4coder/4ed_buffer.cpp

1058 lines
33 KiB
C++

/*
* Mr. 4th Dimention - Allen Webster
*
* 06.01.2017
*
* The 4coder base buffer data structure.
*
*/
// TOP
//
// Buffer low level operations
//
internal void
write_cursor_with_index(Cursor_With_Index *positions, i32 *count, i64 pos){
positions[*count].index = *count;
positions[*count].pos = pos;
++(*count);
}
// TODO(allen): Rewrite this without being a dumbass.
// TODO(allen): Rewrite this without being a dumbass.
// TODO(allen): Rewrite this without being a dumbass.
#define CursorSwap__(a,b) { Cursor_With_Index t = a; a = b; b = t; }
// TODO(allen): Rewrite this without being a dumbass.
internal void
buffer_quick_sort_cursors(Cursor_With_Index *positions, i32 start, i32 pivot){
i32 mid = start;
i64 pivot_pos = positions[pivot].pos;
for (i32 i = mid; i < pivot; ++i){
if (positions[i].pos < pivot_pos){
CursorSwap__(positions[mid], positions[i]);
++mid;
}
}
CursorSwap__(positions[mid], positions[pivot]);
if (start < mid - 1){
buffer_quick_sort_cursors(positions, start, mid - 1);
}
if (mid + 1 < pivot){
buffer_quick_sort_cursors(positions, mid + 1, pivot);
}
}
// TODO(allen): Rewrite this without being a dumbass.
internal void
buffer_quick_unsort_cursors(Cursor_With_Index *positions, i32 start, i32 pivot){
i32 mid = start;
i32 pivot_index = positions[pivot].index;
for (i32 i = mid; i < pivot; ++i){
if (positions[i].index < pivot_index){
CursorSwap__(positions[mid], positions[i]);
++mid;
}
}
CursorSwap__(positions[mid], positions[pivot]);
if (start < mid - 1) buffer_quick_unsort_cursors(positions, start, mid - 1);
if (mid + 1 < pivot) buffer_quick_unsort_cursors(positions, mid + 1, pivot);
}
#undef CursorSwap__
internal void
buffer_sort_cursors(Cursor_With_Index *positions, i32 count){
if (count > 0){
buffer_quick_sort_cursors(positions, 0, count - 1);
}
}
internal void
buffer_unsort_cursors(Cursor_With_Index *positions, i32 count){
if (count > 0){
buffer_quick_unsort_cursors(positions, 0, count - 1);
}
}
internal void
buffer_update_cursors(Cursor_With_Index *sorted_positions, i32 count,
i64 start, i64 end, i64 len, b32 lean_right){
i64 shift_amount = replace_range_shift(start, end, len);
Cursor_With_Index *position = sorted_positions + count - 1;
if (lean_right){
for (; position >= sorted_positions && position->pos > end; --position){
position->pos += shift_amount;
}
for (; position >= sorted_positions && position->pos >= start; --position){
position->pos = start + len;
}
}
else{
for (; position >= sorted_positions && position->pos > end; --position){
position->pos += shift_amount;
}
for (; position >= sorted_positions && position->pos >= start; --position){
position->pos = start;
}
}
}
//////////////////////////////////////
internal i32
eol_convert_in(char *dest, char *src, i32 size){
i32 i = 0;
i32 j = 0;
i32 k = 0;
for (; j < size && src[j] != '\r'; ++j);
block_copy(dest, src, j);
if (j < size){
k = 1;
++j;
for (i = j; i < size; ++i){
if (src[i] == '\r'){
block_copy(dest + j - k, src + j, i - j);
++k;
j = i+1;
}
}
block_copy(dest + j - k, src + j, i - j);
j = i - k;
}
return(j);
}
internal i32
eol_in_place_convert_in(char *data, i32 size){
i32 i = 0;
i32 j = 0;
i32 k = 0;
for (; j < size && data[j] != '\r'; ++j);
if (j < size){
k = 1;
++j;
for (i = j; i < size; ++i){
if (data[i] == '\r'){
block_copy(data + j - k, data + j, i - j);
++k;
j = i+1;
}
}
block_copy(data + j - k, data + j, i - j);
j = i - k;
}
return(j);
}
// TODO(allen): iterative memory check?
internal b32
eol_convert_out(char *dest, i64 max, char *src, i64 size, i64 *size_out){
i64 j = 0;
for (i64 i = 0; i < size; ++i, ++j){
if (src[i] == '\n'){
dest[j] = '\r';
++j;
dest[j] = '\n';
}
else{
dest[j] = src[i];
}
}
*size_out = j;
return(true);
}
// TODO(allen): iterative memory check?
internal i32
eol_in_place_convert_out(char *data, i32 size, i32 max, i32 *size_out){
i32 result = 1;
i32 i = 0;
for (; i < size; ++i){
if (data[i] == '\n'){
block_copy(data + i + 1, data + i, size - i);
data[i] = '\r';
++i;
++size;
}
}
*size_out = size;
return(result);
}
//////////////////////////////////////
internal b32
buffer_good(Gap_Buffer *buffer){
return(buffer->data != 0);
}
internal i64
buffer_size(Gap_Buffer *buffer){
return(buffer->size1 + buffer->size2);
}
internal i64
buffer_line_count(Gap_Buffer *buffer){
return(buffer->line_start_count - 1);
}
internal void
buffer_init(Gap_Buffer *buffer, u8 *data, umem size, Base_Allocator *allocator){
block_zero_struct(buffer);
buffer->allocator = allocator;
umem capacity = round_up_umem(size*2, KB(4));
Data memory = base_allocate(allocator, capacity);
buffer->data = (u8*)memory.data;
buffer->size1 = size/2;
buffer->gap_size = capacity - size;
buffer->size2 = size - buffer->size1;
buffer->max = capacity;
block_copy(buffer->data, data, buffer->size1);
block_copy(buffer->data + buffer->size1 + buffer->gap_size, data + buffer->size1, buffer->size2);
}
internal b32
buffer_replace_range(Gap_Buffer *buffer, Range_i64 range, String_Const_u8 text, i64 shift_amount){
i64 size = buffer_size(buffer);
Assert(0 <= range.start);
Assert(range.start <= range.end);
Assert(range.end <= size);
if (shift_amount + size > buffer->max){
i64 new_max = round_up_i64(2*(shift_amount + size), KB(4));
i64 new_gap_size = new_max - size;
Data new_memory_data = base_allocate(buffer->allocator, new_max);
u8 *new_memory = (u8*)new_memory_data.data;
block_copy(new_memory, buffer->data, buffer->size1);
block_copy(new_memory + buffer->size1 + new_gap_size, buffer->data + buffer->size1 + buffer->gap_size,
buffer->size2);
base_free(buffer->allocator, buffer->data);
buffer->data = new_memory;
buffer->gap_size = new_gap_size;
buffer->max = new_max;
}
Assert(shift_amount + size <= buffer->max);
b32 result = false;
if (range.end < buffer->size1){
i64 move_size = buffer->size1 - range.end;
block_copy(buffer->data + buffer->size1 + buffer->gap_size - move_size,
buffer->data + range.end,
move_size);
buffer->size1 -= move_size;
buffer->size2 += move_size;
}
if (range.start > buffer->size1){
i64 move_size = range.start - buffer->size1;
block_copy(buffer->data + buffer->size1,
buffer->data + buffer->size1 + buffer->gap_size,
move_size);
buffer->size1 += move_size;
buffer->size2 -= move_size;
}
block_copy(buffer->data + range.start, text.str, text.size);
buffer->size2 = size - range.end;
buffer->size1 = range.start + text.size;
buffer->gap_size -= shift_amount;
Assert(buffer->size1 + buffer->size2 == size + shift_amount);
Assert(buffer->size1 + buffer->gap_size + buffer->size2 == buffer->max);
return(result);
}
////////////////////////////////
internal List_String_Const_u8
buffer_get_chunks(Arena *arena, Gap_Buffer *buffer){
List_String_Const_u8 list = {};
if (buffer->size1 > 0){
string_list_push(arena, &list, SCu8(buffer->data, buffer->size1));
}
if (buffer->size2 > 0){
umem gap_2_pos = buffer->size1 + buffer->gap_size;
string_list_push(arena, &list, SCu8(buffer->data + gap_2_pos, buffer->size2));
}
return(list);
}
internal void
buffer_chunks_clamp(List_String_Const_u8 *chunks, Interval_i64 range){
i64 p = 0;
List_String_Const_u8 list = {};
for (Node_String_Const_u8 *node = chunks->first, *next = 0;
node != 0;
node = next){
next = node->next;
Interval_i64 node_range = Ii64(p, p + node->string.size);
if (range_overlap(range, node_range)){
i64 first = max(node_range.first, range.first) - node_range.first;
i64 one_past_last = min(node_range.one_past_last, range.one_past_last) - node_range.first;
String_Const_u8 s = string_prefix(node->string, one_past_last);
node->string = string_skip(s, first);
sll_queue_push(list.first, list.last, node);
list.total_size += node->string.size;
list.node_count += 1;
}
p = node_range.one_past_last;
}
*chunks = list;
}
internal String_Const_u8
buffer_stringify(Arena *arena, Gap_Buffer *buffer, Interval_i64 range){
List_String_Const_u8 list = buffer_get_chunks(arena, buffer);
buffer_chunks_clamp(&list, range);
return(string_list_flatten(arena, list, StringFill_NullTerminate));
}
internal String_Const_u8
buffer_eol_convert_out(Arena *arena, Gap_Buffer *buffer, Interval_i64 range){
List_String_Const_u8 list = buffer_get_chunks(arena, buffer);
buffer_chunks_clamp(&list, range);
umem cap = list.total_size*2;
u8 *memory = push_array(arena, u8, cap);
u8 *memory_opl = memory + cap;
u8 *ptr = memory;
for (Node_String_Const_u8 *node = list.first;
node != 0;
node = node->next){
u8 *byte = node->string.str;
u8 *byte_opl = byte + node->string.size;
for (;byte < byte_opl; byte += 1){
if (*byte == '\n'){
*ptr = '\r';
ptr += 1;
*ptr = '\n';
ptr += 1;
}
else{
*ptr = *byte;
ptr += 1;
}
}
}
linalloc_pop(arena, (memory_opl - ptr));
push_align(arena, 8);
return(SCu8(memory, ptr));
}
internal i64
buffer_count_newlines(Arena *scratch, Gap_Buffer *buffer, i64 start, i64 end){
Temp_Memory temp = begin_temp(scratch);
List_String_Const_u8 list = buffer_get_chunks(scratch, buffer);
buffer_chunks_clamp(&list, Ii64(start, end));
i64 count = 0;
for (Node_String_Const_u8 *node = list.first;
node != 0;
node = node->next){
u8 *byte = node->string.str;
u8 *byte_opl = byte + node->string.size;
for (;byte < byte_opl; byte += 1){
if (*byte == '\n'){
count += 1;
}
}
}
end_temp(temp);
return(count);
}
internal void
buffer_starts__ensure_max_size(Gap_Buffer *buffer, i64 max_size){
if (max_size > buffer->line_start_max){
i64 new_max = round_up_i64(max_size*2, KB(1));
Data memory = base_allocate(buffer->allocator, sizeof(*buffer->line_starts)*new_max);
i64 *new_line_starts = (i64*)memory.data;
block_copy_dynamic_array(new_line_starts, buffer->line_starts, buffer->line_start_count);
buffer->line_start_max = new_max;
base_free(buffer->allocator, buffer->line_starts);
buffer->line_starts = new_line_starts;
}
}
internal void
buffer_measure_starts__write(Gap_Buffer *buffer, i64 pos){
buffer_starts__ensure_max_size(buffer, buffer->line_start_count + 1);
buffer->line_starts[buffer->line_start_count] = pos;
buffer->line_start_count += 1;
}
internal void
buffer_measure_starts(Arena *scratch, Gap_Buffer *buffer){
Temp_Memory temp = begin_temp(scratch);
List_String_Const_u8 list = buffer_get_chunks(scratch, buffer);
buffer->line_start_count = 0;
buffer_measure_starts__write(buffer, 0);
i64 index = 0;
for (Node_String_Const_u8 *node = list.first;
node != 0;
node = node->next){
u8 *byte = node->string.str;
u8 *byte_opl = byte + node->string.size;
for (;byte < byte_opl; byte += 1){
index += 1;
if (*byte == '\n'){
buffer_measure_starts__write(buffer, index);
}
}
}
buffer_measure_starts__write(buffer, buffer_size(buffer));
end_temp(temp);
}
internal void
buffer_remeasure_starts(Arena *scratch, Gap_Buffer *buffer, Interval_i64 old_line_indexes, i64 line_shift, i64 text_shift){
Temp_Memory temp = begin_temp(scratch);
buffer_starts__ensure_max_size(buffer, buffer->line_start_count + line_shift);
i64 new_line_indexes_opl = old_line_indexes.one_past_last + line_shift;
i64 old_line_start_count = buffer->line_start_count;
i64 *line_start_ptr = buffer->line_starts + old_line_indexes.one_past_last;
for (i64 i = old_line_indexes.one_past_last; i < old_line_start_count; i += 1, line_start_ptr += 1){
*line_start_ptr += text_shift;
}
block_copy_dynamic_array(buffer->line_starts + new_line_indexes_opl,
buffer->line_starts + old_line_indexes.one_past_last,
buffer->line_start_count - old_line_indexes.one_past_last);
i64 first_pos = buffer->line_starts[old_line_indexes.first];
i64 write_counter = old_line_indexes.first + 1;
i64 pos = first_pos;
List_String_Const_u8 list = buffer_get_chunks(scratch, buffer);
buffer_chunks_clamp(&list, Ii64(first_pos, buffer_size(buffer)));
for (Node_String_Const_u8 *node = list.first;
node != 0;
node = node->next){
u8 *byte = node->string.str;
u8 *byte_opl = byte + node->string.size;
for (;byte < byte_opl; byte += 1){
pos += 1;
if (*byte == '\n'){
buffer->line_starts[write_counter] = pos;
write_counter += 1;
if (write_counter == new_line_indexes_opl){
goto double_break;
}
}
}
}
double_break:;
buffer->line_start_count += line_shift;
end_temp(temp);
}
internal i64
buffer_get_line_index(Gap_Buffer *buffer, i64 pos){
i64 i = 0;
if (buffer->line_start_count > 2){
i64 start = 0;
i64 one_past_last = buffer->line_start_count - 1;
i64 *array = buffer->line_starts;
pos = clamp_bot(0, pos);
for (;;){
i = (start + one_past_last) >> 1;
if (array[i] < pos){
start = i;
}
else if (array[i] > pos){
one_past_last = i;
}
else{
break;
}
if (start + 1 >= one_past_last){
i = start;
break;
}
}
}
return(i);
}
internal Interval_i64
buffer_get_pos_range_from_line_number(Gap_Buffer *buffer, i64 line_number){
Interval_i64 result = {};
if (1 <= line_number && line_number < buffer->line_start_count){
result.first = buffer->line_starts[line_number - 1];
result.one_past_last = buffer->line_starts[line_number];
}
return(result);
}
internal i64
buffer_get_first_pos_from_line_number(Gap_Buffer *buffer, i64 line_number){
i64 result = {};
if (line_number < 1){
result = 0;
}
else if (line_number >= buffer->line_start_count){
result = buffer_size(buffer);
}
else{
result = buffer->line_starts[line_number - 1];
}
return(result);
}
internal i64
buffer_get_last_pos_from_line_number(Gap_Buffer *buffer, i64 line_number){
i64 result = {};
if (line_number < 1){
result = 0;
}
else if (line_number >= buffer->line_start_count - 1){
result = buffer_size(buffer);
}
else{
result = buffer->line_starts[line_number] - 1;
}
return(result);
}
internal Buffer_Cursor
buffer_cursor_from_pos(Gap_Buffer *buffer, i64 pos){
i64 size = buffer_size(buffer);
pos = clamp(0, pos, size);
i64 line_index = buffer_get_line_index(buffer, pos);
Buffer_Cursor result = {};
result.pos = pos;
result.line = line_index + 1;
result.col = pos - buffer->line_starts[line_index] + 1;
return(result);
}
internal Buffer_Cursor
buffer_cursor_from_line_col(Gap_Buffer *buffer, i64 line, i64 col){
i64 size = buffer_size(buffer);
i64 line_index = line - 1;
i64 line_count = buffer_line_count(buffer);
line_index = clamp(0, line_index, line_count - 1);
i64 this_start = buffer->line_starts[line_index];
i64 max_col = (buffer->line_starts[line_index + 1] - this_start);
if (line_index + 1 == line_count){
max_col += 1;
}
max_col = clamp_bot(1, max_col);
if (col < 0){
if (-col > max_col){
col = 1;
}
else{
col = max_col + col + 1;
}
}
else if (col == 0){
col = 1;
}
else{
col = clamp_top(col, max_col);
}
Assert(col > 0);
i64 adjusted_pos = col - 1;
i64 pos = this_start + adjusted_pos;
Buffer_Cursor result = {};
result.pos = pos;
result.line = line_index + 1;
result.col = col;
return(result);
}
internal String_Const_u8
buffer_invert_edit_shift(Arena *arena, Gap_Buffer *buffer, Edit edit, Edit *inv, i64 shift_amount){
String_Const_u8 string = buffer_stringify(arena, buffer, edit.range);
inv->text = string;
inv->range = Ii64(edit.range.start + shift_amount, edit.range.start + edit.text.size + shift_amount);
return(string);
}
internal b32
buffer_invert_batch(Arena *arena, Gap_Buffer *buffer, Edit *edits, Edit *inverse, i64 count){
b32 result = false;
i64 pos = 0;
i64 shift_amount = 0;
Edit *edit = edits;
Edit *inv_edit = inverse;
for (i64 i = 0; i < count; i += 1, edit += 1, inv_edit += 1){
String_Const_u8 inv_str = buffer_invert_edit_shift(arena, buffer, *edit, inv_edit, shift_amount);
shift_amount += replace_range_shift(edit->range, edit->text.size);
pos += inv_str.size;
}
return(result);
}
internal Buffer_Chunk_Position
buffer_get_chunk_position(String_Const_u8_Array chunks, i64 buffer_size, i64 real_pos){
Buffer_Chunk_Position pos = {};
pos.real_pos = real_pos;
pos.chunk_pos = real_pos;
if (pos.real_pos != buffer_size){
for (;(imem)(chunks.vals[pos.chunk_index].size) <= pos.chunk_pos;){
Assert(pos.chunk_index < chunks.count);
pos.chunk_pos -= (i32)chunks.vals[pos.chunk_index].size;
pos.chunk_index += 1;
}
}
else{
pos.chunk_index = chunks.count - 1;
pos.chunk_pos = (i32)chunks.vals[pos.chunk_index].size;
}
return(pos);
}
internal i32
buffer_chunk_position_iterate(String_Const_u8_Array chunks, Buffer_Chunk_Position *pos, Scan_Direction direction){
i32 past_end = 0;
pos->real_pos += direction;
pos->chunk_pos += direction;
if (pos->chunk_pos < 0){
if (pos->chunk_index == 0){
past_end = -1;
}
else{
pos->chunk_index -= 1;
pos->chunk_pos = (i32)chunks.vals[pos->chunk_index].size - 1;
}
}
else if (pos->chunk_pos >= (imem)(chunks.vals[pos->chunk_index].size)){
pos->chunk_index += 1;
if (pos->chunk_index == chunks.count){
past_end = 1;
}
else{
pos->chunk_pos = 0;
}
}
return(past_end);
}
////////////////////////////////
internal void
buffer_layout__write(Arena *arena, Buffer_Layout_Item_List *list, i64 index, u32 codepoint,
Buffer_Layout_Flag flags, Rect_f32 rect){
Temp_Memory restore_point = begin_temp(arena);
Buffer_Layout_Item *item = push_array(arena, Buffer_Layout_Item, 1);
Buffer_Layout_Item_Block *block = list->first;
if (block != 0){
if (block->items + block->count == item){
block->count += 1;
}
else{
block = 0;
}
}
if (block == 0){
end_temp(restore_point);
block = push_array(arena, Buffer_Layout_Item_Block, 1);
item = push_array(arena, Buffer_Layout_Item, 1);
sll_queue_push(list->first, list->last, block);
list->node_count += 1;
block->items = item;
block->count = 1;
}
list->total_count += 1;
if (index > list->index_range.max){
block->character_count += 1;
list->character_count += 1;
list->index_range.max = index;
}
item->index = index;
item->codepoint = codepoint;
item->flags = flags;
item->rect = rect;
list->height = max(list->height, rect.y1);
}
internal Buffer_Layout_Item_List
buffer_layout(Thread_Context *tctx, Arena *arena, Gap_Buffer *buffer, Interval_i64 range, Face *face, f32 width){
Scratch_Block scratch(tctx);
Buffer_Layout_Item_List list = {};
list.index_range.first = range.first;
list.index_range.one_past_last = range.first - 1;
List_String_Const_u8 chunks = buffer_get_chunks(scratch, buffer);
buffer_chunks_clamp(&chunks, range);
f32 line_height = face->line_height;
f32 text_height = face->text_height;
f32 line_to_text_shift = text_height - line_height;
f32 space_advance = face->space_advance;
if (chunks.node_count == 0){
f32 next_x = space_advance;
buffer_layout__write(arena, &list, range.first, ' ', 0,
Rf32(V2(0.f, 0.f), V2f32(next_x, text_height)));
}
else{
Vec2_f32 p = {};
f32 line_y = line_height;
f32 text_y = text_height;
String_Const_u8 text = {};
if (chunks.node_count == 1){
text = chunks.first->string;
}
else{
text = string_list_flatten(scratch, chunks);
}
i64 index = range.first;
b32 first_of_the_line = true;
b32 consuming_newline_characters = false;
i64 newline_character_index = -1;
b32 prev_did_emit_newline = false;
u8 *ptr = text.str;
u8 *end_ptr = ptr + text.size;
for (;ptr < end_ptr;){
Character_Consume_Result consume = utf8_consume(ptr, (umem)(end_ptr - ptr));
u32 render_codepoint = consume.codepoint;
b32 emit_newline = false;
switch (consume.codepoint){
case '\t':
{
render_codepoint = ' ';
}//fallthrough;
default:
{
f32 advance = font_get_glyph_advance(face, consume.codepoint);
f32 next_x = p.x + advance;
if (!first_of_the_line && next_x >= width){
p.y = line_y;
p.x = 0.f;
line_y += line_height;
text_y = line_y + line_to_text_shift;
next_x = p.x + advance;
}
buffer_layout__write(arena, &list, index, render_codepoint, 0,
Rf32(p, V2f32(next_x, text_y)));
p.x = next_x;
ptr += consume.inc;
index += consume.inc;
first_of_the_line = false;
}break;
case '\r':
{
if (!consuming_newline_characters){
consuming_newline_characters = true;
newline_character_index = index;
}
ptr += 1;
index += 1;
}break;
case '\n':
{
if (!consuming_newline_characters){
consuming_newline_characters = true;
newline_character_index = index;
}
emit_newline = true;
ptr += 1;
index += 1;
}break;
case max_u32:
{
f32 next_x = p.x + face->byte_advance;
if (!first_of_the_line && next_x >= width){
p.y = line_y;
p.x = 0.f;
line_y += line_height;
text_y = line_y + line_to_text_shift;
next_x = p.x + face->byte_advance;
}
u32 v = *ptr;
u32 lo = v&0xF;
u32 hi = (v >> 4)&0xF;
f32 advance = face->byte_sub_advances[0];
buffer_layout__write(arena, &list, index, '\\', 0,
Rf32(p, V2f32(p.x + advance, text_y)));
p.x += advance;
advance = face->byte_sub_advances[1];
buffer_layout__write(arena, &list, index, integer_symbols[lo], 0,
Rf32(p, V2f32(p.x + advance, text_y)));
p.x += advance;
face->byte_sub_advances[2];
buffer_layout__write(arena, &list, index, integer_symbols[hi], 0,
Rf32(p, V2f32(p.x + advance, text_y)));
p.x = next_x;
ptr += 1;
index += 1;
first_of_the_line = false;
}break;
}
prev_did_emit_newline = false;
if (emit_newline){
f32 next_x = p.x + space_advance;
buffer_layout__write(arena, &list, newline_character_index, ' ', 0,
Rf32(p, V2f32(next_x, text_y)));
p.y = line_y;
p.x = 0.f;
line_y += line_height;
text_y = line_y + line_to_text_shift;
first_of_the_line = true;
prev_did_emit_newline = true;
}
}
if (!prev_did_emit_newline){
f32 next_x = p.x + space_advance;
buffer_layout__write(arena, &list, index, ' ', 0, Rf32(p, V2f32(next_x, text_y)));
}
}
list.height -= line_to_text_shift;
return(list);
}
internal i64
buffer_layout_nearest_pos_to_xy(Buffer_Layout_Item_List list, Vec2_f32 p){
i64 closest_match = 0;
if (p.y < 0.f){
closest_match = list.index_range.min;
}
else if (p.y >= list.height){
closest_match = list.index_range.max + 1;
}
else{
if (0.f < p.x && p.x < max_f32){
f32 closest_x = -max_f32;
for (Buffer_Layout_Item_Block *block = list.first;
block != 0;
block = block->next){
i64 count = block->count;
Buffer_Layout_Item *item = block->items;
for (i32 i = 0; i < count; i += 1, item += 1){
// NOTE(allen): This only works if we build layouts in y-sorted order.
if (p.y < item->rect.y0){
goto double_break;
}
if (item->rect.y1 <= p.y){
continue;
}
f32 dist0 = p.x - item->rect.x0;
f32 dist1 = item->rect.x1 - p.x;
if (dist0 >= 0.f && dist1 > 0.f){
closest_match = item->index;
goto double_break;
}
// NOTE(allen): One of dist0 and dist1 are negative, but certainly not both.
// 1. Take the negative one.
// 2. If the negative distance is larger than closest_x, then this is closer.
f32 neg_dist = min(dist0, dist1);
if (closest_x < neg_dist){
closest_x = neg_dist;
closest_match = item->index;
}
}
}
double_break:;
}
else{
if (p.x == max_f32){
Buffer_Layout_Item *prev_item = 0;
for (Buffer_Layout_Item_Block *block = list.first;
block != 0;
block = block->next){
i64 count = block->count;
Buffer_Layout_Item *item = block->items;
for (i32 i = 0; i < count; i += 1, item += 1){
if (p.y < item->rect.y0){
goto double_break_2;
}
prev_item = item;
if (item->rect.y1 <= p.y){
continue;
}
}
}
double_break_2:;
if (prev_item != 0){
closest_match = prev_item->index;
}
else{
closest_match = list.index_range.max;
}
}
else{
Buffer_Layout_Item *closest_item = 0;
for (Buffer_Layout_Item_Block *block = list.first;
block != 0;
block = block->next){
i64 count = block->count;
Buffer_Layout_Item *item = block->items;
for (i32 i = 0; i < count; i += 1, item += 1){
// NOTE(allen): This only works if we build layouts in y-sorted order.
if (p.y < item->rect.y0){
goto double_break_3;
}
if (item->rect.y1 <= p.y){
continue;
}
closest_item = item;
goto double_break_3;
}
}
double_break_3:;
if (closest_item != 0){
closest_match = closest_item->index;
}
else{
closest_match = list.index_range.min;
}
}
}
}
return(closest_match);
}
internal i64
buffer_layout_get_pos_at_character(Buffer_Layout_Item_List list, i64 character){
i64 result = 0;
if (character <= 0){
result = list.index_range.min;
}
else if (character >= list.character_count){
result = list.index_range.max + 1;
}
else{
i64 counter = 0;
for (Buffer_Layout_Item_Block *node = list.first;
node != 0;
node = node->next){
i64 next_counter = counter + node->character_count;
if (character < next_counter){
i64 count = node->count;
i64 relative_character = character - counter;
i64 relative_character_counter = 0;
i64 prev_index = -1;
Buffer_Layout_Item *item = node->items;
for (i64 i = 0; i < count; i += 1, item += 1){
if (prev_index != item->index){
prev_index = item->index;
if (relative_character_counter == relative_character){
result = prev_index;
break;
}
relative_character_counter += 1;
}
}
break;
}
counter = next_counter;
}
}
return(result);
}
internal Buffer_Layout_Item*
buffer_layout_get_first_with_index(Buffer_Layout_Item_List list, i64 index){
Buffer_Layout_Item *result = 0;
Buffer_Layout_Item *prev = 0;
for (Buffer_Layout_Item_Block *block = list.first;
block != 0;
block = block->next){
i64 count = block->count;
Buffer_Layout_Item *item = block->items;
for (i32 i = 0; i < count; i += 1, item += 1){
if (item->index > index){
result = prev;
goto done;
}
if (item->index == index){
result = item;
goto done;
}
prev = item;
}
}
if (result == 0){
result = prev;
}
done:;
return(result);
}
internal Vec2_f32
buffer_layout_xy_center_of_pos(Buffer_Layout_Item_List list, i64 index){
Vec2_f32 result = {};
Buffer_Layout_Item *item = buffer_layout_get_first_with_index(list, index);
if (item != 0){
result = rect_center(item->rect);
}
return(result);
}
internal i64
buffer_layout_character_from_pos(Buffer_Layout_Item_List list, i64 index){
i64 result = 0;
i64 character_count = 0;
i64 prev_index = -1;
if (index <= list.index_range.first){
result = 0;
}
else if (index > list.index_range.one_past_last){
result = list.character_count - 1;
}
else{
for (Buffer_Layout_Item_Block *node = list.first;
node != 0;
node = node->next){
Buffer_Layout_Item *item = node->items;
i64 count = node->count;
for (i64 i = 0; i < count; i += 1, item += 1){
if (item->index == index){
result = character_count;
goto double_break;
}
if (item->index != prev_index){
prev_index = item->index;
character_count += 1;
}
}
}
}
double_break:;
return(result);
}
// BOTTOM