Added IsMouseReleased() helper (#248)

imgui.cpp

@@ -2089,8 +2089,10 @@ void ImGui::NewFrame()
     g.IO.MousePosPrev = g.IO.MousePos;
     for (size_t i = 0; i < IM_ARRAYSIZE(g.IO.MouseDown); i++)
     {
-        g.IO.MouseDownTime[i] = g.IO.MouseDown[i] ? (g.IO.MouseDownTime[i] < 0.0f ? 0.0f : g.IO.MouseDownTime[i] + g.IO.DeltaTime) : -1.0f;
-        g.IO.MouseClicked[i] = (g.IO.MouseDownTime[i] == 0.0f);
+        g.IO.MouseDownDurationPrev[i] = g.IO.MouseDownDuration[i];
+        g.IO.MouseDownDuration[i] = g.IO.MouseDown[i] ? (g.IO.MouseDownDuration[i] < 0.0f ? 0.0f : g.IO.MouseDownDuration[i] + g.IO.DeltaTime) : -1.0f;
+        g.IO.MouseClicked[i] = g.IO.MouseDownDuration[i] == 0.0f;
+        g.IO.MouseReleased[i] = g.IO.MouseDownDurationPrev[i] >= 0.0f && !g.IO.MouseDown[i];
         g.IO.MouseDoubleClicked[i] = false;
         if (g.IO.MouseClicked[i])
         {
@@ -2894,7 +2896,7 @@ bool ImGui::IsMouseClicked(int button, bool repeat)
 {
     ImGuiState& g = *GImGui;
     IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
-    const float t = g.IO.MouseDownTime[button];
+    const float t = g.IO.MouseDownDuration[button];
     if (t == 0.0f)
         return true;
 
@@ -2908,6 +2910,13 @@ bool ImGui::IsMouseClicked(int button, bool repeat)
     return false;
 }
 
+bool ImGui::IsMouseReleased(int button)
+{
+    ImGuiState& g = *GImGui;
+    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
+    return g.IO.MouseReleased[button];
+}
+
 bool ImGui::IsMouseDoubleClicked(int button)
 {
     ImGuiState& g = *GImGui;
@@ -10561,6 +10570,7 @@ void ImGui::ShowTestWindow(bool* opened)
 
     ImGui::Text("ImGui says hello.");
     //ImGui::Text("MousePos (%g, %g)", ImGui::GetIO().MousePos.x, ImGui::GetIO().MousePos.y);
+    //ImGui::Text("MouseClicked (%d, %d) MouseReleased (%d, %d)", ImGui::GetIO().MouseClicked[0], ImGui::GetIO().MouseClicked[1], ImGui::GetIO().MouseReleased[0], ImGui::GetIO().MouseReleased[1]);
     //ImGui::Text("MouseWheel %d", ImGui::GetIO().MouseWheel);
     //ImGui::Text("KeyMods %s%s%s", ImGui::GetIO().KeyCtrl ? "CTRL" : "", ImGui::GetIO().KeyShift ? "SHIFT" : "", ImGui::GetIO().KeyAlt? "ALT" : "");
     //ImGui::Text("WantCaptureMouse: %d", ImGui::GetIO().WantCaptureMouse);

imgui.h

@@ -356,6 +356,7 @@ namespace ImGui
     IMGUI_API bool          IsMouseDown(int button);
     IMGUI_API bool          IsMouseClicked(int button, bool repeat = false);
     IMGUI_API bool          IsMouseDoubleClicked(int button);
+    IMGUI_API bool          IsMouseReleased(int button);
     IMGUI_API bool          IsMouseHoveringWindow();                                            // is mouse hovering current window ("window" in API names always refer to current window)
     IMGUI_API bool          IsMouseHoveringAnyWindow();                                         // is mouse hovering any active imgui window
     IMGUI_API bool          IsMouseHoveringRect(const ImVec2& rect_min, const ImVec2& rect_max);// is mouse hovering given bounding rect
@@ -701,8 +702,10 @@ struct ImGuiIO
     ImVec2      MouseClickedPos[5];         // Position at time of clicking
     float       MouseClickedTime[5];        // Time of last click (used to figure out double-click)
     bool        MouseDoubleClicked[5];      // Has mouse button been double-clicked?
+    bool        MouseReleased[5];           // Mouse button went from !Down to Down
     bool        MouseDownOwned[5];          // Track if button was clicked inside a window. We don't request mouse capture from the application if click started outside ImGui bounds.
-    float       MouseDownTime[5];           // Time the mouse button has been down
+    float       MouseDownDuration[5];       // Time the mouse button has been down
+    float       MouseDownDurationPrev[5];   // Previous time the mouse button has been down
     float       MouseDragMaxDistanceSqr[5]; // Squared maximum distance of how much mouse has traveled from the click point
     float       KeysDownTime[512];          // Time the keyboard key has been down