Demo: Tweaked custom rendering custom, added a Thickness drag. Clarified use of vertical/horizontal line. Add a single pixel demo (wowow)

imgui_demo.cpp

@@ -2628,8 +2628,10 @@ static void ShowExampleAppCustomRendering(bool* p_open)
     // Primitives
     ImGui::Text("Primitives");
     static float sz = 36.0f;
+    static float thickness = 4.0f;
     static ImVec4 col = ImVec4(1.0f,1.0f,0.4f,1.0f);
     ImGui::DragFloat("Size", &sz, 0.2f, 2.0f, 72.0f, "%.0f");
+    ImGui::DragFloat("Thickness", &thickness, 0.05f, 1.0f, 8.0f, "%.02f");
     ImGui::ColorEdit3("Color", &col.x);
     {
         const ImVec2 p = ImGui::GetCursorScreenPos();
@@ -2637,16 +2639,16 @@ static void ShowExampleAppCustomRendering(bool* p_open)
         float x = p.x + 4.0f, y = p.y + 4.0f, spacing = 8.0f;
         for (int n = 0; n < 2; n++)
         {
-            float thickness = (n == 0) ? 1.0f : 4.0f;
-            draw_list->AddCircle(ImVec2(x+sz*0.5f, y+sz*0.5f), sz*0.5f, col32, 20, thickness); x += sz+spacing;
-            draw_list->AddRect(ImVec2(x, y), ImVec2(x+sz, y+sz), col32, 0.0f, ImDrawCornerFlags_All, thickness); x += sz+spacing;
-            draw_list->AddRect(ImVec2(x, y), ImVec2(x+sz, y+sz), col32, 10.0f, ImDrawCornerFlags_All, thickness); x += sz+spacing;
-            draw_list->AddRect(ImVec2(x, y), ImVec2(x+sz, y+sz), col32, 10.0f, ImDrawCornerFlags_TopLeft|ImDrawCornerFlags_BotRight, thickness); x += sz+spacing;
-            draw_list->AddTriangle(ImVec2(x+sz*0.5f, y), ImVec2(x+sz,y+sz-0.5f), ImVec2(x,y+sz-0.5f), col32, thickness); x += sz+spacing;
-            draw_list->AddLine(ImVec2(x, y), ImVec2(x+sz, y   ), col32, thickness); x += sz+spacing;
-            draw_list->AddLine(ImVec2(x, y), ImVec2(x+sz, y+sz), col32, thickness); x += sz+spacing;
-            draw_list->AddLine(ImVec2(x, y), ImVec2(x,    y+sz), col32, thickness); x += spacing;
-            draw_list->AddBezierCurve(ImVec2(x, y), ImVec2(x+sz*1.3f,y+sz*0.3f), ImVec2(x+sz-sz*1.3f,y+sz-sz*0.3f), ImVec2(x+sz, y+sz), col32, thickness);
+            float curr_thickness = (n == 0) ? 1.0f : thickness;
+            draw_list->AddCircle(ImVec2(x+sz*0.5f, y+sz*0.5f), sz*0.5f, col32, 20, curr_thickness); x += sz+spacing;
+            draw_list->AddRect(ImVec2(x, y), ImVec2(x+sz, y+sz), col32, 0.0f, ImDrawCornerFlags_All, curr_thickness); x += sz+spacing;
+            draw_list->AddRect(ImVec2(x, y), ImVec2(x+sz, y+sz), col32, 10.0f, ImDrawCornerFlags_All, curr_thickness); x += sz+spacing;
+            draw_list->AddRect(ImVec2(x, y), ImVec2(x+sz, y+sz), col32, 10.0f, ImDrawCornerFlags_TopLeft|ImDrawCornerFlags_BotRight, curr_thickness); x += sz+spacing;
+            draw_list->AddTriangle(ImVec2(x+sz*0.5f, y), ImVec2(x+sz,y+sz-0.5f), ImVec2(x,y+sz-0.5f), col32, curr_thickness); x += sz+spacing;
+            draw_list->AddLine(ImVec2(x, y), ImVec2(x+sz, y   ), col32, curr_thickness); x += sz+spacing; // Horizontal line (note: drawing a filled rectangle will be faster!)
+            draw_list->AddLine(ImVec2(x, y), ImVec2(x,    y+sz), col32, curr_thickness); x += spacing;    // Vertical line (note: drawing a filled rectangle will be faster!)
+            draw_list->AddLine(ImVec2(x, y), ImVec2(x+sz, y+sz), col32, curr_thickness); x += sz+spacing; // Diagonal line
+            draw_list->AddBezierCurve(ImVec2(x, y), ImVec2(x+sz*1.3f,y+sz*0.3f), ImVec2(x+sz-sz*1.3f,y+sz-sz*0.3f), ImVec2(x+sz, y+sz), col32, curr_thickness);
             x = p.x + 4;
             y += sz+spacing;
         }
@@ -2655,6 +2657,9 @@ static void ShowExampleAppCustomRendering(bool* p_open)
         draw_list->AddRectFilled(ImVec2(x, y), ImVec2(x+sz, y+sz), col32, 10.0f); x += sz+spacing;
         draw_list->AddRectFilled(ImVec2(x, y), ImVec2(x+sz, y+sz), col32, 10.0f, ImDrawCornerFlags_TopLeft|ImDrawCornerFlags_BotRight); x += sz+spacing;
         draw_list->AddTriangleFilled(ImVec2(x+sz*0.5f, y), ImVec2(x+sz,y+sz-0.5f), ImVec2(x,y+sz-0.5f), col32); x += sz+spacing;
+        draw_list->AddRectFilled(ImVec2(x, y), ImVec2(x+sz, y+thickness), col32); x += sz+spacing;          // Horizontal line (faster than AddLine, but only handle integer thickness)
+        draw_list->AddRectFilled(ImVec2(x, y), ImVec2(x+thickness, y+sz), col32); x += spacing+spacing;     // Vertical line (faster than AddLine, but only handle integer thickness)
+        draw_list->AddRectFilled(ImVec2(x, y), ImVec2(x+1, y+1), col32);          x += sz;                  // Pixel (faster than AddLine)
         draw_list->AddRectFilledMultiColor(ImVec2(x, y), ImVec2(x+sz, y+sz), IM_COL32(0,0,0,255), IM_COL32(255,0,0,255), IM_COL32(255,255,0,255), IM_COL32(0,255,0,255));
         ImGui::Dummy(ImVec2((sz+spacing)*8, (sz+spacing)*3));
     }