wip

.gitignore

@@ -1,3 +1,5 @@
 edit
 *.ttf
 .build
+main
+test

edit.jai

@@ -1,57 +1,76 @@
+// Todos:
+// - move by word
+// - select text
+// - copy selected text
+// - cut selected text
+// - move line up
+// - move line down
+// - duplicate line
+// - refactor to make cursor_x be aligned with characters themselves
+
+
 FPS          :: 60;
 MS_PER_FRAME :: 1000 / FPS;
 
-buffer: string;
-lines: [..]String_Builder;
-line_height: int;
+State :: struct {
+    file_name: string;
+    
+    cursor_x: int;
+    cursor_y: int;
+    
+    window_width: int;
+    window_height: int;
+    
+    buffer: string;
+    lines: [..][..]u8;
+    line_height: int;
+    first_line: int;
 
-my_font: *Simp.Dynamic_Font;
+    my_font: *Simp.Dynamic_Font;
+    dt: int;
+}
 
-window_width  := 800;
-window_height := 600;
+White :: Vector4.{1, 1, 1, 1};
 
-first_line := 0;
+Special_Character_Lookup : [10]u8 : .[
+    xx #char ")",
+    xx #char "!",
+    xx #char "@",
+    xx #char "#",
+    xx #char "$",
+    xx #char "%",
+    xx #char "^",
+    xx #char "&",
+    xx #char "*",
+    xx #char "(",
+];
 
-main :: () {
-    args := get_command_line_arguments();
-    assert(args.count == 2, "The file name must be passed as a CLI argument");
+run_editor :: (file_name: string) {
+    state: State;
+    state.window_width  = 800;
+    state.window_height = 600;
+    state.file_name = file_name;
+    window := create_window(state.window_width, state.window_height, state.file_name);
 
-
-    window_name := ifx args.count == 1 then "edit" else args[1];
-    window := create_window(window_width, window_height, window_name);
-
-    my_init_fonts();
+    my_init_fonts(*state);
 
     Simp.set_render_target(window);
 
     should_quit := false;
     prev := get_time();
 
-    assert(read_file_lines(args[1]), "Must be able to read file!");
+    assert(read_file_lines(*state, state.file_name), "Must be able to read file!");
 
     while !should_quit {
         reset_temporary_storage();
 
         now := get_time();
-        dt := now - prev;
+        state.dt = now - prev;
         prev = now;
 
         Input.update_window_events();
 
-        for Input.get_window_resizes() {
-            Simp.update_window(it.window);
-            if it.window == window {
-                should_reinit := (it.width != window_width) || (it.height != window_height);
-
-                window_width  = it.width;
-                window_height = it.height;
-
-                if should_reinit {
-                    my_init_fonts();
-                }
-            }
-        }
-
+        handle_window_resizes(*state, window);
 
         for event : Input.events_this_frame {
             if event.type == .QUIT {
@@ -62,13 +81,41 @@ main :: () {
             if event.type == .KEYBOARD && event.key_pressed {
                 if event.key_code == {
                     case .ESCAPE; should_quit = true;
+
+                    case .BACKSPACE; handle_backspace(*state);
+                    case .ENTER;     handle_enter(*state);
+
+                    case .ARROW_UP;    #through;
+                    case .ARROW_DOWN;  #through;
+                    case .ARROW_LEFT;  #through;
+                    case .ARROW_RIGHT; handle_arrow(*state, event);
+                }
+
+                if #char "A" <= event.key_code && event.key_code <= #char "z" {
+                    key := event.key_code;
+                    if !event.shift_pressed {
+                        key += #char "a" - #char "A";
+                    }
+
+                    if event.ctrl_pressed {
+                        if event.key_code == {
+                            case #char "S"; #through;
+                            case #char "s"; handle_save(*state);
+                        }
+                    } else {
+                        insert_character_at_cursor(*state, cast(u8) key);
+                    }
+                } else if 33 <= event.key_code && event.key_code <= 126 {
+                    // NOTE: this doesn't quite work for some keys, like ` or []
+                    key := event.key_code;
+                    insert_character_at_cursor(*state, cast(u8) key);
                 }
             }
         }
 
         Simp.clear_render_target(.0, .0, .0, 1);
 
-        render_edit_buffer();
+        render_edit_buffer(state);
 
         Simp.swap_buffers(window);
 
@@ -79,39 +126,221 @@ main :: () {
     }
 }
 
-render_edit_buffer :: () {
-    num_lines_in_screen := window_height / line_height - 1;
-    viewable_lines := array_view(lines, first_line, num_lines_in_screen);
-    Simp.set_shader_for_text();
-    color :: Vector4.{1, 1, 1, 1};
-    for line_buffer: viewable_lines {
+render_edit_buffer :: (using state: State) {
+    visible_lines := get_visible_lines(state);
+    for line_buffer: visible_lines {
+        Simp.set_shader_for_text();
 
-        line := builder_to_line(*line_buffer);
+        line_str := array_view_to_string(line_buffer);
+
+        prefix: string;
+        suffix: string;
+
+        has_cursor_on_line := it_index == cursor_y;
+
+        if has_cursor_on_line {
+            prefix, suffix = string_to_line(line_str, cursor_x);
+        } else {
+            prefix, suffix = string_to_line(line_str);
+        }
+
+        prefix_width := Simp.prepare_text(my_font, prefix);
+        top_of_line := window_height - (it_index + 1) * line_height;
+
+        Left_Max :: 5;
+        Simp.draw_prepared_text(my_font, Left_Max, top_of_line, White);
+
+        if has_cursor_on_line {
+            Simp.set_shader_for_color();
+            start := ifx cursor_x == 0 then Left_Max else prefix_width + Left_Max;
+            Simp.immediate_quad(
+                cast(float) start,     cast(float) top_of_line + line_height,
+                cast(float) start + 1, cast(float) top_of_line,
+                White);
+
+            Simp.set_shader_for_text();
+            Simp.prepare_text(my_font, suffix);
+            Simp.draw_prepared_text(my_font, start, top_of_line, White);
+        }
 
-        Simp.prepare_text(my_font, line);
-        Simp.draw_prepared_text(my_font, 5, window_height - (it_index + 1) * line_height, color);
     }
 }
 
-builder_to_line :: (using builder: *String_Builder) -> string {
-    result_builder: String_Builder;
-    result_builder.allocator = temporary_allocator;
+insert_character_at_cursor :: (using state: *State, char: u8) {
+    line := *get_visible_lines(state)[cursor_y];
+    array_insert_at(line, char, cursor_x);
+    cursor_x += 1;
+}
 
-    builder_str := builder_to_string(builder, do_reset = false,, temp);
+handle_save :: (using state: *State) {
+    out_builder: String_Builder;
+    init_string_builder(*out_builder);
 
-    start := 0;
-    for c: builder_str {
-        if c == #char "\t" {
-            s := string.{data=builder_str.data + start, count=(it_index + 1) - start};
-            append(*result_builder, s);
-            start = it_index + 1;
+    for line: lines {
+        line_str := string.{count=line.count, data=line.data};
+        append(*out_builder, line_str);
+        if it_index != lines.count - 1 {
+            append(*out_builder, "\n");
         }
     }
 
-    s := string.{data=builder_str.data + start, count=builder_str.count - start};
-    append(*result_builder, s);
+    content := builder_to_string(*out_builder);
+    out_file_name := tprint("%.new", file_name);
+    write_entire_file(out_file_name, content);
+}
 
-    return builder_to_string(*result_builder,, temp);
+handle_window_resizes :: (using state: *State, window: Window_Type) {
+    for Input.get_window_resizes() {
+        Simp.update_window(it.window);
+        if it.window == window {
+            should_reinit := (it.width != window_width) || (it.height != window_height);
+
+            window_width  = it.width;
+            window_height = it.height;
+
+            if should_reinit {
+                my_init_fonts(state);
+            }
+        }
+    }
+}
+
+handle_enter :: (using state: *State) {
+    cursor_line_index := cursor_y + first_line;
+    current_line := *lines[cursor_line_index];
+
+    new_line := [..]u8.{};
+    array_add(*new_line, array_view(current_line.*, cursor_x));
+
+    array_insert_at(*lines, new_line, cursor_line_index + 1);
+    current_line.count = cursor_x;
+
+    handle_arrow(state, .ARROW_DOWN);
+    cursor_x = 0;
+}
+
+handle_backspace :: (using state: *State) {
+    if cursor_x == 0 && cursor_y == 0 && first_line == 0 {
+        return;
+    }
+
+    cursor_line_index := cursor_y + first_line;
+    current_line := *lines[cursor_line_index];
+    if cursor_x == 0 {
+        prev_line := *lines[cursor_line_index - 1];
+        prev_count := prev_line.count;
+        array_add(prev_line, current_line.*);
+        array_remove_at(*lines, cursor_line_index);
+        handle_arrow(state, .ARROW_UP);
+        cursor_x = prev_count;
+    } else {
+        array_remove_at(current_line, cursor_x - 1);
+        cursor_x -= 1;
+    }
+}
+
+handle_arrow :: (state: *State, key_code: Input.Key_Code) {
+    handle_arrow(state, .{key_code=key_code});
+}
+
+handle_arrow :: (using state: *State, using event: Input.Event) {
+    visible_lines := get_visible_lines(state);
+    if visible_lines.count == 0 return;
+
+    if key_code == {
+        case .ARROW_UP;    
+            if cursor_y == 0 && first_line == 0 return;
+
+            if cursor_y == 0 {
+                first_line -= 1;
+            } else {
+                cursor_y -= 1;
+            }
+        case .ARROW_DOWN;
+            if cursor_y == visible_lines.count - 1 {
+                first_line = min(first_line + 1, lines.count);
+	    } else if cursor_y + first_line + visible_lines.count >= lines.count {
+	    } else {
+                cursor_y += 1;
+            }
+
+        case .ARROW_LEFT;
+            if cursor_x == 0 && cursor_y != 0 {
+                prev_line := visible_lines[cursor_y - 1];
+                len := prev_line.count;
+                cursor_y = max(0, cursor_y - 1);
+                cursor_x = len;
+            } else if cursor_x != 0 && ctrl_pressed {
+            } else if cursor_x != 0 {
+                cursor_x -= 1;
+	    }
+        case .ARROW_RIGHT;
+            line := visible_lines[cursor_y];
+            len := line.count;
+            if cursor_x == len {
+                cursor_x = 0;
+                cursor_y += 1;
+            } else if ctrl_pressed {
+            } else {
+                cursor_x += 1;
+	    }
+    }
+}
+
+get_visible_lines :: (using state: State) -> [][..]u8 {
+    if line_height <= 1 || window_height == 0 return .[];
+    num_lines_in_screen := window_height / line_height - 1;
+    return array_view(lines, first_line, num_lines_in_screen);
+}
+
+string_to_line :: (str: string, cursor_char_index := -1) -> string, string {
+    prefix_builder: String_Builder;
+    prefix_builder.allocator = temporary_allocator;
+
+    suffix_builder: String_Builder;
+    suffix_builder.allocator = temporary_allocator;
+
+    init_string_builder(*prefix_builder);
+    init_string_builder(*suffix_builder);
+
+    start := 0;
+    char_index := 0;
+    cursor_index := 0;
+
+    current_builder := *prefix_builder;
+
+    while char_index < str.count {
+        defer char_index += 1;
+        c := str.data[char_index];
+
+        if c == #char "\t" {
+
+            // s := string.{data=str.data + start, count=(char_index + 1) - start};
+            // append(current_builder, s);
+            // append(current_builder, "    ");
+            // start = char_index + 1;
+            // cursor_index += 4;
+
+        } else {
+            cursor_index += 1;
+        }
+
+        if cursor_index == cursor_char_index {
+            s := string.{data=str.data + start, count=(char_index + 1) - start};
+            append(current_builder, s);
+            current_builder = *suffix_builder;
+            start = char_index + 1;
+        } 
+    }
+
+
+    s := string.{data=str.data + start, count=str.count - start};
+    append(current_builder, s);
+
+    prefix := builder_to_string(*prefix_builder,, temp);
+    suffix := builder_to_string(*suffix_builder,, temp);
+
+    return prefix, suffix;
 }
 
 get_time :: () -> s64 {
@@ -120,28 +349,27 @@ get_time :: () -> s64 {
     return val;
 }
 
-read_file_lines :: (file_path: string) -> bool {
+read_file_lines :: (using state: *State, file_path: string) -> bool {
     file_contents, ok := read_entire_file(file_path);
     if !ok return ok;
 
-    for lines reset(*it);
+    for lines free(*it);
     free(lines.data);
-    lines = [..]String_Builder.{};
+    lines = [..][..]u8.{};
 
     lines_temp := split(file_contents, "\n");
     defer free(lines_temp.data);
 
     for line: lines_temp {
-        builder: String_Builder;
-        init_string_builder(*builder);
-        append(*builder, line);
+        builder: [..]u8;
+        array_add(*builder, array_view(line));
         array_add(*lines, builder);
     }
 
     return ok;
 }
 
-my_init_fonts :: () {
+my_init_fonts :: (using state: *State) {
     line_height = 16;
     base_path := path_strip_filename(get_path_of_running_executable());
 
@@ -150,6 +378,26 @@ my_init_fonts :: () {
     assert(my_font != null);
 }
 
+array_add :: (xs: *[..]$T, to_append: []T) {
+    array_reserve(xs, xs.count + to_append.count);
+
+    memcpy(xs.data + xs.count, to_append.data, to_append.count * size_of(T));
+    xs.count += to_append.count;
+}
+
+array_view :: (s: string) -> []u8 {
+    return []u8.{count=s.count, data=s.data};
+}
+
+array_view_to_string :: (chars: []u8) -> string {
+    return string.{count=chars.count, data=chars.data};
+}
+
+array_remove_at :: (xs: *[..]$T, index: int) {
+    xs.count -= 1;
+    memcpy(xs.data + index, xs.data + index + 1, xs.count - index);
+}
+
 #import "Basic";
 #import "File";
 #import "Math";

main.jai

@@ -0,0 +1,10 @@
+main :: () {
+    args := get_command_line_arguments();
+    assert(args.count == 2, "The file name must be passed as a CLI argument");
+
+    file_name := args[1];
+    run_editor(file_name);
+}
+
+#load "edit.jai";
+#import "Basic";

test.jai

@@ -0,0 +1,73 @@
+main :: () {
+    print("\nBeginning tests...\n");
+    // test_handle_arrow_empty_lines();
+    // test_handle_arrow_one_line();
+    x := 1;
+    y := 2;
+    assert_test(x == y);
+}
+
+test_handle_arrow_empty_lines :: () {
+    state: State;
+    state.cursor_y = 0;
+    state.cursor_x = 0;
+
+    codes := Input.Key_Code.[.ARROW_DOWN, .ARROW_UP, .ARROW_LEFT, .ARROW_RIGHT];
+    for codes {
+	handle_arrow(*state, .{key_code=it});
+	assert(state.cursor_x == 0 && state.cursor_y == 0, "%: cursor_x % & cursor_y %", it, state.cursor_x, state.cursor_y);
+    }
+
+    print("test_handle_arrow_empty_lines completed successfully\n");
+}
+
+test_handle_arrow_one_line :: () {
+    state: State;
+    state.cursor_y = 0;
+    state.cursor_x = 0;
+    
+    line: [..]u8;
+    line_str := "foo bar";
+    
+    array_add(*line, .{data=line_str.data, count=line_str.count});
+    array_add(*state.lines, line);
+
+    codes := Input.Key_Code.[.ARROW_DOWN, .ARROW_UP, .ARROW_LEFT];
+    for codes {
+	handle_arrow(*state, .{key_code=it});
+	assert(state.cursor_x == 0 && state.cursor_y == 0);
+    }
+
+    handle_arrow(*state, .{key_code=.ARROW_RIGHT});
+    assert(state.cursor_x == 1 && state.cursor_y == 0);    
+
+    print("test_handle_arrow_one_line completed successfully\n");
+}
+
+assert_test :: (value: bool, $code := #caller_code) {
+    builder: String_Builder;
+    root, expressions := compiler_get_nodes(code);
+    loc := #location(code);
+
+    print_to_builder(*builder, "%:%: Test: ", loc.fully_pathed_filename, loc.line_number);
+    print_expression(*builder, root);
+    append(*builder, "\n");
+    `result := #insert code;
+    if !result {
+	for expressions {
+	    if it == root continue;
+	    print_expression(*builder, it);
+	    append(*builder, "\n");
+	}
+	append(*builder, "\n");
+	`expression := builder_to_string(*builder);
+	`print("%\n", expression);
+    } else {
+	`print("Passed!\n");
+    }
+}
+
+#import,file "edit.jai";
+#import "Basic";
+#import "Compiler";
+#import "Program_Print";