allow force-loading a built-in charset

asiekierka · Nov 7, 2021 · 96a938f · 96a938f
1 parent b242cca
commit 96a938f
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Showing 3 changed files with 30 additions and 0 deletions.
diff --git a/src/frontend_posix.c b/src/frontend_posix.c
@@ -44,6 +44,7 @@ static void posix_zzt_help(int argc, char **argv) {
 	fprintf(stderr, "         available types/formats: \n");
 	fprintf(stderr, "         - charset:\n");
 	fprintf(stderr, "             - chr (MegaZeux-like; 8x[height], 256 chars)\n");
+	fprintf(stderr, "             - default (builtin font; ega or cga)\n");
 	fprintf(stderr, "         - palette:\n");
 	fprintf(stderr, "             - pal (MegaZeux-like; 16 colors ranged 00-3F)\n");
 	fprintf(stderr, "             - pld (Toshiba UPAL; 64 EGA colors ranged 00-3F)\n");
@@ -163,6 +164,15 @@ static int posix_zzt_init(int argc, char **argv) {
 			type[filename - type - 1] = '\0';
 		}
 
+		if (strcmp(type, "charset:default") == 0) {
+			if (strcmp(filename, "ega") == 0) {
+				zzt_force_default_charset(DEFAULT_CHARSET_STYLE_EGA);
+			} else if (strcmp(filename, "cga") == 0) {
+				zzt_force_default_charset(DEFAULT_CHARSET_STYLE_CGA);
+			}
+			continue;
+		}
+
 		FILE *file = fopen(filename, "rb");
 		if (!file) {
 			fprintf(stderr, "Could not open %s!\n", filename);

diff --git a/src/zzt.c b/src/zzt.c
@@ -277,6 +277,19 @@ static void zzt_load_charset_default() {
 	}
 }
 
+USER_FUNCTION
+void zzt_force_default_charset(zzt_default_charset_style_t style) {
+	if (style == DEFAULT_CHARSET_STYLE_CGA) {
+		zzt_load_charset(8, 16, res_8x8dbl_bin, true);
+	} else if (style == DEFAULT_CHARSET_STYLE_EGA) {
+		zzt_load_charset(8, 14, res_8x14_bin, true);
+	} else {
+		return;
+	}
+
+	zzt.charset_default = false;
+}
+
 static u16 cpu_func_port_in_main(cpu_state* cpu, u16 addr) {
 	zzt_state* zzt = (zzt_state*) cpu;
 

diff --git a/src/zzt.h b/src/zzt.h
@@ -30,6 +30,11 @@
 #define MAX_FILES 16
 #define TEXT_ADDR(x,y) (0xB8000 + ((y)*160) + ((x)*2))
 
+typedef enum {
+	DEFAULT_CHARSET_STYLE_EGA,
+	DEFAULT_CHARSET_STYLE_CGA
+} zzt_default_charset_style_t;
+
 // the long story:
 // 3.579545 MHz - NTSC dotclock
 // dotclock * 4 = 14.31818
@@ -97,6 +102,8 @@ int zzt_get_blink(void);
 USER_FUNCTION
 int zzt_load_charset(int width, int height, u8* data, bool is_default);
 USER_FUNCTION
+void zzt_force_default_charset(zzt_default_charset_style_t style);
+USER_FUNCTION
 int zzt_load_palette(u32* colors);
 USER_FUNCTION
 int zzt_load_ega_palette(u8* colors);