Create text module for displaying messages

build.sh

@@ -8,4 +8,4 @@ defs="-D_POSIX_C_SOURCE=200809L"
 
 $cc $warn $flags $libs $defs \
 	-o asteroids \
-	fb.c game.c input.c main.c maths.c renderer.c rng.c
+	fb.c game.c input.c main.c maths.c renderer.c rng.c text.c

game.c

@@ -2,6 +2,7 @@
 
 #include "input.h"
 #include "renderer.h"
+#include "text.h"
 #include "rng.h"
 
 #include <assert.h>
@@ -51,10 +52,7 @@
 #define MAX_SHAPES_PER_ENTITY 2
 #define MAX_COLLISIONS 128U
 
-#define GAME_OVER_WIDTH 24
-#define GAME_OVER_HEIGHT 8
-#define GAME_OVER_SCALE 0.025
-#define GAME_OVER_COUNTER_MASK (1 << 6)
+#define COUNTER_MASK (1 << 6)
 
 #define NELEMS(arr) (sizeof(arr) / sizeof(arr[0]))
 
@@ -103,40 +101,6 @@ static const vec2_t fire_verts[] = {
 };
 static const vec2_t shot_verts[] = { { 0.0, -0.02 }, { 0.0, 0.02 } };
 
-static const vec2_t game_over_verts[][MAX_VERTS] = {
-	// G
-	{ { -10, 4 }, { -12, 4 }, { -12, -4 }, { -10, -4 }, { -10, 0 } },
-	// A
-	{ { -9, -4 }, { -8, 4 }, { -7, -4 } },
-	{ { -8.75, -2 }, { -7.25, -2 } },
-	// M
-	{ { -6, -4 }, { -6, 4 }, { -5, -4 }, { -4, 4 }, { -4, -4 } },
-	// E
-	{ { -1, 4 }, { -3, 4 }, { -3, -4 }, { -1, -4 } },
-	{ { -3, 0 }, { -2, 0 } },
-	// O
-	{ { 1, 4 }, { 1, -4 }, { 3, -4 }, { 3, 4 }, { 1, 4 } },
-	// V
-	{ { 4, 4 }, { 5, -4 }, { 6, 4 } },
-	// E
-	{ { 9, 4 }, { 7, 4 }, { 7, -4 }, { 9, -4 } },
-	{ { 7, 0 }, { 8, 0 } },
-	// R
-	{ { 10, -4 }, { 10, 4 }, { 12, 4 }, { 12, -2 }, { 10, -2 }, { 12, -4 } },
-};
-static const unsigned game_over_lens[NELEMS(game_over_verts)] = {
-	5, 3, 2, 5, 4, 2, 5, 3, 4, 2, 6,
-};
-static const mat3_t game_over_transform = {
-	{ GAME_OVER_SCALE, 0, 0 },
-	{ 0, GAME_OVER_SCALE, 0 },
-	{ 0, 0, 1 },
-};
-static const vec2_t game_over_bg = {
-	.x = (GAME_OVER_WIDTH + 2) * GAME_OVER_SCALE,
-	.y = (GAME_OVER_HEIGHT + 2) * GAME_OVER_SCALE,
-};
-
 static entity_t entities[MAX_ENTITIES];
 static mat3_t transforms[MAX_ENTITIES];
 static shape_t shapes[MAX_SHAPES];
@@ -530,12 +494,6 @@ void game_draw()
 		    shapes[i].connect);
 	}
 
-	if (dead && !(counter & GAME_OVER_COUNTER_MASK)) {
-		renderer_clear_rect((vec2_t) { 0, 0 }, game_over_bg);
-		for (unsigned i = 0; i < NELEMS(game_over_verts); ++i) {
-			renderer_draw(
-			    game_over_verts[i], game_over_lens[i], game_over_transform,
-			    false);
-		}
-	}
+	if (dead && !(counter & COUNTER_MASK))
+		text_draw("GAME OVER");
 }

text.c

@@ -0,0 +1,117 @@
+#include "text.h"
+
+#include "renderer.h"
+
+#include <assert.h>
+
+#define NELEMS(arr) (sizeof(arr) / sizeof(arr[0]))
+
+#define MAX_LINES 2
+
+#define TEXT_HEIGHT 8
+#define TEXT_SCALE 0.025
+#define LETTER_WIDTH 3
+#define SPACE_WIDTH 1
+
+typedef struct {
+	unsigned line_count;
+	unsigned line_lens[MAX_LINES];
+	vec2_t lines[MAX_LINES][MAX_VERTS];
+} glyph_t;
+
+static const mat3_t text_transform = {
+	{ TEXT_SCALE, 0, 0 },
+	{ 0, TEXT_SCALE, 0 },
+	{ 0, 0, 1 },
+};
+
+static const glyph_t font[] = {
+	['A'] = {
+		.line_count = 2,
+		.line_lens = { 3, 2 },
+		.lines = {
+			{ { -1, -4 }, { 0, 4 }, { 1, -4 } },
+			{ { -0.75, -2 }, { 0.75, -2 } },
+		},
+	},
+	['E'] = {
+		.line_count = 2,
+		.line_lens = { 4, 2 },
+		.lines = {
+			{ { 1, 4 }, { -1, 4 }, { -1, -4 }, { 1, -4 } },
+			{ { -1, -2 }, { 0, -2 } },
+		},
+	},
+	['G'] = {
+		.line_count = 1,
+		.line_lens = { 5 },
+		.lines = {
+			{ { 1, 4 }, { -1, 4 }, { -1, -4 }, { 1, -4 }, { 1, -2 } },
+		},
+	},
+	['M'] = {
+		.line_count = 1,
+		.line_lens = { 5 },
+		.lines = {
+			{ { -1, -4 }, { -1, 4 }, { 0, -4 }, { 1, 4 }, { 1, -4 } },
+		},
+	},
+	['O'] = {
+		.line_count = 1,
+		.line_lens = { 5 },
+		.lines = {
+			{ { -1, 4 }, { -1, -4 }, { 1, -4 }, { 1, 4 }, { -1, 4 } },
+		},
+	},
+	['R'] = {
+		.line_count = 1,
+		.line_lens = { 6 },
+		.lines = {
+			{
+				{ -1, -4 }, { -1, 4 }, { 1, 4 },
+				{ 1, -2 }, { -1, -2 }, { 1, -4 },
+			},
+		},
+	},
+	['V'] = {
+		.line_count = 1,
+		.line_lens = { 3 },
+		.lines = {
+			{ { -1, 4 }, { 0, -4 }, { 1, 4 } },
+		},
+	},
+};
+
+void text_draw(const char *s)
+{
+	int width = 0;
+	for (const char *p = s; *p != '\0'; ++p)
+		width += *p == ' ' ? SPACE_WIDTH : LETTER_WIDTH;
+	--width;
+
+	const vec2_t bg_size = {
+		.x = TEXT_SCALE * (width + 2),
+		.y = TEXT_SCALE * (TEXT_HEIGHT + 2),
+	};
+	renderer_clear_rect((vec2_t) { 0, 0 }, bg_size);
+
+	int x = -width / 2 + 1;
+	for (const char *p = s; *p != '\0'; ++p) {
+		if (*p == ' ') {
+			x += SPACE_WIDTH;
+		} else {
+			const unsigned c = (unsigned)*p;
+			assert(c < NELEMS(font) && font[c].line_count != 0);
+			const glyph_t *g = font + c;
+
+			const vec2_t t = { .x = x };
+			const mat3_t m
+			    = mat3_mul_mat3(text_transform, mat3_translation(t));
+
+			for (unsigned i = 0; i < g->line_count; ++i)
+				renderer_draw(g->lines[i], g->line_lens[i], m, false);
+
+			x += LETTER_WIDTH;
+		}
+	}
+}

text.h

@@ -0,0 +1,6 @@
+#ifndef TEXT_H
+#define TEXT_H
+
+void text_draw(const char *s);
+
+#endif