Allow user to use NN scaling at integer scales

While linear/anisotropic filtering introduces in previous commit looks
good at non-integer scales, using it at integer scales may make screen
look unnecessarily blurry. This commit introduces an option to use NN
scaling at integer values of scale.

data/language/english_uk.txt

@@ -4029,13 +4029,13 @@ STR_5723    :Heavy Rain
 STR_5724    :Thunderstorm
 STR_5725    :{BLACK}Force weather:
 STR_5726    :{SMALLFONT}{BLACK}Sets the current weather in park
-
 STR_5727    :Scaling quality
 STR_5728    :Requires hardware display option
 STR_5729    :{SMALLFONT}{BLACK}Requires hardware display option
 STR_5730    :Nearest neighbour
 STR_5731    :Linear
 STR_5732    :Anisotropic
+STR_5733    :Use NN scaling at integer scales
 
 #############
 # Scenarios #

src/config.c

@@ -206,6 +206,7 @@ config_property_definition _generalDefinitions[] = {
 	{ offsetof(general_configuration, steam_overlay_pause),				"steam_overlay_pause",			CONFIG_VALUE_TYPE_BOOLEAN,		true,							NULL					},
 	{ offsetof(general_configuration, window_scale),					"window_scale",					CONFIG_VALUE_TYPE_FLOAT,		{ .value_float = 1.0f },		NULL					},
 	{ offsetof(general_configuration, scale_quality),					"scale_quality",				CONFIG_VALUE_TYPE_UINT8,		1,								NULL					},
+	{ offsetof(general_configuration, use_nn_at_integer_scales),		"use_nn_at_integer_scales",		CONFIG_VALUE_TYPE_BOOLEAN,		true,							NULL					},
 	{ offsetof(general_configuration, show_fps),						"show_fps",						CONFIG_VALUE_TYPE_BOOLEAN,		false,							NULL					},
 	{ offsetof(general_configuration, trap_cursor),						"trap_cursor",					CONFIG_VALUE_TYPE_BOOLEAN,		false,							NULL					},
 	{ offsetof(general_configuration, auto_open_shops),					"auto_open_shops",				CONFIG_VALUE_TYPE_BOOLEAN,		false,							NULL					},

src/config.h

@@ -178,6 +178,7 @@ typedef struct {
 	uint8 steam_overlay_pause;
 	float window_scale;
 	uint8 scale_quality;
+	uint8 use_nn_at_integer_scales;
 	uint8 show_fps;
 	uint8 trap_cursor;
 	uint8 auto_open_shops;

src/localisation/string_ids.h

@@ -2328,6 +2328,7 @@ enum {
 	STR_SCALING_QUALITY_NN = 5730,
 	STR_SCALING_QUALITY_LINEAR = 5731,
 	STR_SCALING_QUALITY_ANISOTROPIC = 5732,
+	STR_USE_NN_AT_INTEGER_SCALE = 5733,
 
 	// Have to include resource strings (from scenarios and objects) for the time being now that language is partially working
 	STR_COUNT = 32768

src/platform/shared.c

@@ -360,9 +360,13 @@ static void platform_resize(int width, int height)
  */
 void platform_trigger_resize()
 {
-	char scale_quality[4]; // just to make sure we can hold whole uint8
+	char scale_quality_buffer[4]; // just to make sure we can hold whole uint8
-	snprintf(scale_quality, sizeof(scale_quality), "%u", gConfigGeneral.scale_quality);
+	uint8 scale_quality = gConfigGeneral.scale_quality;
-	SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, scale_quality);
+	if (gConfigGeneral.use_nn_at_integer_scales && gConfigGeneral.window_scale == floor(gConfigGeneral.window_scale)) {
+		scale_quality = 0;
+	}
+	snprintf(scale_quality_buffer, sizeof(scale_quality_buffer), "%u", scale_quality);
+	SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, scale_quality_buffer);
 
 	int w, h;
 	SDL_GetWindowSize(gWindow, &w, &h);

src/windows/options.c

@@ -88,6 +88,7 @@ enum WINDOW_OPTIONS_WIDGET_IDX {
 	WIDX_SCALE_DOWN,
 	WIDX_SCALE_QUALITY,
 	WIDX_SCALE_QUALITY_DROPDOWN,
+	WIDX_SCALE_USE_NN_AT_INTEGER_SCALES_CHECKBOX,
 	WIDX_RENDERING_GROUP,
 	WIDX_TILE_SMOOTHING_CHECKBOX,
 	WIDX_GRIDLINES_CHECKBOX,
@@ -167,7 +168,7 @@ enum WINDOW_OPTIONS_WIDGET_IDX {
 };
 
 #define WW 			310
-#define WH 			317
+#define WH 			332
 
 #define MAIN_OPTIONS_WIDGETS \
 	{ WWT_FRAME,			0,	0,		WW-1,	0,		WH-1,	STR_NONE,			STR_NONE }, \
@@ -183,7 +184,7 @@ enum WINDOW_OPTIONS_WIDGET_IDX {
 
 static rct_widget window_options_display_widgets[] = {
 	MAIN_OPTIONS_WIDGETS,
-	{ WWT_GROUPBOX,			1,	5,      304,	53,		190,	STR_HARDWARE_GROUP,		STR_NONE },					// Hardware group
+	{ WWT_GROUPBOX,			1,	5,      304,	53,		205,	STR_HARDWARE_GROUP,		STR_NONE },					// Hardware group
 	{ WWT_DROPDOWN,			1,	155,	299,	68,		79,		STR_RESOLUTION_X_BY_Y,	STR_NONE },					// resolution
 	{ WWT_DROPDOWN_BUTTON,	1,	288,	298,	69,		78,		STR_DROPDOWN_GLYPH,		STR_NONE },
 	{ WWT_DROPDOWN,			1,	155,	299,	83,		94,		871,					STR_NONE },					// fullscreen
@@ -198,8 +199,9 @@ static rct_widget window_options_display_widgets[] = {
 	{ WWT_DROPDOWN_BUTTON,	1,	288,	298,	165,	169,	STR_NUMERIC_DOWN,		STR_NONE },					// scale spinner down
 	{ WWT_DROPDOWN,			1,	155,	299,	174,	185,	STR_NONE,				STR_REQUIRES_HW_DISPLAY },	// scaling quality hint
 	{ WWT_DROPDOWN_BUTTON,	1,	288,	298,	175,	184,	STR_DROPDOWN_GLYPH,		STR_REQUIRES_HW_DISPLAY_TIP },
+	{ WWT_CHECKBOX,			1,	10,		290,	189,	200,	STR_USE_NN_AT_INTEGER_SCALE,	STR_NONE },			// use nn scaling at integer scales
 
-#define FRAME_RENDERING_START 194
+#define FRAME_RENDERING_START 209
 	{ WWT_GROUPBOX,			1,	5,      304,	FRAME_RENDERING_START + 0,	FRAME_RENDERING_START + 91,	STR_RENDERING_GROUP,	STR_NONE },					// Rendering group
 	{ WWT_CHECKBOX,			1,	10,		290,	FRAME_RENDERING_START + 15,	FRAME_RENDERING_START + 26,	STR_TILE_SMOOTHING, 	STR_TILE_SMOOTHING_TIP },	// landscape smoothing
 	{ WWT_CHECKBOX,			1,	10,		290,	FRAME_RENDERING_START + 30,	FRAME_RENDERING_START + 41,	STR_GRIDLINES,			STR_GRIDLINES_TIP },		// gridlines
@@ -392,9 +394,10 @@ static uint32 window_options_page_enabled_widgets[] = {
 	(1 << WIDX_SCALE_DOWN) |
 	(1 << WIDX_SCALE_QUALITY) |
 	(1 << WIDX_SCALE_QUALITY_DROPDOWN) |
+	(1 << WIDX_SCALE_USE_NN_AT_INTEGER_SCALES_CHECKBOX) |
 	(1 << WIDX_CONSTRUCTION_MARKER) |
 	(1 << WIDX_CONSTRUCTION_MARKER_DROPDOWN) |
-	(1 << WIDX_DAY_NIGHT_CHECKBOX) |
+	(1u << WIDX_DAY_NIGHT_CHECKBOX) |
 	(1u << WIDX_UPPER_CASE_BANNERS_CHECKBOX),
 
 	MAIN_OPTIONS_ENABLED_WIDGETS |
@@ -564,6 +567,12 @@ static void window_options_mouseup(rct_window *w, int widgetIndex)
 			config_save_default();
 			window_invalidate(w);
 			break;
+		case WIDX_SCALE_USE_NN_AT_INTEGER_SCALES_CHECKBOX:
+			gConfigGeneral.use_nn_at_integer_scales ^= 1;
+			config_save_default();
+			gfx_invalidate_screen();
+			platform_trigger_resize();
+			break;
 		case WIDX_DAY_NIGHT_CHECKBOX:
 			gConfigGeneral.day_night_cycle ^= 1;
 			config_save_default();
@@ -1277,6 +1286,7 @@ static void window_options_invalidate(rct_window *w)
 		widget_set_checkbox_value(w, WIDX_SHOW_FPS_CHECKBOX, gConfigGeneral.show_fps);
 		widget_set_checkbox_value(w, WIDX_MINIMIZE_FOCUS_LOSS, gConfigGeneral.minimize_fullscreen_focus_loss);
 		widget_set_checkbox_value(w, WIDX_STEAM_OVERLAY_PAUSE, gConfigGeneral.steam_overlay_pause);
+		widget_set_checkbox_value(w, WIDX_SCALE_USE_NN_AT_INTEGER_SCALES_CHECKBOX, gConfigGeneral.use_nn_at_integer_scales);
 		widget_set_checkbox_value(w, WIDX_DAY_NIGHT_CHECKBOX, gConfigGeneral.day_night_cycle);
 		widget_set_checkbox_value(w, WIDX_UPPER_CASE_BANNERS_CHECKBOX, gConfigGeneral.upper_case_banners);