From 0b460bf4a17e12ba479e0822b8f9b7de29ac5816 Mon Sep 17 00:00:00 2001 From: PeterN Date: Thu, 29 Apr 2021 18:58:26 +0100 Subject: Fix: 'Cache' top and bottom lines of textfile viewer to avoid overdraw. (#9131) * Fix: 'Cache' top and bottom lines of textfile viewer to avoid overdraw. The text file viewer calculated the number of lines required to set the scrollbar, but did not retain this information, so this was recalculated on every draw operation. This includes overdrawing text outside the bounds of the current scroll position. With this change the top and bottom lines for each line of text are remembered, and reflowing is avoided where possible. Text outside the current scroll bounds is not drawn. Additionally the scroll interval is now based on text lines instead of pixel lines, which increases the text capacity depending on the font size. * Fix: Limit text viewer to showing 64k lines. Text files with more than 64k wrapped lines would exceed the scrollbar capacity and cause an assert. This is harder to reach now that the scrollbar counts lines instead of pixels. --- src/textfile_gui.cpp | 81 ++++++++++++++++++++++++++++++++++++---------------- src/textfile_gui.h | 16 +++++++++-- 2 files changed, 70 insertions(+), 27 deletions(-) diff --git a/src/textfile_gui.cpp b/src/textfile_gui.cpp index 075898fd7..ac8da5c2e 100644 --- a/src/textfile_gui.cpp +++ b/src/textfile_gui.cpp @@ -67,7 +67,6 @@ TextfileWindow::TextfileWindow(TextfileType file_type) : Window(&_textfile_desc) this->GetWidget(WID_TF_CAPTION)->SetDataTip(STR_TEXTFILE_README_CAPTION + file_type, STR_TOOLTIP_WINDOW_TITLE_DRAG_THIS); this->hscroll->SetStepSize(10); // Speed up horizontal scrollbar - this->vscroll->SetStepSize(FONT_HEIGHT_MONO); } /* virtual */ TextfileWindow::~TextfileWindow() @@ -79,23 +78,38 @@ TextfileWindow::TextfileWindow(TextfileType file_type) : Window(&_textfile_desc) * Get the total height of the content displayed in this window, if wrapping is disabled. * @return the height in pixels */ -uint TextfileWindow::GetContentHeight() +uint TextfileWindow::ReflowContent() { - int max_width = this->GetWidget(WID_TF_BACKGROUND)->current_x - WD_FRAMETEXT_LEFT - WD_FRAMERECT_RIGHT; - uint height = 0; - for (uint i = 0; i < this->lines.size(); i++) { - height += GetStringHeight(this->lines[i], max_width, FS_MONO); + if (!IsWidgetLowered(WID_TF_WRAPTEXT)) { + for (auto &line : this->lines) { + line.top = height; + height++; + line.bottom = height; + } + } else { + int max_width = this->GetWidget(WID_TF_BACKGROUND)->current_x - WD_FRAMETEXT_LEFT - WD_FRAMERECT_RIGHT; + for (auto &line : this->lines) { + line.top = height; + height += GetStringHeight(line.text, max_width, FS_MONO) / FONT_HEIGHT_MONO; + line.bottom = height; + } } return height; } +uint TextfileWindow::GetContentHeight() +{ + if (this->lines.size() == 0) return 0; + return this->lines.back().bottom; +} + /* virtual */ void TextfileWindow::UpdateWidgetSize(int widget, Dimension *size, const Dimension &padding, Dimension *fill, Dimension *resize) { switch (widget) { case WID_TF_BACKGROUND: - resize->height = 1; + resize->height = FONT_HEIGHT_MONO; size->height = 4 * resize->height + TOP_SPACING + BOTTOM_SPACING; // At least 4 lines are visible. size->width = std::max(200u, size->width); // At least 200 pixels wide. @@ -104,18 +118,17 @@ uint TextfileWindow::GetContentHeight() } /** Set scrollbars to the right lengths. */ -void TextfileWindow::SetupScrollbars() +void TextfileWindow::SetupScrollbars(bool force_reflow) { if (IsWidgetLowered(WID_TF_WRAPTEXT)) { - this->vscroll->SetCount(this->GetContentHeight()); + /* Reflow is mandatory if text wrapping is on */ + uint height = this->ReflowContent(); + this->vscroll->SetCount(std::min(UINT16_MAX, height)); this->hscroll->SetCount(0); } else { - uint max_length = 0; - for (uint i = 0; i < this->lines.size(); i++) { - max_length = std::max(max_length, GetStringBoundingBox(this->lines[i], FS_MONO).width); - } - this->vscroll->SetCount((uint)this->lines.size() * FONT_HEIGHT_MONO); - this->hscroll->SetCount(max_length + WD_FRAMETEXT_LEFT + WD_FRAMETEXT_RIGHT); + uint height = force_reflow ? this->ReflowContent() : this->GetContentHeight(); + this->vscroll->SetCount(std::min(UINT16_MAX, height)); + this->hscroll->SetCount(this->max_length + WD_FRAMETEXT_LEFT + WD_FRAMETEXT_RIGHT); } this->SetWidgetDisabledState(WID_TF_HSCROLLBAR, IsWidgetLowered(WID_TF_WRAPTEXT)); @@ -126,7 +139,6 @@ void TextfileWindow::SetupScrollbars() switch (widget) { case WID_TF_WRAPTEXT: this->ToggleWidgetLoweredState(WID_TF_WRAPTEXT); - this->SetupScrollbars(); this->InvalidateData(); break; } @@ -148,14 +160,18 @@ void TextfileWindow::SetupScrollbars() /* Draw content (now coordinates given to DrawString* are local to the new clipping region). */ int line_height = FONT_HEIGHT_MONO; - int y_offset = -this->vscroll->GetPosition(); + int pos = this->vscroll->GetPosition(); + int cap = this->vscroll->GetCapacity(); + + for (auto &line : this->lines) { + if (line.bottom < pos) continue; + if (line.top > pos + cap) break; - for (uint i = 0; i < this->lines.size(); i++) { + int y_offset = (line.top - pos) * line_height; if (IsWidgetLowered(WID_TF_WRAPTEXT)) { - y_offset = DrawStringMultiLine(0, right - x, y_offset, bottom - y, this->lines[i], TC_WHITE, SA_TOP | SA_LEFT, false, FS_MONO); + DrawStringMultiLine(0, right - x, y_offset, bottom - y, line.text, TC_WHITE, SA_TOP | SA_LEFT, false, FS_MONO); } else { - DrawString(-this->hscroll->GetPosition(), right - x, y_offset, this->lines[i], TC_WHITE, SA_TOP | SA_LEFT, false, FS_MONO); - y_offset += line_height; // margin to previous element + DrawString(-this->hscroll->GetPosition(), right - x, y_offset, line.text, TC_WHITE, SA_TOP | SA_LEFT, false, FS_MONO); } } @@ -167,7 +183,14 @@ void TextfileWindow::SetupScrollbars() this->vscroll->SetCapacityFromWidget(this, WID_TF_BACKGROUND, TOP_SPACING + BOTTOM_SPACING); this->hscroll->SetCapacityFromWidget(this, WID_TF_BACKGROUND); - this->SetupScrollbars(); + this->SetupScrollbars(false); +} + +/* virtual */ void TextfileWindow::OnInvalidateData(int data, bool gui_scope) +{ + if (!gui_scope) return; + + this->SetupScrollbars(true); } /* virtual */ void TextfileWindow::Reset() @@ -184,7 +207,7 @@ void TextfileWindow::SetupScrollbars() { if (this->search_iterator >= this->lines.size()) return nullptr; - return this->lines[this->search_iterator++]; + return this->lines[this->search_iterator++].text; } /* virtual */ bool TextfileWindow::Monospace() @@ -364,14 +387,22 @@ static void Xunzip(byte **bufp, size_t *sizep) str_validate(p, this->text + filesize, SVS_REPLACE_WITH_QUESTION_MARK | SVS_ALLOW_NEWLINE); /* Split the string on newlines. */ - this->lines.push_back(p); + int row = 0; + this->lines.emplace_back(row, p); for (; *p != '\0'; p++) { if (*p == '\n') { *p = '\0'; - this->lines.push_back(p + 1); + this->lines.emplace_back(++row, p + 1); } } + /* Calculate maximum text line length. */ + uint max_length = 0; + for (auto &line : this->lines) { + max_length = std::max(max_length, GetStringBoundingBox(line.text, FS_MONO).width); + } + this->max_length = max_length; + CheckForMissingGlyphs(true, this); } diff --git a/src/textfile_gui.h b/src/textfile_gui.h index d67435c01..5f1db14ca 100644 --- a/src/textfile_gui.h +++ b/src/textfile_gui.h @@ -19,13 +19,23 @@ const char *GetTextfile(TextfileType type, Subdirectory dir, const char *filenam /** Window for displaying a textfile */ struct TextfileWindow : public Window, MissingGlyphSearcher { + struct Line { + int top; ///< Top scroll position. + int bottom; ///< Bottom scroll position. + const char *text; ///< Pointer to text buffer. + + Line(int top, const char *text) : top(top), bottom(top + 1), text(text) {} + }; + TextfileType file_type; ///< Type of textfile to view. Scrollbar *vscroll; ///< Vertical scrollbar. Scrollbar *hscroll; ///< Horizontal scrollbar. char *text; ///< Lines of text from the NewGRF's textfile. - std::vector lines; ///< #text, split into lines in a table with lines. + std::vector lines; ///< #text, split into lines in a table with lines. uint search_iterator; ///< Iterator for the font check search. + uint max_length; ///< Maximum length of unwrapped text line. + static const int TOP_SPACING = WD_FRAMETEXT_TOP; ///< Additional spacing at the top of the #WID_TF_BACKGROUND widget. static const int BOTTOM_SPACING = WD_FRAMETEXT_BOTTOM; ///< Additional spacing at the bottom of the #WID_TF_BACKGROUND widget. @@ -36,6 +46,7 @@ struct TextfileWindow : public Window, MissingGlyphSearcher { void OnClick(Point pt, int widget, int click_count) override; void DrawWidget(const Rect &r, int widget) const override; void OnResize() override; + void OnInvalidateData(int data = 0, bool gui_scope = true) override; void Reset() override; FontSize DefaultSize() override; @@ -46,8 +57,9 @@ struct TextfileWindow : public Window, MissingGlyphSearcher { virtual void LoadTextfile(const char *textfile, Subdirectory dir); private: + uint ReflowContent(); uint GetContentHeight(); - void SetupScrollbars(); + void SetupScrollbars(bool force_reflow); }; #endif /* TEXTFILE_GUI_H */ -- cgit v1.2.3-70-g09d2