bottom,
+                col);
+    }
+    for (size_t i = 0; i < info.m_result.size(); i++)
+    {
+      // The last entry in the sorted list of results is the one that is used by hardware backends
+      const u8 new_alpha = (i == info.m_result.size() - 1) ? 0x40 : 0x80;
+      const ImU32 new_col = (col & ~IM_COL32_A_MASK) | (new_alpha << IM_COL32_A_SHIFT);
+
+      const auto& r = info.m_result[i];
+      draw_list->AddRectFilled(vec(r.rect.left + r.x_off, r.rect.top + r.y_off),
+                               vec(r.rect.right + r.x_off, r.rect.bottom + r.y_off), new_col);
+    }
+  };
+  constexpr auto NUM_SCISSOR_COLUMNS = 8;
+  const auto draw_scissor_table_header = [&]() {
+    ImGui::TableSetupColumn("#");
+    ImGui::TableSetupColumn("x0");
+    ImGui::TableSetupColumn("y0");
+    ImGui::TableSetupColumn("x1");
+    ImGui::TableSetupColumn("y1");
+    ImGui::TableSetupColumn("xOff");
+    ImGui::TableSetupColumn("yOff");
+    ImGui::TableSetupColumn("Affected");
+    ImGui::TableHeadersRow();
+  };
+  const auto draw_scissor_table_row = [&](size_t index) {
+    const auto& info = scissors[index];
+    int x_off = (info.scissor_off.x << 1) - info.viewport_top;
+    int y_off = (info.scissor_off.y << 1) - info.viewport_left;
+    int x0 = info.scissor_tl.x - info.viewport_top;
+    int x1 = info.scissor_br.x - info.viewport_left;
+    int y0 = info.scissor_tl.y - info.viewport_top;
+    int y1 = info.scissor_br.y - info.viewport_left;
+    ImGui::TableNextColumn();
+    ImGui::TextColored(COLORS[index % COLORS.size()], "%zu", index + 1);
+    ImGui::TableNextColumn();
+    ImGui::Text("%d", x0);
+    ImGui::TableNextColumn();
+    ImGui::Text("%d", y0);
+    ImGui::TableNextColumn();
+    ImGui::Text("%d", x1);
+    ImGui::TableNextColumn();
+    ImGui::Text("%d", y1);
+    ImGui::TableNextColumn();
+    ImGui::Text("%d", x_off);
+    ImGui::TableNextColumn();
+    ImGui::Text("%d", y_off);
+
+    // Visualization of where things are updated on screen with this specific scissor
+    ImGui::TableNextColumn();
+    float scale = ImGui::GetTextLineHeight() / EFB_HEIGHT;
+    if (show_raw_scissors)
+      scale += ImGui::GetTextLineHeightWithSpacing() / EFB_HEIGHT;
+    ImVec2 p2 = ImGui::GetCursorScreenPos();
+    // Use a height of 1 since we want this to span two table rows (if possible)
+    ImGui::Dummy(ImVec2(EFB_WIDTH * scale, 1));
+    for (size_t i = 0; i < info.m_result.size(); i++)
+    {
+      // The last entry in the sorted list of results is the one that is used by hardware backends
+      const u8 new_alpha = (i == info.m_result.size() - 1) ? 0x80 : 0x40;
+      const ImU32 col = ImGui::GetColorU32(COLORS[index % COLORS.size()]);
+      const ImU32 new_col = (col & ~IM_COL32_A_MASK) | (new_alpha << IM_COL32_A_SHIFT);
+
+      const auto& r = info.m_result[i];
+      draw_list->AddRectFilled(ImVec2(p2.x + r.rect.left * scale, p2.y + r.rect.top * scale),
+                               ImVec2(p2.x + r.rect.right * scale, p2.y + r.rect.bottom * scale),
+                               new_col);
+    }
+    draw_list->AddRect(p2, ImVec2(p2.x + EFB_WIDTH * scale, p2.y + EFB_HEIGHT * scale), light_grey);
+    ImGui::SameLine();
+    ImGui::Text("%d", int(info.m_result.size()));
+
+    if (show_raw_scissors)
+    {
+      ImGui::TableNextColumn();
+      ImGui::TextColored(COLORS[index % COLORS.size()], "Raw");
+      ImGui::TableNextColumn();
+      ImGui::Text("%d", info.scissor_tl.x_full.Value());
+      ImGui::TableNextColumn();
+      ImGui::Text("%d", info.scissor_tl.y_full.Value());
+      ImGui::TableNextColumn();
+      ImGui::Text("%d", info.scissor_br.x_full.Value());
+      ImGui::TableNextColumn();
+      ImGui::Text("%d", info.scissor_br.y_full.Value());
+      ImGui::TableNextColumn();
+      ImGui::Text("%d", info.scissor_off.x_full.Value());
+      ImGui::TableNextColumn();
+      ImGui::Text("%d", info.scissor_off.y_full.Value());
+      ImGui::TableNextColumn();
+    }
+  };
+  const auto scissor_table_skip_row = [&](size_t index) {
+    ImGui::TableNextRow();
+    ImGui::TableNextColumn();
+    ImGui::TextColored(COLORS[index % COLORS.size()], "%zu", index + 1);
+    if (show_raw_scissors)
+    {
+      ImGui::TableNextRow();
+      ImGui::TableNextColumn();
+      ImGui::TextColored(COLORS[index % COLORS.size()], "Raw");
+    }
+  };
+  constexpr auto NUM_VIEWPORT_COLUMNS = 5;
+  const auto draw_viewport_table_header = [&]() {
+    ImGui::TableSetupColumn("#");
+    ImGui::TableSetupColumn("vx0");
+    ImGui::TableSetupColumn("vy0");
+    ImGui::TableSetupColumn("vx1");
+    ImGui::TableSetupColumn("vy1");
+    ImGui::TableHeadersRow();
+  };
+  const auto draw_viewport_table_row = [&](size_t index) {
+    const auto& info = scissors[index];
+    ImGui::TableNextColumn();
+    ImGui::TextColored(COLORS[index % COLORS.size()], "%zu", index + 1);
+    ImGui::TableNextColumn();
+    ImGui::Text("%.1f", info.viewport_left);
+    ImGui::TableNextColumn();
+    ImGui::Text("%.1f", info.viewport_top);
+    ImGui::TableNextColumn();
+    ImGui::Text("%.1f", info.viewport_right);
+    ImGui::TableNextColumn();
+    ImGui::Text("%.1f", info.viewport_bottom);
+  };
+  const auto viewport_table_skip_row = [&](size_t index) {
+    ImGui::TableNextRow();
+    ImGui::TableNextColumn();
+    ImGui::TextColored(COLORS[index % COLORS.size()], "%zu", index + 1);
+  };
+  if (current_scissor == 0)
+  {
+    for (size_t i = 0; i < scissors.size(); i++)
+      draw_scissor(i);
+    if (show_text)
+    {
+      if (show_scissors)
+      {
+        if (ImGui::BeginTable("Scissors", NUM_SCISSOR_COLUMNS))
+        {
+          draw_scissor_table_header();
+          for (size_t i = 0; i < scissors.size(); i++)
+            draw_scissor_table_row(i);
+          for (size_t i = scissors.size(); i < scissor_expected_count; i++)
+            scissor_table_skip_row(i);
+          ImGui::EndTable();
+        }
+      }
+      if (show_viewports)
+      {
+        if (ImGui::BeginTable("Viewports", NUM_VIEWPORT_COLUMNS))
+        {
+          draw_viewport_table_header();
+          for (size_t i = 0; i < scissors.size(); i++)
+            draw_viewport_table_row(i);
+          for (size_t i = scissors.size(); i < scissor_expected_count; i++)
+            viewport_table_skip_row(i);
+          ImGui::EndTable();
+        }
+      }
+    }
+  }
+  else if (current_scissor <= scissors.size())
+  {
+    // This bounds check is needed since we only clamp when changing the value; different frames may
+    // have different numbers
+    draw_scissor(current_scissor - 1);
+    if (show_text)
+    {
+      if (show_scissors)
+      {
+        if (ImGui::BeginTable("Scissors", NUM_SCISSOR_COLUMNS))
+        {
+          draw_scissor_table_header();
+          draw_scissor_table_row(current_scissor - 1);
+          ImGui::EndTable();
+        }
+        if (ImGui::BeginTable("Viewports", NUM_VIEWPORT_COLUMNS))
+        {
+          draw_viewport_table_header();
+          draw_viewport_table_row(current_scissor - 1);
+          ImGui::EndTable();
+        }
+      }
+    }
+  }
+  else if (show_text)
+  {
+    if (show_scissors)
+      ImGui::Text("Scissor %zu: Does not exist", current_scissor);
+    if (show_viewports)
+      ImGui::Text("Viewport %zu: Does not exist", current_scissor);
+  }
+
+  ImGui::End();
+}