tk: Add label widget

2 files changed, 138 insertions, 0 deletions

diff --git a/src/tk/label.c b/src/tk/label.c
new file mode 100644
index 0000000..e9ae38c
--- /dev/null
+++ b/src/tk/label.c
@@ -0,0 +1,137 @@
+/*
+ * Copyright (C) 2021  P. J. McDermott
+ *
+ * This file is part of Maze Fight
+ *
+ * Maze Fight is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Maze Fight is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Maze Fight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <SDL.h>
+#include <SDL_ttf.h>
+#include "../tk.h"
+#include "widget.h"
+
+struct mftk_label {
+	struct mftk_widget  parent;
+	SDL_Texture        *texture;
+	int                 y;
+	int                 h;
+};
+
+static void
+_mftk_label_layout(struct mftk_widget *w __attribute__((__unused__)))
+{
+	/* Size set in constructor */
+}
+
+static int
+_mftk_label_event(struct mftk_widget *w __attribute__((__unused__)),
+		SDL_Event *e __attribute__((__unused__)))
+{
+	/* No events */
+	return 0;
+}
+
+static int
+_mftk_label_render(struct mftk_widget *w, SDL_Renderer *renderer, int x, int y)
+{
+	struct mftk_label *l = (struct mftk_label *) w;
+	SDL_Rect           rect;
+
+	rect.x =        x;
+	rect.y = l->y + y;
+	rect.w = w->w;
+	rect.h = l->h;
+
+	if (SDL_RenderCopy(renderer, l->texture, NULL, &rect) < 0) {
+		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+				"Couldn't render widget: %s",
+				SDL_GetError());
+		return -1;
+	}
+
+	return 0;
+}
+
+static void
+_mftk_label_destroy(struct mftk_widget *w)
+{
+	struct mftk_label *l = (struct mftk_label *) w;
+
+	SDL_DestroyTexture(l->texture);
+}
+
+struct mftk_widget *
+mftk_label_new(TTF_Font *font, const char *text, SDL_Color *color,
+		SDL_Renderer *renderer)
+{
+	struct mftk_widget *w;
+	struct mftk_label  *l;
+	SDL_Surface        *surface;
+	int                 line_skip;
+	int                 ascent;
+	int                 max_y;
+	const char         *c;
+	int                 glyph_max_y;
+
+	if ((w = mftk_widget_new(sizeof(*l))) == NULL) return NULL;
+	l = (struct mftk_label *) w;
+	w->layout  = &_mftk_label_layout;
+	w->event   = &_mftk_label_event;
+	w->render  = &_mftk_label_render;
+	w->destroy = &_mftk_label_destroy;
+
+	surface = TTF_RenderUTF8_Blended(font, text, *color);
+	if (surface == NULL) {
+		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+				"Couldn't create surface: %s",
+				TTF_GetError());
+		free(l);
+		return NULL;
+	}
+
+	l->texture = SDL_CreateTextureFromSurface(renderer, surface);
+	if (l->texture == NULL) {
+		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+				"Couldn't create texture: %s",
+				SDL_GetError());
+		SDL_FreeSurface(surface);
+		free(l);
+		return NULL;
+	}
+
+	line_skip = TTF_FontLineSkip(font);
+	ascent    = TTF_FontAscent  (font);
+	max_y = 0;
+	for (c = text; *c != '\0'; ++c) {
+		if (TTF_GlyphMetrics(font, *c, NULL, NULL, NULL, &glyph_max_y,
+					NULL) < 0) {
+			SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+					"Couldn't get glyph metrics: %s",
+					SDL_GetError());
+			continue;
+		}
+		if (glyph_max_y > max_y) {
+			max_y = glyph_max_y;
+		}
+	}
+	w->w = surface->w;
+	w->h = line_skip;
+	l->y = (line_skip - ascent) / 2 + (ascent - max_y);
+	l->h = surface->h;
+
+	SDL_FreeSurface(surface);
+
+	return w;
+}
diff --git a/src/tk/local.mk b/src/tk/local.mk
index 39b1226..0c37299 100644
--- a/src/tk/local.mk
+++ b/src/tk/local.mk
@@ -1,3 +1,4 @@
 mazefight_SOURCES += \
+	%reldir%/label.c \
 	%reldir%/widget.c \
 	%reldir%/widget.h