Refactor CalcWordWrapPositionA() to take on the responsability of minimum character display. Add CalcWordWrapNextLineStartA(), simplify caller code.

Should be no-op but incrementing IMGUI_VERSION_NUM just in case.
Preparing for #5720

imgui.h

@@ -23,7 +23,7 @@
 // Library Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals, e.g. '#if IMGUI_VERSION_NUM > 12345')
 #define IMGUI_VERSION               "1.89 WIP"
-#define IMGUI_VERSION_NUM           18823
+#define IMGUI_VERSION_NUM           18824
 #define IMGUI_HAS_TABLE
 
 /*

imgui_draw.cpp

@@ -3333,11 +3333,21 @@ const ImFontGlyph* ImFont::FindGlyphNoFallback(ImWchar c) const
     return &Glyphs.Data[i];
 }
 
-const char* ImFont::CalcWordWrapPositionA(float scale, const char* text, const char* text_end, float wrap_width) const
+// Wrapping skips upcoming blanks
+static inline const char* CalcWordWrapNextLineStartA(const char* text, const char* text_end)
 {
-    // Simple word-wrapping for English, not full-featured. Please submit failing cases!
-    // FIXME: Much possible improvements (don't cut things like "word !", "word!!!" but cut within "word,,,,", more sensible support for punctuations, support for Unicode punctuations, etc.)
+    while (text < text_end && ImCharIsBlankA(*text))
+        text++;
+    if (*text == '\n')
+        text++;
+    return text;
+}
 
+// Simple word-wrapping for English, not full-featured. Please submit failing cases!
+// This will return the next location to wrap from. If no wrapping if necessary, this will fast-forward to e.g. text_end.
+// FIXME: Much possible improvements (don't cut things like "word !", "word!!!" but cut within "word,,,,", more sensible support for punctuations, support for Unicode punctuations, etc.)
+const char* ImFont::CalcWordWrapPositionA(float scale, const char* text, const char* text_end, float wrap_width) const
+{
     // For references, possible wrap point marked with ^
     //  "aaa bbb, ccc,ddd. eee   fff. ggg!"
     //      ^    ^    ^   ^   ^__    ^    ^
@@ -3349,7 +3359,6 @@ const char* ImFont::CalcWordWrapPositionA(float scale, const char* text, const c
 
     // Cut words that cannot possibly fit within one line.
     // e.g.: "The tropical fish" with ~5 characters worth of width --> "The tr" "opical" "fish"
-
     float line_width = 0.0f;
     float word_width = 0.0f;
     float blank_width = 0.0f;
@@ -3429,6 +3438,10 @@ const char* ImFont::CalcWordWrapPositionA(float scale, const char* text, const c
         s = next_s;
     }
 
+    // Wrap_width is too small to fit anything. Force displaying 1 character to minimize the height discontinuity.
+    // +1 may not be a character start point in UTF-8 but it's ok because caller loops use (text >= word_wrap_eol).
+    if (s == text && text < text_end)
+        return s + 1;
     return s;
 }
 
@@ -3453,11 +3466,7 @@ ImVec2 ImFont::CalcTextSizeA(float size, float max_width, float wrap_width, cons
         {
             // Calculate how far we can render. Requires two passes on the string data but keeps the code simple and not intrusive for what's essentially an uncommon feature.
             if (!word_wrap_eol)
-            {
                 word_wrap_eol = CalcWordWrapPositionA(scale, s, text_end, wrap_width - line_width);
-                if (word_wrap_eol == s) // Wrap_width is too small to fit anything. Force displaying 1 character to minimize the height discontinuity.
-                    word_wrap_eol++;    // +1 may not be a character start point in UTF-8 but it's ok because we use s >= word_wrap_eol below
-            }
 
             if (s >= word_wrap_eol)
             {
@@ -3466,13 +3475,7 @@ ImVec2 ImFont::CalcTextSizeA(float size, float max_width, float wrap_width, cons
                 text_size.y += line_height;
                 line_width = 0.0f;
                 word_wrap_eol = NULL;
-
-                // Wrapping skips upcoming blanks
-                while (s < text_end)
-                {
-                    const char c = *s;
-                    if (ImCharIsBlankA(c)) { s++; } else if (c == '\n') { s++; break; } else { break; }
-                }
+                s = CalcWordWrapNextLineStartA(s, text_end); // Wrapping skips upcoming blanks
                 continue;
             }
         }
@@ -3557,7 +3560,6 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, const ImVec2& pos, Im
     const float scale = size / FontSize;
     const float line_height = FontSize * scale;
     const bool word_wrap_enabled = (wrap_width > 0.0f);
-    const char* word_wrap_eol = NULL;
 
     // Fast-forward to first visible line
     const char* s = text_begin;
@@ -3597,6 +3599,7 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, const ImVec2& pos, Im
     unsigned int vtx_current_idx = draw_list->_VtxCurrentIdx;
 
     const ImU32 col_untinted = col | ~IM_COL32_A_MASK;
+    const char* word_wrap_eol = NULL;
 
     while (s < text_end)
     {
@@ -3604,24 +3607,14 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, const ImVec2& pos, Im
         {
             // Calculate how far we can render. Requires two passes on the string data but keeps the code simple and not intrusive for what's essentially an uncommon feature.
             if (!word_wrap_eol)
-            {
                 word_wrap_eol = CalcWordWrapPositionA(scale, s, text_end, wrap_width - (x - start_x));
-                if (word_wrap_eol == s) // Wrap_width is too small to fit anything. Force displaying 1 character to minimize the height discontinuity.
-                    word_wrap_eol++;    // +1 may not be a character start point in UTF-8 but it's ok because we use s >= word_wrap_eol below
-            }
 
             if (s >= word_wrap_eol)
             {
                 x = start_x;
                 y += line_height;
                 word_wrap_eol = NULL;
-
-                // Wrapping skips upcoming blanks
-                while (s < text_end)
-                {
-                    const char c = *s;
-                    if (ImCharIsBlankA(c)) { s++; } else if (c == '\n') { s++; break; } else { break; }
-                }
+                s = CalcWordWrapNextLineStartA(s, text_end); // Wrapping skips upcoming blanks
                 continue;
             }
         }