ImDrawList: Uses IM_COL32_A_MASK macro instead of hardcoded zero alpha testing (#844)

imgui.h

@@ -1040,11 +1040,13 @@ struct ImGuiSizeConstraintCallbackData
 #define IM_COL32_G_SHIFT    8
 #define IM_COL32_B_SHIFT    0
 #define IM_COL32_A_SHIFT    24
+#define IM_COL32_A_MASK     0xFF000000
 #else
 #define IM_COL32_R_SHIFT    0
 #define IM_COL32_G_SHIFT    8
 #define IM_COL32_B_SHIFT    16
 #define IM_COL32_A_SHIFT    24
+#define IM_COL32_A_MASK     0xFF000000
 #endif
 #define IM_COL32(R,G,B,A)    (((ImU32)(A)<<IM_COL32_A_SHIFT) | ((ImU32)(B)<<IM_COL32_B_SHIFT) | ((ImU32)(G)<<IM_COL32_G_SHIFT) | ((ImU32)(R)<<IM_COL32_R_SHIFT))
 #define IM_COL32_WHITE       IM_COL32(255,255,255,255)  // Opaque white

imgui_draw.cpp

@@ -799,7 +799,7 @@ void ImDrawList::PathRect(const ImVec2& a, const ImVec2& b, float rounding, int
 
 void ImDrawList::AddLine(const ImVec2& a, const ImVec2& b, ImU32 col, float thickness)
 {
-    if ((col >> 24) == 0)
+    if ((col & IM_COL32_A_MASK) == 0)
         return;
     PathLineTo(a + ImVec2(0.5f,0.5f));
     PathLineTo(b + ImVec2(0.5f,0.5f));
@@ -809,7 +809,7 @@ void ImDrawList::AddLine(const ImVec2& a, const ImVec2& b, ImU32 col, float thic
 // a: upper-left, b: lower-right. we don't render 1 px sized rectangles properly.
 void ImDrawList::AddRect(const ImVec2& a, const ImVec2& b, ImU32 col, float rounding, int rounding_corners, float thickness)
 {
-    if ((col >> 24) == 0)
+    if ((col & IM_COL32_A_MASK) == 0)
         return;
     PathRect(a + ImVec2(0.5f,0.5f), b - ImVec2(0.5f,0.5f), rounding, rounding_corners);
     PathStroke(col, true, thickness);
@@ -817,7 +817,7 @@ void ImDrawList::AddRect(const ImVec2& a, const ImVec2& b, ImU32 col, float roun
 
 void ImDrawList::AddRectFilled(const ImVec2& a, const ImVec2& b, ImU32 col, float rounding, int rounding_corners)
 {
-    if ((col >> 24) == 0)
+    if ((col & IM_COL32_A_MASK) == 0)
         return;
     if (rounding > 0.0f)
     {
@@ -833,7 +833,7 @@ void ImDrawList::AddRectFilled(const ImVec2& a, const ImVec2& b, ImU32 col, floa
 
 void ImDrawList::AddRectFilledMultiColor(const ImVec2& a, const ImVec2& c, ImU32 col_upr_left, ImU32 col_upr_right, ImU32 col_bot_right, ImU32 col_bot_left)
 {
-    if (((col_upr_left | col_upr_right | col_bot_right | col_bot_left) >> 24) == 0)
+    if (((col_upr_left | col_upr_right | col_bot_right | col_bot_left) & IM_COL32_A_MASK) == 0)
         return;
 
     const ImVec2 uv = GImGui->FontTexUvWhitePixel;
@@ -848,7 +848,7 @@ void ImDrawList::AddRectFilledMultiColor(const ImVec2& a, const ImVec2& c, ImU32
 
 void ImDrawList::AddQuad(const ImVec2& a, const ImVec2& b, const ImVec2& c, const ImVec2& d, ImU32 col, float thickness)
 {
-    if ((col >> 24) == 0)
+    if ((col & IM_COL32_A_MASK) == 0)
         return;
 
     PathLineTo(a);
@@ -860,7 +860,7 @@ void ImDrawList::AddQuad(const ImVec2& a, const ImVec2& b, const ImVec2& c, cons
 
 void ImDrawList::AddQuadFilled(const ImVec2& a, const ImVec2& b, const ImVec2& c, const ImVec2& d, ImU32 col)
 {
-    if ((col >> 24) == 0)
+    if ((col & IM_COL32_A_MASK) == 0)
         return;
 
     PathLineTo(a);
@@ -872,7 +872,7 @@ void ImDrawList::AddQuadFilled(const ImVec2& a, const ImVec2& b, const ImVec2& c
 
 void ImDrawList::AddTriangle(const ImVec2& a, const ImVec2& b, const ImVec2& c, ImU32 col, float thickness)
 {
-    if ((col >> 24) == 0)
+    if ((col & IM_COL32_A_MASK) == 0)
         return;
 
     PathLineTo(a);
@@ -883,7 +883,7 @@ void ImDrawList::AddTriangle(const ImVec2& a, const ImVec2& b, const ImVec2& c,
 
 void ImDrawList::AddTriangleFilled(const ImVec2& a, const ImVec2& b, const ImVec2& c, ImU32 col)
 {
-    if ((col >> 24) == 0)
+    if ((col & IM_COL32_A_MASK) == 0)
         return;
 
     PathLineTo(a);
@@ -894,7 +894,7 @@ void ImDrawList::AddTriangleFilled(const ImVec2& a, const ImVec2& b, const ImVec
 
 void ImDrawList::AddCircle(const ImVec2& centre, float radius, ImU32 col, int num_segments, float thickness)
 {
-    if ((col >> 24) == 0)
+    if ((col & IM_COL32_A_MASK) == 0)
         return;
 
     const float a_max = IM_PI*2.0f * ((float)num_segments - 1.0f) / (float)num_segments;
@@ -904,7 +904,7 @@ void ImDrawList::AddCircle(const ImVec2& centre, float radius, ImU32 col, int nu
 
 void ImDrawList::AddCircleFilled(const ImVec2& centre, float radius, ImU32 col, int num_segments)
 {
-    if ((col >> 24) == 0)
+    if ((col & IM_COL32_A_MASK) == 0)
         return;
 
     const float a_max = IM_PI*2.0f * ((float)num_segments - 1.0f) / (float)num_segments;
@@ -914,7 +914,7 @@ void ImDrawList::AddCircleFilled(const ImVec2& centre, float radius, ImU32 col,
 
 void ImDrawList::AddBezierCurve(const ImVec2& pos0, const ImVec2& cp0, const ImVec2& cp1, const ImVec2& pos1, ImU32 col, float thickness, int num_segments)
 {
-    if ((col >> 24) == 0)
+    if ((col & IM_COL32_A_MASK) == 0)
         return;
 
     PathLineTo(pos0);
@@ -924,7 +924,7 @@ void ImDrawList::AddBezierCurve(const ImVec2& pos0, const ImVec2& cp0, const ImV
 
 void ImDrawList::AddText(const ImFont* font, float font_size, const ImVec2& pos, ImU32 col, const char* text_begin, const char* text_end, float wrap_width, const ImVec4* cpu_fine_clip_rect)
 {
-    if ((col >> 24) == 0)
+    if ((col & IM_COL32_A_MASK) == 0)
         return;
 
     if (text_end == NULL)
@@ -959,7 +959,7 @@ void ImDrawList::AddText(const ImVec2& pos, ImU32 col, const char* text_begin, c
 
 void ImDrawList::AddImage(ImTextureID user_texture_id, const ImVec2& a, const ImVec2& b, const ImVec2& uv0, const ImVec2& uv1, ImU32 col)
 {
-    if ((col >> 24) == 0)
+    if ((col & IM_COL32_A_MASK) == 0)
         return;
 
     // FIXME-OPT: This is wasting draw calls.
@@ -1169,7 +1169,7 @@ static void         Decode85(const unsigned char* src, unsigned char* dst)
     while (*src)
     {
         unsigned int tmp = Decode85Byte(src[0]) + 85*(Decode85Byte(src[1]) + 85*(Decode85Byte(src[2]) + 85*(Decode85Byte(src[3]) + 85*Decode85Byte(src[4]))));
-        dst[0] = ((tmp >> 0) & 0xFF); dst[1] = ((tmp >> 8) & 0xFF); dst[2] = ((tmp >> 16) & 0xFF); dst[3] = ((tmp >> 24) & 0xFF);   // We can't assume little-endianess.
+        dst[0] = ((tmp >> 0) & 0xFF); dst[1] = ((tmp >> 8) & 0xFF); dst[2] = ((tmp >> 16) & 0xFF); dst[3] = ((tmp >> 24) & 0xFF);   // We can't assume little-endianness.
         src += 5;
         dst += 4;
     }