display: add a maximum size parameter to dtext_opt()

This parameter controls the maximum number of glyphs to print.

For backwards compatibility, it is automatically inserted by a macro in
older calls with only 7 parameters.

include/gint/display.h

@@ -303,9 +303,16 @@ enum {
             fx-CG 50: Any R5G6B6 color, or C_NONE
    @halign  Where x should be relative to the rendered string
    @valign  Where y should be relative to the rendered string
-   @str     String to display */
+   @str     String to display
+   @size    Maximum number of bytes to display (negative for no limit) */
 void dtext_opt(int x, int y, int fg, int bg, int halign, int valign,
-	char const *str);
+	char const *str, int size);
+
+/* The last parameter @size was added in gint 2.4; this macro will add it
+   automatically with a value of -1 if the call is made with only 7 parameters.
+   This is for backwards compatibility. */
+#define dtext_opt8(x,y,fg,bg,h,v,str,sz,...) dtext_opt(x,y,fg,bg,h,v,str,sz)
+#define dtext_opt(...) dtext_opt8(__VA_ARGS__, -1)
 
 /* dtext(): Simple version of dtext_opt() with defaults
    Calls dtext_opt() with bg=C_NONE, halign=DTEXT_LEFT and valign=DTEXT_TOP. */

src/gray/gtext.c

@@ -4,7 +4,7 @@
 
 /* gtext_opt(): Display a string of text */
 void gtext_opt(int x, int y, int fg, int bg, int halign, int valign,
-	char const *str)
+	char const *str, int size)
 {
 	uint32_t *light, *dark;
 	dgray_getvram(&light, &dark);
@@ -21,5 +21,5 @@ void gtext_opt(int x, int y, int fg, int bg, int halign, int valign,
 	}
 
 	topti_render(x, y, str, topti_font, topti_asm_text[fg],
-		topti_asm_text[bg], light, dark);
+		topti_asm_text[bg], light, dark, size);
 }

src/render-cg/topti.c

@@ -43,9 +43,10 @@ static void topti_glyph(uint16_t *vram, uint32_t const * data, int left,
 }
 
 static void topti_render(int x, int y, char const *str_char, font_t const *f,
-	int fg, int bg)
+	int fg, int bg, int size)
 {
 	uint8_t const *str = (void *)str_char;
+	uint8_t const *str0 = str;
 
 	/* Raw glyph data */
 	uint32_t const *data = f->data;
@@ -68,7 +69,7 @@ static void topti_render(int x, int y, char const *str_char, font_t const *f,
 	while(1)
 	{
 		uint32_t code_point = topti_utf8_next(&str);
-		if(!code_point) break;
+		if(!code_point || (size >= 0 && str - str0 > size)) break;
 
 		int glyph = topti_glyph_index(f, code_point);
 		if(glyph < 0) continue;
@@ -107,12 +108,12 @@ static void topti_render(int x, int y, char const *str_char, font_t const *f,
 
 /* dtext_opt(): Display a string of text */
 void dtext_opt(int x, int y, int fg, int bg, int halign, int valign,
-	char const *str)
+	char const *str, int size)
 {
 	if(halign != DTEXT_LEFT || valign != DTEXT_TOP)
 	{
 		int w, h;
-		dsize(str, topti_font, &w, &h);
+		dnsize(str, size, topti_font, &w, &h);
 
 		if(halign == DTEXT_RIGHT)  x -= w - 1;
 		if(halign == DTEXT_CENTER) x -= (w >> 1);
@@ -120,5 +121,5 @@ void dtext_opt(int x, int y, int fg, int bg, int halign, int valign,
 		if(valign == DTEXT_MIDDLE) y -= (h >> 1);
 	}
 
-	topti_render(x, y, str, topti_font, fg, bg);
+	topti_render(x, y, str, topti_font, fg, bg, size);
 }

src/render-fx/render-fx.h

@@ -74,7 +74,7 @@ struct rendering_mode
 	/* Text and image rendering */
 	void (*dtext_opt)
 		(int x, int y, int fg, int bg, int halign, int valign,
-		 char const *str);
+		 char const *str, int size);
 	void (*dsubimage)
 		(bopti_image_t const *image, struct rbox *r, int flags);
 };
@@ -89,9 +89,8 @@ void grect(int x1, int y1, int x2, int y2, color_t color);
 void gpixel(int x, int y, color_t color);
 void gint_ghline(int x1, int x2, int y, int color);
 void gint_gvline(int y1, int y2, int x, int color);
-void gtext_opt
+void gtext_opt(int x, int y, int fg, int bg, int halign, int valign,
-	(int x, int y, int fg, int bg, int halign, int valign,
+	 char const *str, int size);
-	 char const *str);
 void gsubimage(bopti_image_t const *image, struct rbox *r, int flags);
 
 /* Short macro to call the alternate rendering function when available */

src/render-fx/topti-asm.h

@@ -22,8 +22,10 @@ extern asm_text_t *topti_asm_text[8];
    @asm_fg  Assembler function for text rendering
    @asm_bg  Assembler function for background rendering
    @v1      Monochrome VRAM or light gray VRAM
-   @v2      Monochrome or dark gray VRAM */
+   @v2      Monochrome or dark gray VRAM
+   @size    Maximum number of characters to render */
 void topti_render(int x, int y, char const *str, font_t const *f,
-	asm_text_t *asm_fg, asm_text_t *asm_bg, uint32_t *v1, uint32_t *v2);
+	asm_text_t *asm_fg, asm_text_t *asm_bg, uint32_t *v1, uint32_t *v2,
+	int size);
 
 #endif /* GINT_RENDERFX_TOPTIASM */

src/render-fx/topti.c

@@ -6,6 +6,8 @@
 #include "render-fx.h"
 #include "topti-asm.h"
 
+#undef dtext_opt
+
 /* Default font */
 extern font_t gint_font5x7;
 font_t const * gint_default_font = &gint_font5x7;
@@ -83,9 +85,11 @@ static int topti_split(uint32_t const * glyph, int width, int height, int free,
 
 /* topti_render(): Render a string on the VRAM */
 void topti_render(int x, int y, char const *str_char, font_t const *f,
-	asm_text_t *asm_fg, asm_text_t *asm_bg, uint32_t *v1, uint32_t *v2)
+	asm_text_t *asm_fg, asm_text_t *asm_bg, uint32_t *v1, uint32_t *v2,
+	int size)
 {
 	uint8_t const *str = (void *)str_char;
+	uint8_t const *str0 = str;
 
 	/* Storage height and number of free bits in operators[] */
 	int height = f->data_height, free;
@@ -121,7 +125,7 @@ void topti_render(int x, int y, char const *str_char, font_t const *f,
 	while(1)
 	{
 		uint32_t code_point = topti_utf8_next(&str);
-		if(!code_point) break;
+		if(!code_point || (size >= 0 && str - str0 > size)) break;
 
 		int glyph = topti_glyph_index(f, code_point);
 		if(glyph < 0) continue;
@@ -175,16 +179,16 @@ void topti_render(int x, int y, char const *str_char, font_t const *f,
 
 /* dtext_opt(): Display a string of text */
 void dtext_opt(int x, int y, int fg, int bg, int halign, int valign,
-	char const *str)
+	char const *str, int size)
 {
 	if((uint)fg >= 8 || (uint)bg >= 8) return;
 
-	DMODE_OVERRIDE(dtext_opt, x, y, fg, bg, halign, valign, str);
+	DMODE_OVERRIDE(dtext_opt, x, y, fg, bg, halign, valign, str, size);
 
 	if(halign != DTEXT_LEFT || valign != DTEXT_TOP)
 	{
 		int w, h;
-		dsize(str, topti_font, &w, &h);
+		dnsize(str, size, topti_font, &w, &h);
 
 		if(halign == DTEXT_RIGHT)  x -= w - 1;
 		if(halign == DTEXT_CENTER) x -= (w >> 1);
@@ -193,5 +197,5 @@ void dtext_opt(int x, int y, int fg, int bg, int halign, int valign,
 	}
 
 	topti_render(x, y, str, topti_font, topti_asm_text[fg],
-		topti_asm_text[bg], gint_vram, gint_vram);
+		topti_asm_text[bg], gint_vram, gint_vram, size);
 }