diff options
| -rw-r--r-- | buffer.c | 68 |
1 files changed, 51 insertions, 17 deletions
@@ -7,6 +7,7 @@ #include "util.c" #include "text.h" +// @TODO: make this bigger -- maybe 4000 (it's small now to test having a bunch of blocks) #define TEXT_BLOCK_MAX_SIZE 400 // Once two adjacent blocks are at most this big, combine them into // one bigger text block. @@ -20,9 +21,16 @@ typedef struct { char *contents; } TextBlock; +// a position in the buffer +typedef struct { + u32 block; + u32 idx; +} BufferPos; + typedef struct { double scroll_x, scroll_y; // number of characters scrolled in the x/y direction Font *font; + BufferPos cursor_pos; u8 tab_width; float x1, y1, x2, y2; u32 nblocks; // number of text blocks @@ -126,35 +134,46 @@ void buffer_free(TextBuffer *buffer) { free(blocks); } +// advance line and col according to the character c +// either can be NULL +static void buffer_update_line_col(TextBuffer *buffer, u64 *line, u64 *col, int c) { + if (line) { + if (c == '\n') ++*line; + } + if (col) { + switch (c) { + case '\n': + *col = 0; + break; + case '\r': break; + case '\t': + do + ++*col; + while (*col % buffer->tab_width); + break; + default: + ++*col; + break; + } + } +} + // returns the number of lines of text in the buffer into *lines (if not NULL), // and the number of columns of text, i.e. the length of the longest line, into *cols (if not NULL) static void buffer_text_dimensions(TextBuffer *buffer, u64 *lines, u64 *cols) { - u64 nlines = 1; + // @OPTIMIZE + u64 line = 1; u64 maxcol = 0; u64 col = 0; for (u32 i = 0; i < buffer->nblocks; ++i) { TextBlock *block = &buffer->blocks[i]; for (char *p = block->contents, *end = p + block->len; p != end; ++p) { - switch (*p) { - case '\n': - ++nlines; - col = 0; - break; - case '\r': break; - case '\t': - do - ++col; - while (col % buffer->tab_width); - break; - default: - ++col; - break; - } + buffer_update_line_col(buffer, &line, &col, *p); if (col > maxcol) maxcol = col; } } - if (lines) *lines = nlines; + if (lines) *lines = line; if (cols) *cols = maxcol; } @@ -197,6 +216,21 @@ void buffer_scroll(TextBuffer *buffer, double dx, double dy) { buffer_correct_scroll(buffer); } +// returns the line and column of the given buffer position. +// line/col can be NULL. +void buffer_pos_to_line_col(TextBuffer *buffer, BufferPos pos, u64 *line, u64 *col) { + // @TODO +} + +// returns the position of the character at the given position in the buffer. +// x/y can be NULL. +void buffer_pos_to_pixels(TextBuffer *buffer, BufferPos pos, float *x, float *y) { + u64 line, col; + buffer_pos_to_line_col(buffer, pos, &line, &col); + if (x) *x = ((double)col - buffer->scroll_x) * font_char_width(buffer->font); + if (y) *y = ((double)line - buffer->scroll_y) * font_char_height(buffer->font); +} + // Render the text buffer in the given rectangle // NOTE: also corrects scroll void buffer_render(TextBuffer *buffer, float x1, float y1, float x2, float y2) { |