kerning

7 files changed, 29 insertions, 7 deletions

diff --git a/README.md b/README.md
index 13f454e..bcb85b8 100644
--- a/README.md
+++ b/README.md
@@ -318,7 +318,7 @@ Then, open windows\_installer\\ted\\ted.sln, and build.
 <tr><td>2.3.2</td> <td>Misc bugfixes</td> <td>2023 Jun 17</td></tr>
 <tr><td>2.3.3</td> <td>JS highlighting improvments, fix TODO highlighting for single-line comments</td> <td>2023 Jul 6</td></tr>
 <tr><td>2.3.4</td> <td>Unicode bugfix, `:copy-path`</td> <td>2023 Jul 14</td></tr>
-<tr><td>2.4</td> <td>Font overhaul — allow multiple fonts, and variable-width fonts.</td> <td>2023 Jul 18</td></tr>
+<tr><td>2.4</td> <td>Font overhaul — allow multiple fonts, and variable-width fonts.</td> <td>2023 Jul 19</td></tr>
 </table>
 
 ## License
diff --git a/buffer.c b/buffer.c
index 0dd397d..b98717d 100644
--- a/buffer.c
+++ b/buffer.c
@@ -3021,6 +3021,7 @@ void buffer_render(TextBuffer *buffer, Rect r) {
 			rgba_u32_to_floats(colors[line == cursor_line ? COLOR_CURSOR_LINE_NUMBER : COLOR_LINE_NUMBERS],
 				text_state.color);
 			text_state.x = x; text_state.y = y;
+			text_state_break_kerning(&text_state);
 			text_utf8_with_state(font, &text_state, str);
 			y += char_height;
 			if (y > y2) break;
@@ -3196,6 +3197,7 @@ void buffer_render(TextBuffer *buffer, Rect r) {
 		}
 
 		// next line
+		text_state_break_kerning(&text_state);
 		text_state.x = render_start_x;
 		if (text_state.y > text_state.max_y) {
 			buffer->last_line_on_screen = line_idx;
diff --git a/main.c b/main.c
index 2985f3c..0f9b0e7 100644
--- a/main.c
+++ b/main.c
@@ -1,6 +1,4 @@
 /*
-TODO:
-- kerning
 FUTURE FEATURES:
 - autodetect indentation (tabs vs spaces)
 - font setting & support for multiple fonts to cover more characters
diff --git a/node.c b/node.c
index 29f08b9..43e83fc 100644
--- a/node.c
+++ b/node.c
@@ -324,6 +324,7 @@ void node_frame(Ted *ted, Node *node, Rect r) {
 				rgba_u32_to_floats(colors[COLOR_TEXT], text_state.color);
 				text_state.x = tab_rect.pos.x;
 				text_state.y = tab_rect.pos.y;
+				text_state_break_kerning(&text_state);
 				text_utf8_with_state(font, &text_state, tab_title);
 
 				if (i == node->active_tab) {
diff --git a/text.c b/text.c
index 29d1831..70941de 100644
--- a/text.c
+++ b/text.c
@@ -66,7 +66,8 @@ const TextRenderState text_render_state_default = {
 	.min_x = -FLT_MAX, .max_x = +FLT_MAX,
 	.min_y = -FLT_MAX, .max_y = +FLT_MAX,
 	.color = {1, 0, 1, 1},
-	.x_largest = -FLT_MAX, .y_largest = -FLT_MAX
+	.x_largest = -FLT_MAX, .y_largest = -FLT_MAX,
+	.prev_char = 0,
 };
 
 static char text_err[200];
@@ -388,12 +389,18 @@ top:
 		goto ret;
 	}
 	
+	if (!font->force_monospace && state->prev_char && state->prev_char != '\n') {
+		// kerning
+		state->x += (float)stbtt_GetCodepointKernAdvance(&font->stb_info, (int)state->prev_char, (int)c)
+			* stbtt_ScaleForPixelHeight(&font->stb_info, font->char_height);
+	}
+	
 	{
 		float x, y;
 		x = (float)(state->x - floor(state->x));
 		y = (float)(state->y - floor(state->y));
 		y += char_height * 0.75f;
-		stbtt_GetPackedQuad(&info.data, FONT_TEXTURE_WIDTH, FONT_TEXTURE_HEIGHT, 0, &x, &y, &q, 1);
+		stbtt_GetPackedQuad(&info.data, FONT_TEXTURE_WIDTH, FONT_TEXTURE_HEIGHT, 0, &x, &y, &q, 0);
 		y -= char_height * 0.75f;
 		
 		q.x0 += (float)floor(state->x);
@@ -411,8 +418,8 @@ top:
 	
 	float s0 = q.s0, t0 = q.t0;
 	float s1 = q.s1, t1 = q.t1;
-	float x0 = q.x0, y0 = q.y0;
-	float x1 = q.x1, y1 = q.y1;
+	float x0 = roundf(q.x0), y0 = roundf(q.y0);
+	float x1 = roundf(q.x1), y1 = roundf(q.y1);
 	const float min_x = state->min_x, max_x = state->max_x;
 	const float min_y = state->min_y, max_y = state->max_y;
 	
@@ -460,6 +467,7 @@ top:
 		state->x_largest = state->x;
 	if (state->y > state->y_largest)
 		state->y_largest = state->y;
+	state->prev_char = c;
 }
 
 void text_utf8_with_state(Font *font, TextRenderState *state, const char *str) {
@@ -553,6 +561,10 @@ static void font_free_textures(Font *font) {
 	arr_clear(font->textures);
 }
 
+void text_state_break_kerning(TextRenderState *state) {
+	state->prev_char = 0;
+}
+
 void text_font_change_size(Font *font, float new_size) {
 	font_free_textures(font);
 	font_free_char_info(font);
diff --git a/text.h b/text.h
index 8d317e8..ff07e79 100644
--- a/text.h
+++ b/text.h
@@ -41,6 +41,9 @@ typedef struct {
 	/// largest y achieved (for computing size)
 	double y_largest;
 	
+	/// previous character rendered, or 0 if this is the first
+	char32_t prev_char;
+	
 	/// used for forwards-compatibility
 	char _reserved[64];
 } TextRenderState;
@@ -98,6 +101,11 @@ void text_utf8_anchored(Font *font, const char *text, double x, double y, u32 co
 void text_char_with_state(Font *font, TextRenderState *state, char32_t c);
 /// Draw some UTF-8 text with a \ref TextRenderState.
 void text_utf8_with_state(Font *font, TextRenderState *state, const char *str);
+/// Used to indicate that the next character drawn should not
+/// kern with the previous character.
+///
+/// Use this when you go to the next line or something.
+void text_state_break_kerning(TextRenderState *state);
 /// Free memory used by font.
 ///
 /// Does NOT free the font's fallback.
diff --git a/ui.c b/ui.c
index 0c398b3..abcfad7 100644
--- a/ui.c
+++ b/ui.c
@@ -160,6 +160,7 @@ void selector_render(Ted *ted, Selector *s) {
 			
 			// draw name
 			rgba_u32_to_floats(entry->color, text_state.color);
+			text_state_break_kerning(&text_state);
 			text_utf8_with_state(font, &text_state, entry->name);
 			
 			if (entry->detail) {