From ace1989f734ee7234a6ca12c5f19c5bdfd1fdef2 Mon Sep 17 00:00:00 2001
From: Stuart Kenny
Date: Sat, 1 Feb 2020 13:20:01 +0000
Subject: Add input analog axis range modifier

Add core option to change axis saturation. Square bounds allow controllers that struggle to fully register diagonal deflections . Very helpful with switch joycons and some android controllers.
---
 frontend/libretro.c              | 39 +++++++++++++++++++++++++++++++++++----
 frontend/libretro_core_options.h | 11 +++++++++++
 2 files changed, 46 insertions(+), 4 deletions(-)

(limited to 'frontend')

diff --git a/frontend/libretro.c b/frontend/libretro.c
index 64e4145..b41eca0 100644
--- a/frontend/libretro.c
+++ b/frontend/libretro.c
@@ -126,6 +126,8 @@ int in_enable_vibration = 1;
 static int negcon_deadzone = 0;
 static int negcon_linearity = 1;
 
+static bool axis_bounds_modifier;
+
 /* PSX max resolution is 640x512, but with enhancement it's 1024x512 */
 #define VOUT_MAX_WIDTH 1024
 #define VOUT_MAX_HEIGHT 512
@@ -1643,6 +1645,18 @@ static void update_variables(bool in_flight)
       }
    }
 
+   var.value = NULL;
+   var.key = "pcsx_rearmed_analog_axis_modifier";
+   axis_bounds_modifier = true;
+   if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) || var.value)
+   {
+      if (strcmp(var.value, "square") == 0) {
+        axis_bounds_modifier = true;
+	  } else if (strcmp(var.value, "circle") == 0) {
+        axis_bounds_modifier = false;
+	  }
+   }
+
    var.value = NULL;
    var.key = "pcsx_rearmed_vibration";
 
@@ -2167,6 +2181,23 @@ static uint16_t get_analog_button(int16_t ret, retro_input_state_t input_state_c
 	return button;
 }
 
+unsigned char axis_range_modifier(int16_t axis_value, bool is_square) {
+	float modifier_axis_range = 0;
+
+	if(is_square) {
+		modifier_axis_range = round((axis_value >> 8) / 0.785) + 128;
+		if(modifier_axis_range < 0) {
+			modifier_axis_range = 0;
+		} else if(modifier_axis_range > 255) {
+			modifier_axis_range = 255;
+		}
+	} else {
+		modifier_axis_range = MIN(((axis_value >> 8) + 128), 255);
+	}
+
+	return modifier_axis_range;
+}
+
 void retro_run(void)
 {
 	int i;
@@ -2439,10 +2470,10 @@ void retro_run(void)
 			// Query analog inputs
 			if (in_type[i] == PSE_PAD_TYPE_ANALOGJOY || in_type[i] == PSE_PAD_TYPE_ANALOGPAD)
 			{
-				in_analog_left[i][0] = MIN((input_state_cb(i, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_LEFT, RETRO_DEVICE_ID_ANALOG_X) / 255) + 128, 255);
-				in_analog_left[i][1] = MIN((input_state_cb(i, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_LEFT, RETRO_DEVICE_ID_ANALOG_Y) / 255) + 128, 255);
-				in_analog_right[i][0] = MIN((input_state_cb(i, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_RIGHT, RETRO_DEVICE_ID_ANALOG_X) / 255) + 128, 255);
-				in_analog_right[i][1] = MIN((input_state_cb(i, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_RIGHT, RETRO_DEVICE_ID_ANALOG_Y) / 255) + 128, 255);
+				in_analog_left[i][0] = axis_range_modifier(input_state_cb(i, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_LEFT, RETRO_DEVICE_ID_ANALOG_X), axis_bounds_modifier);
+				in_analog_left[i][1] = axis_range_modifier(input_state_cb(i, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_LEFT, RETRO_DEVICE_ID_ANALOG_Y), axis_bounds_modifier);
+				in_analog_right[i][0] = axis_range_modifier(input_state_cb(i, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_RIGHT, RETRO_DEVICE_ID_ANALOG_X), axis_bounds_modifier);
+				in_analog_right[i][1] = axis_range_modifier(input_state_cb(i, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_RIGHT, RETRO_DEVICE_ID_ANALOG_Y), axis_bounds_modifier);
 			}
 		}
 	}
diff --git a/frontend/libretro_core_options.h b/frontend/libretro_core_options.h
index 53b1095..aa9d3d4 100644
--- a/frontend/libretro_core_options.h
+++ b/frontend/libretro_core_options.h
@@ -266,6 +266,17 @@ struct retro_core_option_definition option_defs_us[] = {
       },
       "linear",
    },
+   {
+      "pcsx_rearmed_analog_axis_modifier",
+      "Analog axis bounds.",
+      "Range bounds for analog axis. Square bounds help controllers with highly circular ranges that are unable to fully saturate the x and y axis at 45degree deflections.",
+      {
+         { "circle", NULL },
+         { "square", NULL },
+         { NULL, NULL },
+      },
+      "circle",
+   },
    {
       "pcsx_rearmed_vibration",
       "Enable Vibration",
-- 
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