[WIP] Grid system refactor.

TODO.md

@@ -1,7 +1,7 @@
-# Current PR (box drawings)
+# Current PR
+
+- [ ] maxHistoryLineCount cannot be "unlimited" anymore.
 
-- [ ] `builtin_box_drawing: false` ignored? check!
-- [ ]  top-left and bottom-left arc show artifacts on very left side. why? most likely overflow in pixel painting.
 
 # RELEASE CHECKLIST
 

autogen.sh

@@ -29,5 +29,5 @@ exec cmake "${ROOTDIR}" \
            -DCONTOUR_COVERAGE="OFF" \
            -DCONTOUR_PERF_STATS="ON" \
            -DCONTOUR_BLUR_PLATFORM_KWIN="ON" \
-           -GNinja
+           #-GNinja
 

docs/grid-redesign.md

@@ -0,0 +1,89 @@
+# Grid (re)design
+
+## grid properties
+
+- line and column positions are given in offsets (0-based indices!)
+- grid cells of the full scrollback + main page area are stored in dense linear space
+- `Line` is just a view into the ring buffer
+- logical lines above main page area's line count cannot be edited
+- scroll offset represents the *bottom* line of the viewport.
+- maybe make scroll offset negative (to have all ops being additions)
+
+## corollary
+
+- the VT screen line/column position to offset translation (minus 1)
+  happens as early as possible in the `Sequencer`.
+- `Line::Wrapped`-flag can be removed.
+- writing an overlong line does not need to care about auto-wrapping
+  - because `lineLength / pageWidth == numberOfLinesWriten`
+  - the new cursor position can be computed analogous to the above
+- because of the meaning of the scroll-offset, reflow can be O(1) implemented
+  with a `Line()` being arbitrary long(!) and the top screen line being
+  computed by subtracting `(PageLineCount - 1) * PageColumnCount)`,
+  then *just* lineary walking forward until the bottom right.
+  - this enables relative jumps (`CUU` etc) to jump up logical lines.
+  - we could make the cursor jump behavior configurable, via DEC mode.
+- On char write overflow
+  - if Reflow DEC mode is enabled, then continue appending character
+  - else if AutoWrap DEC mode is enabled, then linefeed()
+  - else overwrite character on right margin
+- I think with the above approach we do not need DEC mode 2027 for disabling
+  reflow in order to protect command prompts. as they're automatically protected
+  by the grid line architecture.
+
+### Notes
+
+Suppose only a single overly long line is written and ocupies the full screen
+(many page counts).
+
+```
+bottomRightOffset = line(cursor.line + realOffset(scrollOffset_)).right_offset;
+topLeftOffset = bottomRightOffset - pageSize.lines * pageSize.columns;
+
+def renderViewport():
+{
+    for (auto i = topLeftOffset, k = 0; i < bottomRightOffset; ++i, ++k)
+    {
+        auto rowNr = k / pageSize.columns;
+        auto colNr = k % pageSize.columns;
+        renderCell(buffer_[i], rowNr, colNr);
+    }
+}
+```
+
+## shrink columns
+
+    page size: 6x2
+    lines: 2
+    line.1: 0..5        abcdef
+    line.2: 6..11       ABCDEF
+
+    shrink to pageSize: 4x2
+
+    line.1:  0..3       abcd
+    line.2:  4..5       ef      Wrapped
+    line.3:  6..9       ABCD
+    line.4: 10..11      EF      Wrapped
+
+Shrinking does not destroy, as it always reflows.
+`CUU` will move by logical line numbers.
+
+## overlong lines
+
+4x2
+
+
+    line.1 ABCDEFabcdef
+    line.2 ABCD
+
+    view:
+
+        history.line.-1 ABCD
+        history.line.0  EFAB
+        logical.line.1  cdef
+        logical.line.2  ABCD
+
+## Rendering a wrapped line
+
+- the scroll-offset represents the number of real lines scrolled up
+-

src/contour/Config.cpp

@@ -1181,10 +1181,10 @@ TerminalProfile loadTerminalProfile(UsedKeys& _usedKeys,
     else
         errorlog().write("Invalid render_mode \"{}\" in configuration.", renderModeStr);
 
-    auto intValue = profile.maxHistoryLineCount.value_or(std::numeric_limits<LineCount>::max());
+    auto intValue = profile.maxHistoryLineCount;
     tryLoadChild(_usedKeys, _doc, basePath, "history.limit", intValue);
-    if (unbox<int>(intValue) < 0 || intValue == std::numeric_limits<LineCount>::max())
-        profile.maxHistoryLineCount = nullopt;
+    if (unbox<int>(intValue) < 0)
+        profile.maxHistoryLineCount = LineCount(0);
     else
         profile.maxHistoryLineCount = intValue;
 

src/contour/Config.h

@@ -127,7 +127,7 @@ struct TerminalProfile {
     terminal::PageSize terminalSize = {terminal::LineCount(10), terminal::ColumnCount(40)};
     terminal::VTType terminalId = terminal::VTType::VT525;
 
-    std::optional<terminal::LineCount> maxHistoryLineCount;
+    terminal::LineCount maxHistoryLineCount;
     terminal::LineCount historyScrollMultiplier;
     ScrollBarPosition scrollbarPosition = ScrollBarPosition::Right;
     bool hideScrollbarInAltScreen = true;

src/contour/TerminalSession.cpp

@@ -490,7 +490,7 @@ void TerminalSession::operator()(actions::FollowHyperlink)
     auto const _l = scoped_lock{terminal()};
     auto const currentMousePosition = terminal().currentMousePosition();
     auto const currentMousePositionRel = terminal::Coordinate{
-        currentMousePosition.row - terminal().viewport().relativeScrollOffset().as<int>(),
+        currentMousePosition.row + terminal().viewport().scrollOffset().as<LineOffset>(),
         currentMousePosition.column
     };
     if (terminal().screen().contains(currentMousePosition))

src/contour/TerminalWindow.cpp

@@ -124,8 +124,8 @@ void ScrollableDisplay::updateValues()
         return;
 
     scrollBar_->setMaximum(session_.terminal().screen().historyLineCount().as<int>());
-    if (auto const s = session_.terminal().viewport().absoluteScrollOffset(); s.has_value())
-        scrollBar_->setValue(s.value().as<int>());
+    if (auto const s = session_.terminal().viewport().scrollOffset(); s.value)
+        scrollBar_->setValue(s.value);
     else
         scrollBar_->setValue(scrollBar_->maximum());
 }
@@ -196,7 +196,7 @@ void ScrollableDisplay::updatePosition()
 
 void ScrollableDisplay::onValueChanged()
 {
-    session_.terminal().viewport().scrollToAbsolute(terminal::StaticScrollbackPosition(scrollBar_->value()));
+    session_.terminal().viewport().scrollTo(terminal::ScrollOffset::cast_from(scrollBar_->value()));
     session_.scheduleRedraw();
 }
 #endif // }}}

src/contour/opengl/TerminalWidget.cpp

@@ -1090,7 +1090,7 @@ void TerminalWidget::assertInitialized()
 
 void TerminalWidget::onScrollBarValueChanged(int _value)
 {
-    terminal().viewport().scrollToAbsolute(terminal::StaticScrollbackPosition::cast_from(_value));
+    terminal().viewport().scrollTo(terminal::ScrollOffset::cast_from(_value));
     scheduleRedraw();
 }
 

src/crispy/boxed.h

@@ -86,10 +86,10 @@ template <typename T, typename Tag> struct boxed
     }
 };
 
-template <typename T, typename U> constexpr T& operator++(boxed<T, U>& a) noexcept { ++a.value; return a; }
-template <typename T, typename U> constexpr T& operator++(boxed<T, U>& a, int) noexcept { a.value++; return a; }
-template <typename T, typename U> constexpr T& operator--(boxed<T, U>& a) noexcept { --a.value; return a; }
-template <typename T, typename U> constexpr T& operator--(boxed<T, U>& a, int) noexcept { a.value--; return a; }
+template <typename T, typename U> constexpr boxed<T, U>& operator++(boxed<T, U>& a) noexcept { ++a.value; return a; }
+template <typename T, typename U> constexpr boxed<T, U>& operator++(boxed<T, U>& a, int) noexcept { a.value++; return a; }
+template <typename T, typename U> constexpr boxed<T, U>& operator--(boxed<T, U>& a) noexcept { --a.value; return a; }
+template <typename T, typename U> constexpr boxed<T, U>& operator--(boxed<T, U>& a, int) noexcept { a.value--; return a; }
 template <typename T, typename U> constexpr T const& operator*(boxed<T, U> const& a) noexcept { return a.value; }
 template <typename T, typename U> constexpr bool operator<(boxed<T, U> const& a, boxed<T, U> const& b) noexcept { return a.value < b.value; }
 template <typename T, typename U> constexpr bool operator>(boxed<T, U> const& a, boxed<T, U> const& b) noexcept { return a.value > b.value; }
@@ -102,6 +102,10 @@ template <typename T, typename U> constexpr boxed<T, U> operator+(boxed<T, U> co
 template <typename T, typename U> constexpr boxed<T, U> operator-(boxed<T, U> const& a, boxed<T, U> const& b) noexcept { return boxed<T, U>{a.value - b.value}; }
 template <typename T, typename U> constexpr boxed<T, U> operator*(boxed<T, U> const& a, boxed<T, U> const& b) noexcept { return boxed<T, U>{a.value * b.value}; }
 template <typename T, typename U> constexpr boxed<T, U> operator/(boxed<T, U> const& a, boxed<T, U> const& b) noexcept { return boxed<T, U>{a.value / b.value}; }
+template <typename T, typename U> constexpr boxed<T, U> operator%(boxed<T, U> const& a, boxed<T, U> const& b) noexcept { return boxed<T, U>{a.value % b.value}; }
+
+template <typename T, typename U> constexpr boxed<T, U> operator-(boxed<T, U> const& a) noexcept { return boxed<T, U>{-a.value}; }
+template <typename T, typename U> constexpr boxed<T, U> operator+(boxed<T, U> const& a) noexcept { return boxed<T, U>{+a.value}; }
 
 template <typename T, typename U> constexpr boxed<T, U> operator+(boxed<T, U> const& a, T b) noexcept { return boxed<T, U>{a.value + b}; }
 template <typename T, typename U> constexpr boxed<T, U> operator-(boxed<T, U> const& a, T b) noexcept { return boxed<T, U>{a.value - b}; }
@@ -112,6 +116,7 @@ template <typename T, typename U> constexpr boxed<T, U>& operator+=(boxed<T, U>&
 template <typename T, typename U> constexpr boxed<T, U>& operator-=(boxed<T, U>& a, boxed<T, U> const& b) noexcept { a.value -= b.value; return a; }
 template <typename T, typename U> constexpr boxed<T, U>& operator*=(boxed<T, U>& a, boxed<T, U> const& b) noexcept { a.value *= b.value; return a; }
 template <typename T, typename U> constexpr boxed<T, U>& operator/=(boxed<T, U>& a, boxed<T, U> const& b) noexcept { a.value /= b.value; return a; }
+template <typename T, typename U> constexpr boxed<T, U>& operator%=(boxed<T, U>& a, boxed<T, U> const& b) noexcept { a.value %= b.value; return a; }
 
 template <typename T, typename U> std::ostream& operator<<(std::ostream& os, boxed<T, U> const& v) { return os << v.value; }
 

src/terminal/CMakeLists.txt

@@ -61,6 +61,7 @@ set(terminal_SOURCES
     Capabilities.cpp
     Color.cpp
     Grid.cpp
+    Screen.cpp # TODO(pr) move back. only moved here for test-compiles
     Functions.cpp
     Image.cpp
     InputBinding.cpp
@@ -69,7 +70,7 @@ set(terminal_SOURCES
     Parser.cpp
     Process.cpp
     RenderBuffer.cpp
-    Screen.cpp
+    #Screen.cpp
     Sequence.cpp
     Sequencer.cpp
     Selector.cpp

src/terminal/Charset.h

@@ -39,11 +39,23 @@ class CharsetMapping {
         }
     {}
 
-    char32_t map(char _code) noexcept
+    char32_t map(char32_t _code) noexcept
     {
-        auto result = map(shift_, _code);
-        shift_ = selected_;
-        return result;
+        // TODO: could surely be implemented branchless with a jump-table and computed goto.
+        if (_code < 127)
+        {
+            auto result = map(shift_, static_cast<char>(_code));
+            shift_ = selected_;
+            return result;
+        }
+        else if (_code != 127)
+        {
+            return static_cast<char32_t>(_code);
+        }
+        else
+        {
+            return L' ';
+        }
     }
 
     char32_t map(CharsetTable _table, char _code) const noexcept

src/terminal/Coordinate.h

@@ -13,41 +13,39 @@
  */
 #pragma once
 
-#include <crispy/point.h>
+#include <terminal/primitives.h>
+#include <ostream>
 
 namespace terminal {
 
 struct [[nodiscard]] Coordinate {
-    int row = 0;
-    int column = 0;
+    LineOffset row{};
+    ColumnOffset column{};
 
-    constexpr Coordinate& operator+=(Coordinate const& a) noexcept
+    constexpr Coordinate& operator+=(Coordinate a) noexcept
     {
         row += a.row;
         column += a.column;
         return *this;
     }
-
-    constexpr Coordinate(int _row, int _column) : row{_row}, column{_column} {}
-    constexpr explicit Coordinate(crispy::Point p) : row{p.y}, column{p.x} {}
-    constexpr Coordinate() = default;
-    constexpr Coordinate(Coordinate const&) = default;
-    constexpr Coordinate(Coordinate&& v) = default;
-    constexpr Coordinate& operator=(Coordinate const&) = default;
-    constexpr Coordinate& operator=(Coordinate &&) = default;
 };
 
+inline std::ostream& operator<<(std::ostream& os, Coordinate coord)
+{
+    return os << fmt::format("({}, {})", coord.row, coord.column);
+}
+
 constexpr void swap(Coordinate& a, Coordinate& b) noexcept
 {
     auto c = a;
     a = b;
     b = c;
 }
 
-constexpr bool operator==(Coordinate const& a, Coordinate const& b) noexcept { return a.row == b.row && a.column == b.column; }
-constexpr bool operator!=(Coordinate const& a, Coordinate const& b) noexcept { return !(a == b); }
+constexpr bool operator==(Coordinate a, Coordinate b) noexcept { return a.row == b.row && a.column == b.column; }
+constexpr bool operator!=(Coordinate a, Coordinate b) noexcept { return !(a == b); }
 
-constexpr bool operator<(Coordinate const& a, Coordinate const& b) noexcept
+constexpr bool operator<(Coordinate a, Coordinate b) noexcept
 {
     if (a.row < b.row)
         return true;
@@ -58,27 +56,22 @@ constexpr bool operator<(Coordinate const& a, Coordinate const& b) noexcept
     return false;
 }
 
-constexpr bool operator<=(Coordinate const& a, Coordinate const& b) noexcept
+constexpr bool operator<=(Coordinate a, Coordinate b) noexcept
 {
     return a < b || a == b;
 }
 
-constexpr bool operator>=(Coordinate const& a, Coordinate const& b) noexcept
+constexpr bool operator>=(Coordinate a, Coordinate b) noexcept
 {
     return !(a < b);
 }
 
-constexpr bool operator>(Coordinate const& a, Coordinate const& b) noexcept
+constexpr bool operator>(Coordinate a, Coordinate b) noexcept
 {
     return !(a == b || a < b);
 }
 
-inline Coordinate operator+(Coordinate const& a, Coordinate const& b) noexcept { return {a.row + b.row, a.column + b.column}; }
-
-constexpr Coordinate operator+(Coordinate const& a, crispy::Point b) noexcept
-{
-    return {a.row + b.y, a.column + b.x};
-}
+inline Coordinate operator+(Coordinate a, Coordinate b) noexcept { return {a.row + b.row, a.column + b.column}; }
 
 }
 
@@ -97,3 +90,4 @@ namespace fmt {
         }
     };
 }
+