InputText, ImDrawList: Fixed assert triggering when drawing single line of text with more than ~16 KB characters. (#3349)
diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
index 6ee96d7..0264e31 100644
--- a/docs/CHANGELOG.txt
+++ b/docs/CHANGELOG.txt
@@ -37,6 +37,11 @@
Other Changes:
+- InputText, ImDrawList: Fixed assert triggering when drawing single line of text with more
+ than ~16 KB characters. (Note that current code is going to show corrupted display if after
+ clipping, more than 16 KB characters are visible in the same low-level ImDrawList::RenderText
+ call. ImGui-level functions such as TextUnformatted() are not affected. This is quite rare
+ but it will be addressed later). (#3349)
- ImDrawList: Thick anti-aliased strokes (> 1.0f) with integer thickness now use a texture-based
path, reducing the amount of vertices/indices and CPU/GPU usage. (#3245) [@Shironekoben]
- This change will facilitate the wider use of thick borders in future style changes.
diff --git a/docs/TODO.txt b/docs/TODO.txt
index abb9d51..9502e26 100644
--- a/docs/TODO.txt
+++ b/docs/TODO.txt
@@ -308,7 +308,8 @@
- font/atlas: dynamic font atlas to avoid baking huge ranges into bitmap and make scaling easier.
- font/draw: vertical and/or rotated text renderer (#705) - vertical is easier clipping wise
- font/draw: need to be able to specify wrap start position.
- - font/draw: better reserve policy for large horizontal block of text (shouldn't reserve for all clipped lines)
+ - font/draw: better reserve policy for large horizontal block of text (shouldn't reserve for all clipped lines). also see #3349.
+ - font/draw: fix for drawing 16k+ visible characters in same call.
- font/draw: underline, squiggle line rendering helpers.
- font: optimization: for monospace font (like the default one) we can trim IndexXAdvance as long as trailing value is == FallbackXAdvance (need to make sure TAB is still correct), would save on cache line.
- font: add support for kerning, probably optional. A) perhaps default to (32..128)^2 matrix ~ 9K entries = 36KB, then hash for non-ascii?. B) or sparse lookup into per-char list?
diff --git a/imgui_draw.cpp b/imgui_draw.cpp
index 864364e..09b5a41 100644
--- a/imgui_draw.cpp
+++ b/imgui_draw.cpp
@@ -517,7 +517,7 @@
// We don't need to compare curr_cmd->VtxOffset != _CmdHeader.VtxOffset because we know it'll be different at the time we call this.
_VtxCurrentIdx = 0;
ImDrawCmd* curr_cmd = &CmdBuffer.Data[CmdBuffer.Size - 1];
- IM_ASSERT(curr_cmd->VtxOffset != _CmdHeader.VtxOffset);
+ //IM_ASSERT(curr_cmd->VtxOffset != _CmdHeader.VtxOffset); // See #3349
if (curr_cmd->ElemCount != 0)
{
AddDrawCmd();
@@ -582,6 +582,9 @@
IM_ASSERT_PARANOID(idx_count >= 0 && vtx_count >= 0);
if (sizeof(ImDrawIdx) == 2 && (_VtxCurrentIdx + vtx_count >= (1 << 16)) && (Flags & ImDrawListFlags_AllowVtxOffset))
{
+ // FIXME: In theory we should be testing that vtx_count <64k here.
+ // In practice, RenderText() relies on reserving ahead for a worst case scenario so it is currently useful for us
+ // to not make that check until we rework the text functions to handle clipping and large horizontal lines better.
_CmdHeader.VtxOffset = VtxBuffer.Size;
_OnChangedVtxOffset();
}
