Cursor movement, draw selection and fixing bugs

src/text_editor/buffer.cpp

@@ -9,6 +9,12 @@ void InitBuffer(Allocator allocator, Buffer *buffer) {
     Add(&buffer->line_starts, (Int)0);
 }
 
+Buffer *CreateBuffer(Allocator allocator) {
+    Buffer *result = AllocType(allocator, Buffer);
+    InitBuffer(allocator, result);
+    return result;
+}
+
 void Grow(Buffer *buffer, Int change_size) {
     Int new_size = buffer->len + change_size;
     if (new_size > buffer->cap) {
@@ -33,16 +39,44 @@ void OffsetAllLinesForward(Buffer *buffer, Int line, Int *_offset) {
     }
 }
 
+Int LastLine(Buffer &buffer) {
+    Int result = buffer.line_starts.len - 1;
+    return result;
+}
+
+const Int LAST_LINE = INT64_MAX;
 Range     GetLine(Buffer &buffer, Int line) {
-    Range result = {0, buffer.len};
+    Range result = {buffer.line_starts[line], buffer.len};
-    result.min   = buffer.line_starts[line];
+    if (line + 1 < buffer.line_starts.len) {
-    if (buffer.line_starts.len < line + 1) {
         result.max = buffer.line_starts[line + 1];
     }
     return result;
 }
 
-Int GetLineNumber(Buffer &buffer, Int pos) {
+Int CalculateLongestLine(Buffer &buffer) {
+    // @optimize: this needs to be cached and then only updated when
+    // we modify the buffer. Maybe some modification ID or something.
+    Int index_max = 0;
+    Int size_max  = 0;
+    for (Int i = 0; i < buffer.line_starts.len; i += 1) {
+        Range range = GetLine(buffer, i);
+        Int   size  = GetSize(range);
+        if (size > size_max) {
+            index_max = i;
+            size_max  = size;
+        }
+    }
+    return index_max;
+}
+
+Int GetCharCountOfLongestLine(Buffer &buffer) {
+    Int   line   = CalculateLongestLine(buffer);
+    Range range  = GetLine(buffer, line);
+    Int   result = GetSize(range);
+    return result;
+}
+
+Int PosToLine(Buffer &buffer, Int pos) {
     Add(&buffer.line_starts, buffer.len + 1);
 
     // binary search
@@ -69,10 +103,25 @@ Int GetLineNumber(Buffer &buffer, Int pos) {
     return result;
 }
 
+XY PosToXY(Buffer &buffer, Int pos) {
+    Int   line       = PosToLine(buffer, pos);
+    Range line_range = GetLine(buffer, line);
+    Int   col        = pos - line_range.min;
+    XY    result     = {col, line};
+    return result;
+}
+
+Int XYToPos(Buffer &buffer, XY xy) {
+    xy.line          = Clamp(xy.line, (Int)0, buffer.line_starts.len - 1);
+    Range line_range = GetLine(buffer, xy.line);
+    Int   pos        = Clamp(xy.col + line_range.min, line_range.min, line_range.max);
+    return pos;
+}
+
 void ValidateLineStarts(Buffer *buffer) {
     Int line = 0;
     for (Int i = 0; i < buffer->len; i += 1) {
-        Int l = GetLineNumber(*buffer, i);
+        Int l = PosToLine(*buffer, i);
         Assert(l == line);
         if (buffer->data[i] == L'\n') line += 1;
     }
@@ -80,7 +129,7 @@ void ValidateLineStarts(Buffer *buffer) {
 
 void UpdateLines(Buffer *buffer, Range range, String16 string) {
     Array<Int> &ls              = buffer->line_starts;
-    Int         min_line_number = GetLineNumber(*buffer, range.min);
+    Int         min_line_number = PosToLine(*buffer, range.min);
     Assert(min_line_number < ls.len);
     // Update lines remove
     {
@@ -161,7 +210,7 @@ void TestBuffer() {
             Assert(a == test_string);
             Assert(buffer.line_starts.len == 1);
             Assert(buffer.line_starts[0] == 0);
-            Assert(GetLineNumber(buffer, 4) == 0);
+            Assert(PosToLine(buffer, 4) == 0);
         }
         {
             ReplaceText(&buffer, {0, 5}, L"");
@@ -171,7 +220,7 @@ void TestBuffer() {
             Assert(a == L" itself");
             Assert(buffer.line_starts.len == 1);
             Assert(buffer.line_starts[0] == 0);
-            Assert(GetLineNumber(buffer, 4) == 0);
+            Assert(PosToLine(buffer, 4) == 0);
         }
         {
             ReplaceText(&buffer, GetEndAsRange(buffer), L" and");
@@ -181,7 +230,7 @@ void TestBuffer() {
             Assert(a == L" itself and");
             Assert(buffer.line_starts.len == 1);
             Assert(buffer.line_starts[0] == 0);
-            Assert(GetLineNumber(buffer, 4) == 0);
+            Assert(PosToLine(buffer, 4) == 0);
         }
         {
             ReplaceText(&buffer, GetRange(buffer), L"");
@@ -195,31 +244,31 @@ void TestBuffer() {
         {
             ReplaceText(&buffer, GetEndAsRange(buffer), L"Memes and other\nthings");
             Assert(buffer.line_starts.len == 2);
-            Assert(GetLineNumber(buffer, 17) == 1);
+            Assert(PosToLine(buffer, 17) == 1);
-            Assert(GetLineNumber(buffer, 16) == 1);
+            Assert(PosToLine(buffer, 16) == 1);
-            Assert(GetLineNumber(buffer, 15) == 0);
+            Assert(PosToLine(buffer, 15) == 0);
             Assert(buffer.data[15] == L'\n');
             Assert(buffer.data[16] == L't');
 
             ReplaceText(&buffer, GetBeginAsRange(buffer), L"Things as is\nand stuff\n");
             Assert(buffer.line_starts.len == 4);
-            Assert(GetLineNumber(buffer, 12) == 0);
+            Assert(PosToLine(buffer, 12) == 0);
             Assert(buffer.data[12] == L'\n');
-            Assert(GetLineNumber(buffer, 13) == 1);
+            Assert(PosToLine(buffer, 13) == 1);
-            Assert(GetLineNumber(buffer, 21) == 1);
+            Assert(PosToLine(buffer, 21) == 1);
-            Assert(GetLineNumber(buffer, 22) == 1);
+            Assert(PosToLine(buffer, 22) == 1);
             Assert(buffer.data[22] == L'\n');
-            Assert(GetLineNumber(buffer, 23) == 2);
+            Assert(PosToLine(buffer, 23) == 2);
-            Assert(GetLineNumber(buffer, 37) == 2);
+            Assert(PosToLine(buffer, 37) == 2);
-            Assert(GetLineNumber(buffer, 38) == 2);
+            Assert(PosToLine(buffer, 38) == 2);
             Assert(buffer.data[38] == L'\n');
-            Assert(GetLineNumber(buffer, 39) == 3);
+            Assert(PosToLine(buffer, 39) == 3);
             Assert(buffer.data[39] == L't');
 
             ReplaceText(&buffer, GetBeginAsRange(buffer), L"a");
             Assert(buffer.line_starts.len == 4);
-            Assert(GetLineNumber(buffer, 13) == 0);
+            Assert(PosToLine(buffer, 13) == 0);
-            Assert(GetLineNumber(buffer, 14) == 1);
+            Assert(PosToLine(buffer, 14) == 1);
         }
     }
 
@@ -227,11 +276,11 @@ void TestBuffer() {
         Buffer buffer = {};
         InitBuffer(scratch, &buffer);
         ReplaceText(&buffer, {}, L"Thing\nmeme");
-        Assert(GetLineNumber(buffer, 5) == 0);
+        Assert(PosToLine(buffer, 5) == 0);
-        Assert(GetLineNumber(buffer, 6) == 1);
+        Assert(PosToLine(buffer, 6) == 1);
         ReplaceText(&buffer, {0, 1}, L"");
-        Assert(GetLineNumber(buffer, 4) == 0);
+        Assert(PosToLine(buffer, 4) == 0);
-        Assert(GetLineNumber(buffer, 5) == 1);
+        Assert(PosToLine(buffer, 5) == 1);
         ReplaceText(&buffer, {4, 5}, L"");
         Assert(buffer.line_starts.len == 1);
         ValidateLineStarts(&buffer);
@@ -243,8 +292,8 @@ void TestBuffer() {
         ReplaceText(&buffer, {}, L"Thing\nmeme");
         ReplaceText(&buffer, {0, 5}, L"per\ncop");
         Assert(buffer.line_starts.len == (Int)3);
-        Assert(GetLineNumber(buffer, 3) == 0);
+        Assert(PosToLine(buffer, 3) == 0);
-        Assert(GetLineNumber(buffer, 4) == 1);
+        Assert(PosToLine(buffer, 4) == 1);
         ValidateLineStarts(&buffer);
 
         ReplaceText(&buffer, {0, 8}, L"Thing\nmeme");

src/text_editor/buffer.h

@@ -21,9 +21,9 @@ struct Cursor {
     Int ifront;
 };
 
-struct Pos {
+struct XY {
-    Int line;
     Int col;
+    Int line;
 };
 
 struct Edit {

src/text_editor/buffer_helpers.cpp

@@ -104,3 +104,14 @@ bool InRange(Int a, Range b) {
     bool result = a >= b.min && a < b.max;
     return result;
 }
+
+Range operator-(Range a, Int value) {
+    a.min -= value;
+    a.max -= value;
+    return a;
+}
+
+Range operator-=(Range &range, Int value) {
+    range = range - value;
+    return range;
+}

src/text_editor/math.cpp

@@ -0,0 +1,146 @@
+struct Vec2 {
+    float x;
+    float y;
+};
+
+struct Vec2I {
+    Int x;
+    Int y;
+};
+
+struct Rect2 {
+    Vec2 min;
+    Vec2 max;
+};
+
+struct Rect2I {
+    Vec2I min;
+    Vec2I max;
+};
+
+Vec2 GetSize(Rect2 r) {
+    Vec2 result = {r.max.x - r.min.x, r.max.y - r.min.y};
+    return result;
+}
+
+// clang-format off
+Rect2 operator-(Rect2 r, Rect2 value) { return { r.min.x - value.min.x, r.min.y - value.min.y, r.max.x - value.max.x, r.max.y - value.max.y }; }
+Rect2 operator+(Rect2 r, Rect2 value) { return { r.min.x + value.min.x, r.min.y + value.min.y, r.max.x + value.max.x, r.max.y + value.max.y }; }
+Rect2 operator*(Rect2 r, Rect2 value) { return { r.min.x * value.min.x, r.min.y * value.min.y, r.max.x * value.max.x, r.max.y * value.max.y }; }
+Rect2 operator/(Rect2 r, Rect2 value) { return { r.min.x / value.min.x, r.min.y / value.min.y, r.max.x / value.max.x, r.max.y / value.max.y }; }
+
+Rect2 operator-(Rect2 r, Vec2 value) { return { r.min.x - value.x, r.min.y - value.y, r.max.x - value.x, r.max.y - value.y }; }
+Rect2 operator+(Rect2 r, Vec2 value) { return { r.min.x + value.x, r.min.y + value.y, r.max.x + value.x, r.max.y + value.y }; }
+Rect2 operator*(Rect2 r, Vec2 value) { return { r.min.x * value.x, r.min.y * value.y, r.max.x * value.x, r.max.y * value.y }; }
+Rect2 operator/(Rect2 r, Vec2 value) { return { r.min.x / value.x, r.min.y / value.y, r.max.x / value.x, r.max.y / value.y }; }
+
+Rect2 operator-(Rect2 r, float value) { return { r.min.x - value, r.min.y - value, r.max.x - value, r.max.y - value }; }
+Rect2 operator+(Rect2 r, float value) { return { r.min.x + value, r.min.y + value, r.max.x + value, r.max.y + value }; }
+Rect2 operator*(Rect2 r, float value) { return { r.min.x * value, r.min.y * value, r.max.x * value, r.max.y * value }; }
+Rect2 operator/(Rect2 r, float value) { return { r.min.x / value, r.min.y / value, r.max.x / value, r.max.y / value }; }
+
+Rect2 operator-=(Rect2 &r, Rect2 value) { r = r - value; return r; }
+Rect2 operator+=(Rect2 &r, Rect2 value) { r = r + value; return r; }
+Rect2 operator*=(Rect2 &r, Rect2 value) { r = r * value; return r; }
+Rect2 operator/=(Rect2 &r, Rect2 value) { r = r / value; return r; }
+Rect2 operator-=(Rect2 &r, Vec2 value) { r = r - value; return r; }
+Rect2 operator+=(Rect2 &r, Vec2 value) { r = r + value; return r; }
+Rect2 operator*=(Rect2 &r, Vec2 value) { r = r * value; return r; }
+Rect2 operator/=(Rect2 &r, Vec2 value) { r = r / value; return r; }
+Rect2 operator-=(Rect2 &r, float value) { r = r - value; return r; }
+Rect2 operator+=(Rect2 &r, float value) { r = r + value; return r; }
+Rect2 operator*=(Rect2 &r, float value) { r = r * value; return r; }
+Rect2 operator/=(Rect2 &r, float value) { r = r / value; return r; }
+
+Vec2 operator-(Vec2 a, Vec2 b) { return {a.x - b.x, a.y - b.y}; }
+Vec2 operator+(Vec2 a, Vec2 b) { return {a.x + b.x, a.y + b.y}; }
+Vec2 operator*(Vec2 a, Vec2 b) { return {a.x * b.x, a.y * b.y}; }
+Vec2 operator/(Vec2 a, Vec2 b) { return {a.x / b.x, a.y / b.y}; }
+
+Vec2 operator-(Vec2 a, float b) { return {a.x - b, a.y - b}; }
+Vec2 operator+(Vec2 a, float b) { return {a.x + b, a.y + b}; }
+Vec2 operator*(Vec2 a, float b) { return {a.x * b, a.y * b}; }
+Vec2 operator/(Vec2 a, float b) { return {a.x / b, a.y / b}; }
+
+Vec2 operator-=(Vec2 &a, Vec2 b) { a = a - b; return a; }
+Vec2 operator+=(Vec2 &a, Vec2 b) { a = a + b; return a; }
+Vec2 operator*=(Vec2 &a, Vec2 b) { a = a * b; return a; }
+Vec2 operator/=(Vec2 &a, Vec2 b) { a = a / b; return a; }
+Vec2 operator-=(Vec2 &a, float b) { a = a - b; return a; }
+Vec2 operator+=(Vec2 &a, float b) { a = a + b; return a; }
+Vec2 operator*=(Vec2 &a, float b) { a = a * b; return a; }
+Vec2 operator/=(Vec2 &a, float b) { a = a / b; return a; }
+
+// clang-format on
+
+Rect2 Rect2FromSize(Vec2 pos, Vec2 size) {
+    Rect2 result = {};
+    result.min   = pos;
+    result.max   = pos + size;
+    return result;
+}
+
+Rect2 Shrink(Rect2 result, float v) {
+    result.min.x += v;
+    result.max.x -= v;
+    result.min.y += v;
+    result.max.y -= v;
+    return result;
+}
+
+Vec2 GetMid(Rect2 r) {
+    Vec2 size = GetSize(r);
+    size.x /= 2.f;
+    size.y /= 2.f;
+    Vec2 result = r.min + size;
+    return result;
+}
+
+Rect2 CutLeft(Rect2 *r, float value) {
+    float minx   = r->min.x;
+    r->min.x     = Min(r->min.x + value, r->max.x);
+    Rect2 result = {
+        {    minx, r->min.y},
+        {r->min.x, r->max.y}
+    };
+    return result;
+}
+
+Rect2 CutRight(Rect2 *r, float value) {
+    float maxx   = r->max.x;
+    r->max.x     = Max(r->min.x, r->max.x - value);
+    Rect2 result = {
+        {r->max.x, r->min.y},
+        {    maxx, r->max.y},
+    };
+    return result;
+}
+
+// Y is up
+Rect2 CutBottom(Rect2 *r, float value) {
+    float maxy   = r->max.y;
+    r->max.y     = Max(r->min.y, r->max.y - value);
+    Rect2 result = {
+        {r->min.x, r->max.y},
+        {r->max.x,     maxy},
+    };
+    return result;
+}
+
+// Y is up
+Rect2 CutTop(Rect2 *r, float value) {
+    float miny   = r->min.y;
+    r->min.y     = Min(r->min.y + value, r->max.y);
+    Rect2 result = {
+        {r->min.x,     miny},
+        {r->max.x, r->min.y},
+    };
+    return result;
+}
+
+float SafeDivide(float a, float b) {
+    if (b == 0.f) {
+        return 0.f;
+    }
+    return a / b;
+}

src/text_editor/raylib_utils.cpp

@@ -0,0 +1,69 @@
+Rectangle ToRectangle(Rect2 r) {
+    Rectangle result = {r.min.x, r.min.y, r.max.x - r.min.x, r.max.y - r.min.y};
+    return result;
+}
+
+Rect2 GetScreenRect() {
+    Rect2 result = {0, 0, (float)GetRenderWidth(), (float)GetRenderHeight()};
+    return result;
+}
+
+float GetCharSpacing(Font font, float font_size, float spacing) {
+    int index = GetGlyphIndex(font, '_');
+
+    float textOffsetX = 0;
+    float scaleFactor = font_size / font.baseSize; // Character quad scaling factor
+    if (font.glyphs[index].advanceX == 0) textOffsetX += ((float)font.recs[index].width * scaleFactor + spacing);
+    else textOffsetX += ((float)font.glyphs[index].advanceX * scaleFactor + spacing);
+    return textOffsetX;
+}
+
+void DrawString(Font font, String16 text, Vector2 position, float fontSize, float spacing, Color tint) {
+    if (font.texture.id == 0) font = GetFontDefault(); // Security check in case of not valid font
+
+    float textOffsetX = 0.0f; // Offset X to next character to draw
+
+    float scaleFactor = fontSize / font.baseSize; // Character quad scaling factor
+
+    for (int i = 0; i < text.len; i += 1) {
+        // Get next codepoint from byte string and glyph index in font
+        int codepoint = text[i];
+        int index     = GetGlyphIndex(font, codepoint);
+
+        if ((codepoint != '\n') && (codepoint != ' ') && (codepoint != '\t')) {
+            DrawTextCodepoint(font, codepoint, {position.x + textOffsetX, position.y}, fontSize, tint);
+        }
+
+        if (font.glyphs[index].advanceX == 0) textOffsetX += ((float)font.recs[index].width * scaleFactor + spacing);
+        else textOffsetX += ((float)font.glyphs[index].advanceX * scaleFactor + spacing);
+    }
+}
+
+Vector2 MeasureString(Font font, String16 text, float fontSize, float spacing) {
+    Vector2 textSize = {0};
+    if ((font.texture.id == 0) || (text.data == NULL)) return textSize; // Security check
+
+    int size            = (int)text.len; // Get size in bytes of text
+    int tempByteCounter = 0;             // Used to count longer text line num chars
+    int byteCounter     = 0;
+
+    float textWidth     = 0.0f;
+    float tempTextWidth = 0.0f; // Used to count longer text line width
+
+    float textHeight  = fontSize;
+    float scaleFactor = fontSize / (float)font.baseSize;
+
+    for (int i = 0; i < size; i += 1) {
+        int index = GetGlyphIndex(font, text[i]);
+
+        if (font.glyphs[index].advanceX != 0) textWidth += font.glyphs[index].advanceX;
+        else textWidth += (font.recs[index].width + font.glyphs[index].offsetX);
+    }
+
+    if (tempTextWidth < textWidth) tempTextWidth = textWidth;
+
+    textSize.x = tempTextWidth * scaleFactor + (float)((tempByteCounter - 1) * spacing);
+    textSize.y = textHeight;
+
+    return textSize;
+}

src/text_editor/text_editor.cpp

@@ -2,6 +2,8 @@
 #include "../basic/basic.h"
 #include "new_basic.cpp"
 #include "string16.cpp"
+#include <math.h>
+#include "math.cpp"
 
 #include "buffer.h"
 #include "buffer_helpers.cpp"
@@ -10,20 +12,63 @@
 #include "buffer_history.cpp"
 
 #include "raylib.h"
+#include "raylib_utils.cpp"
+#include "view.cpp"
+#include "view_draw.cpp"
 
 int main(void) {
     InitScratch();
     Test();
     TestBuffer();
     TestBufferMultiCursor();
-    return 0;
 
+    Arena Perm = {};
+    InitArena(&Perm);
+
+    SetWindowState(FLAG_WINDOW_RESIZABLE | FLAG_WINDOW_HIGHDPI | FLAG_MSAA_4X_HINT);
     InitWindow(1280, 720, "hello :)");
+    SetExitKey(KEY_F5);
     SetTargetFPS(60);
+    {
+        uint32_t data              = 0xffdddddd;
+        Image    window_icon_image = {(void *)&data, 1, 1, 1, PIXELFORMAT_UNCOMPRESSED_R8G8B8A8};
+        SetWindowIcon(window_icon_image);
+    }
+
+    View view = {};
+    {
+        float font_size    = 32;
+        float font_spacing = 1;
+        float line_spacing = font_size;
+        Font  font         = LoadFontEx("c:\\Windows\\Fonts\\consola.ttf", (int)font_size, NULL, 250);
+
+        view.font         = font;
+        view.font_size    = font_size;
+        view.font_spacing = font_spacing;
+        view.line_spacing = line_spacing;
+        view.char_spacing = GetCharSpacing(font, font_size, font_spacing);
+        Add(&view.cursors, {0, 0});
+        view.buffer = CreateBuffer(Perm);
+        {
+            Scratch scratch;
+            for (int i = 0; i < 150; i += 1) {
+                String   s   = Format(scratch, "line1: %d line2: %d line3: %d line4: %d line5: %d line6: %d line1: %d line2: %d line3: %d line4: %d line5: %d line6: %d\n", i, i, i, i, i, i, i, i, i, i, i, i);
+                String16 s16 = ToString16(scratch, s);
+                ReplaceText(view.buffer, GetEndAsRange(*view.buffer), s16);
+            }
+        }
+    }
+
     while (!WindowShouldClose()) {
+        view.rect = GetScreenRect();
+        HandleKeybindings(&view);
+
         BeginDrawing();
         ClearBackground(RAYWHITE);
-        DrawText("Congrats! You created your first window!", 190, 200, 20, LIGHTGRAY);
+        {
+            DrawVisibleCells(view);
+            For(view.cursors) DrawCursor(view, it);
+        }
         EndDrawing();
     }
     CloseWindow();

src/text_editor/view.cpp

@@ -0,0 +1,50 @@
+struct View {
+    Font  font;
+    float font_size;
+    float font_spacing;
+    float line_spacing;
+    float char_spacing;
+
+    Vec2          scroll;
+    Buffer       *buffer;
+    Array<Cursor> cursors;
+    Rect2         rect;
+};
+
+Int MovePos(Buffer &buffer, Int pos, XY offset) {
+    XY  xy     = PosToXY(buffer, pos);
+    Int result = XYToPos(buffer, {xy.col + offset.col, xy.line + offset.line});
+    return result;
+}
+
+void HandleKeybindings(View *_view) {
+    View   &view = *_view;
+    Buffer &buf  = *view.buffer;
+
+    if (IsKeyDown(KEY_F1)) {
+        view.scroll.x -= GetMouseWheelMove() * 48;
+    } else {
+        view.scroll.y -= GetMouseWheelMove() * 48;
+    }
+
+    if (IsKeyPressed(KEY_DOWN) || IsKeyPressedRepeat(KEY_DOWN)) {
+        For(view.cursors) {
+            if (IsKeyDown(KEY_LEFT_SHIFT)) {
+                Int front     = GetFront(it);
+                Int new_front = MovePos(buf, front, {0, 1});
+                it            = ChangeFront(it, new_front);
+            } else {
+                it.range.max = it.range.min = MovePos(buf, it.range.max, {0, 1});
+            }
+        }
+    }
+
+    // Clip scroll
+    {
+        Int last_line = LastLine(view.buffer[0]);
+        view.scroll.y = Clamp(view.scroll.y, 0.f, Max(0.f, (last_line - 1) * view.line_spacing));
+
+        Int line_chars = GetCharCountOfLongestLine(view.buffer[0]);
+        view.scroll.x  = Clamp(view.scroll.x, 0.f, Max(0.f, (line_chars - 2) * view.char_spacing));
+    }
+}

src/text_editor/view_draw.cpp

@@ -0,0 +1,70 @@
+
+Rect2I GetVisibleCells(const View &view) {
+    Vec2  size = GetSize(view.rect);
+    float _cx  = size.x / view.char_spacing;
+    float _cy  = size.y / view.line_spacing;
+    int   cx   = (int)ceilf(_cx) + 1;
+    int   cy   = (int)ceilf(_cy) + 1;
+
+    Vec2   pos    = {SafeDivide(view.scroll.x, view.char_spacing), SafeDivide(view.scroll.y, view.line_spacing)};
+    int    x      = (int)floorf(pos.x);
+    int    y      = (int)floorf(pos.y);
+    Rect2I result = {x, y, x + cx, y + cy};
+    return result;
+}
+
+void DrawVisibleCells(const View &view) {
+    Rect2I visible = GetVisibleCells(view);
+    for (Int line_index = visible.min.y; line_index < visible.max.y && line_index >= 0 && line_index < view.buffer->line_starts.len; line_index += 1) {
+        Range    line_range  = GetLine(*view.buffer, line_index);
+        String16 line_string = GetString(*view.buffer, line_range);
+        line_string          = Skip(line_string, visible.min.x);
+        line_string          = GetPrefix(line_string, visible.max.x - visible.min.x);
+
+        Vec2 pos = {visible.min.x * view.char_spacing, line_index * view.line_spacing};
+        pos -= view.scroll;
+        DrawString(view.font, line_string, pos, view.font_size, view.font_spacing, BLACK);
+    }
+}
+
+void DrawCursor(const View &view, XY xy, float size, Color color) {
+    Rect2 _rect = Rect2FromSize({(float)xy.col * view.char_spacing, (float)xy.line * view.line_spacing}, {view.char_spacing, view.line_spacing});
+    Rect2 rect  = CutLeft(&_rect, size);
+    rect -= view.scroll;
+    DrawRectangleRec(ToRectangle(rect), color);
+}
+
+void DrawCursor(const View &view, Cursor it) {
+    Buffer &buf   = *view.buffer;
+    Int     front = GetFront(it);
+    XY      fxy   = PosToXY(buf, front);
+    DrawCursor(view, fxy, 2, RED);
+
+    Int back = GetBack(it);
+    XY  bxy  = PosToXY(buf, back);
+    DrawCursor(view, bxy, 1, GREEN);
+
+    // Draw selection
+    {
+        XY min = PosToXY(buf, it.range.min);
+        XY max = PosToXY(buf, it.range.max);
+
+        Rect2I vlines = GetVisibleCells(view);
+        vlines.min.y  = Clamp(vlines.min.y, min.line, max.line);
+        vlines.max.y  = Clamp(vlines.max.y, min.line, max.line);
+
+        for (Int line = vlines.min.y; line < vlines.max.y; line += 1) {
+            Range range = GetLine(buf, line);
+            range -= range.min;
+            range.min = Clamp(range.min, vlines.min.x, vlines.max.x);
+            range.max = Clamp(range.max, vlines.min.x, vlines.max.x);
+
+            for (Int col = range.min; col < range.max; col += 1) {
+                Vec2 pos = {col * view.char_spacing, line * view.line_spacing};
+                pos -= view.scroll;
+                Rectangle rectangle = {pos.x, pos.y, view.char_spacing, view.line_spacing};
+                DrawRectangleRec(rectangle, {0, 50, 150, 20});
+            }
+        }
+    }
+}