Improve text width calculation precision (#1408)

In some extreme cases (~30000 chars) text width precision takes a hit.
Using double instead of float fixes that.

src/api/renderer.c

@@ -345,7 +345,7 @@ static int f_draw_text(lua_State *L) {
 
   size_t len;
   const char *text = luaL_checklstring(L, 2, &len);
-  float x = luaL_checknumber(L, 3);
+  double x = luaL_checknumber(L, 3);
   int y = luaL_checknumber(L, 4);
   RenColor color = checkcolor(L, 5, 255);
   x = rencache_draw_text(&window_renderer, fonts, text, len, x, y, color);

src/rencache.c

@@ -191,9 +191,9 @@ void rencache_draw_rect(RenRect rect, RenColor color) {
   }
 }
 
-float rencache_draw_text(RenWindow *window_renderer, RenFont **fonts, const char *text, size_t len, float x, int y, RenColor color)
+double rencache_draw_text(RenWindow *window_renderer, RenFont **fonts, const char *text, size_t len, double x, int y, RenColor color)
 {
-  float width = ren_font_group_get_width(window_renderer, fonts, text, len);
+  double width = ren_font_group_get_width(window_renderer, fonts, text, len);
   RenRect rect = { x, y, (int)width, ren_font_group_get_height(fonts) };
   if (rects_overlap(last_clip_rect, rect)) {
     int sz = len + 1;

src/rencache.h

@@ -8,7 +8,7 @@
 void  rencache_show_debug(bool enable);
 void  rencache_set_clip_rect(RenRect rect);
 void  rencache_draw_rect(RenRect rect, RenColor color);
-float rencache_draw_text(RenWindow *window_renderer, RenFont **font, const char *text, size_t len, float x, int y, RenColor color);
+double rencache_draw_text(RenWindow *window_renderer, RenFont **font, const char *text, size_t len, double x, int y, RenColor color);
 void  rencache_invalidate(void);
 void  rencache_begin_frame(RenWindow *window_renderer);
 void  rencache_end_frame(RenWindow *window_renderer);

src/renderer.c

@@ -360,8 +360,8 @@ int ren_font_group_get_height(RenFont **fonts) {
   return fonts[0]->height;
 }
 
-float ren_font_group_get_width(RenWindow *window_renderer, RenFont **fonts, const char *text, size_t len) {
+double ren_font_group_get_width(RenWindow *window_renderer, RenFont **fonts, const char *text, size_t len) {
-  float width = 0;
+  double width = 0;
   const char* end = text + len;
   GlyphMetric* metric = NULL; GlyphSet* set = NULL;
   while (text < end) {
@@ -376,12 +376,12 @@ float ren_font_group_get_width(RenWindow *window_renderer, RenFont **fonts, cons
   return width / surface_scale;
 }
 
-float ren_draw_text(RenWindow *window_renderer, RenFont **fonts, const char *text, size_t len, float x, int y, RenColor color) {
+double ren_draw_text(RenWindow *window_renderer, RenFont **fonts, const char *text, size_t len, float x, int y, RenColor color) {
   SDL_Surface *surface = renwin_get_surface(window_renderer);
   const RenRect clip = window_renderer->clip;
 
   const int surface_scale = renwin_surface_scale(window_renderer);
-  float pen_x = x * surface_scale;
+  double pen_x = x * surface_scale;
   y *= surface_scale;
   int bytes_per_pixel = surface->format->BytesPerPixel;
   const char* end = text + len;
@@ -389,7 +389,7 @@ float ren_draw_text(RenWindow *window_renderer, RenFont **fonts, const char *tex
   int clip_end_x = clip.x + clip.width, clip_end_y = clip.y + clip.height;
 
   RenFont* last = NULL;
-  float last_pen_x = x;
+  double last_pen_x = x;
   bool underline = fonts[0]->style & FONT_STYLE_UNDERLINE;
   bool strikethrough = fonts[0]->style & FONT_STYLE_STRIKETHROUGH;
 
@@ -453,7 +453,7 @@ float ren_draw_text(RenWindow *window_renderer, RenFont **fonts, const char *tex
 
     if(!last) last = font;
     else if(font != last || text == end) {
-      float local_pen_x = text == end ? pen_x + adv : pen_x;
+      double local_pen_x = text == end ? pen_x + adv : pen_x;
       if (underline)
         ren_draw_rect(window_renderer, (RenRect){last_pen_x, y / surface_scale + last->height - 1, (local_pen_x - last_pen_x) / surface_scale, last->underline_thickness * surface_scale}, color);
       if (strikethrough)

src/renderer.h

@@ -33,8 +33,8 @@ int ren_font_group_get_height(RenFont **font);
 float ren_font_group_get_size(RenFont **font);
 void ren_font_group_set_size(RenWindow *window_renderer, RenFont **font, float size);
 void ren_font_group_set_tab_size(RenFont **font, int n);
-float ren_font_group_get_width(RenWindow *window_renderer, RenFont **font, const char *text, size_t len);
+double ren_font_group_get_width(RenWindow *window_renderer, RenFont **font, const char *text, size_t len);
-float ren_draw_text(RenWindow *window_renderer, RenFont **font, const char *text, size_t len, float x, int y, RenColor color);
+double ren_draw_text(RenWindow *window_renderer, RenFont **font, const char *text, size_t len, float x, int y, RenColor color);
 
 void ren_draw_rect(RenWindow *window_renderer, RenRect rect, RenColor color);