splash: Align text by the baseline

And factor out text rendering into a shared interface.

4 files changed, 109 insertions, 33 deletions

diff --git a/src/local.mk b/src/local.mk
index bdde089..a357b2d 100644
--- a/src/local.mk
+++ b/src/local.mk
@@ -7,5 +7,7 @@ mazefight_SOURCES += \
 	%reldir%/maze.h \
 	%reldir%/splash.c \
 	%reldir%/splash.h \
+	%reldir%/ttf.c \
+	%reldir%/ttf.h \
 	%reldir%/util.c \
 	%reldir%/util.h
diff --git a/src/splash.c b/src/splash.c
index f662a0d..c11d76b 100644
--- a/src/splash.c
+++ b/src/splash.c
@@ -25,39 +25,9 @@
 #include "dirs.h"
 #include "maze.h"
 #include "splash.h"
+#include "ttf.h"
 #include "util.h"
 
-static SDL_Texture *
-_mf_splash_text(TTF_Font *font, const char *text, SDL_Color *color,
-		SDL_Renderer *renderer, SDL_Rect *rect)
-{
-	SDL_Surface *surface;
-	SDL_Texture *texture;
-
-	surface = TTF_RenderUTF8_Blended(font, text, *color);
-	if (surface == NULL) {
-		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
-				"Couldn't create surface: %s",
-				TTF_GetError());
-		return NULL;
-	}
-
-	texture = SDL_CreateTextureFromSurface(renderer, surface);
-	if (texture == NULL) {
-		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
-				"Couldn't create texture: %s",
-				SDL_GetError());
-		return NULL;
-	}
-
-	rect->w = surface->w;
-	rect->h = surface->h;
-
-	SDL_FreeSurface(surface);
-
-	return texture;
-}
-
 int
 mf_splash(SDL_Renderer *renderer)
 {
@@ -87,7 +57,7 @@ mf_splash(SDL_Renderer *renderer)
 		free(font_path);
 		return -1;
 	}
-	title_texture = _mf_splash_text(font, "Maze Fight", &text_color,
+	title_texture = mf_ttf_render(font, "Maze Fight", &text_color,
 			renderer, &title_rect);
 	if (title_texture == NULL) {
 		goto err;
@@ -95,7 +65,7 @@ mf_splash(SDL_Renderer *renderer)
 	TTF_CloseFont(font);
 	font = NULL;
 	title_rect.x = (MF_WINDOW_W - title_rect.w) / 2;
-	title_rect.y = MF_SPLASH_WINDOW_P + MF_SPLASH_FORM_P;
+	title_rect.y += MF_SPLASH_WINDOW_P + MF_SPLASH_FORM_P;
 
 	/* TODO: Widgets */
 
diff --git a/src/ttf.c b/src/ttf.c
new file mode 100644
index 0000000..9cfaab0
--- /dev/null
+++ b/src/ttf.c
@@ -0,0 +1,74 @@
+/*
+ * 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 <stdlib.h>
+#include "ttf.h"
+
+SDL_Texture *
+mf_ttf_render(TTF_Font *font, const char *text, SDL_Color *color,
+		SDL_Renderer *renderer, SDL_Rect *rect)
+{
+	SDL_Surface *surface;
+	SDL_Texture *texture;
+	int          ascent;
+	int          max_y;
+	const char  *c;
+	int          glyph_max_y;
+
+	surface = TTF_RenderUTF8_Blended(font, text, *color);
+	if (surface == NULL) {
+		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+				"Couldn't create surface: %s",
+				TTF_GetError());
+		return NULL;
+	}
+
+	texture = SDL_CreateTextureFromSurface(renderer, surface);
+	if (texture == NULL) {
+		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+				"Couldn't create texture: %s",
+				SDL_GetError());
+		return NULL;
+	}
+
+	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;
+		}
+	}
+	rect->x = 0;
+	rect->y = ascent - max_y;
+	rect->w = surface->w;
+	rect->h = surface->h;
+
+	SDL_FreeSurface(surface);
+
+	return texture;
+}
diff --git a/src/ttf.h b/src/ttf.h
new file mode 100644
index 0000000..5254eb2
--- /dev/null
+++ b/src/ttf.h
@@ -0,0 +1,30 @@
+/*
+ * 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/>.
+ */
+
+#ifndef MF_TTF_H_
+#define MF_TTF_H_
+
+#include <SDL.h>
+
+SDL_Texture *
+mf_ttf_render(TTF_Font *font, const char *text, SDL_Color *color,
+		SDL_Renderer *renderer, SDL_Rect *rect);
+
+#endif  /* MF_TTF_H_ */
+