moonlight-chrome/gamepad.cpp

#include "moonlight.hpp"

#include "ppapi/c/ppb_gamepad.h"

#include <Limelight.h>

static const unsigned short k_XInputButtonMapping[] = {
    A_FLAG, B_FLAG, X_FLAG, Y_FLAG,
    LB_FLAG, RB_FLAG,
    0, 0, // Triggers
    BACK_FLAG, PLAY_FLAG,
    LS_CLK_FLAG, RS_CLK_FLAG,
    UP_FLAG, DOWN_FLAG, LEFT_FLAG, RIGHT_FLAG
};

static const unsigned int k_XInputTriggerButtonIndexes[] = {
    6, 7
};

void MoonlightInstance::PollGamepads() {
    PP_GamepadsSampleData gamepadData;
    
    m_GamepadApi->Sample(pp_instance(), &gamepadData);
    
    for (unsigned int p = 0; p < gamepadData.length; p++) {
        PP_GamepadSampleData& padData = gamepadData.items[p];
        
        if (!padData.connected) {
            // Not connected
            continue;
        }
        
        if (padData.timestamp == m_LastPadTimestamps[p]) {
            // No change from last poll
            continue;
        }
        
        m_LastPadTimestamps[p] = padData.timestamp;
        
        short buttonFlags = 0;
        unsigned char leftTrigger = 0, rightTrigger = 0;
        short leftStickX = 0, leftStickY = 0;
        short rightStickX = 0, rightStickY = 0;
        
        // Handle buttons and triggers
        for (unsigned int i = 0; i < padData.buttons_length; i++) {
            if (i >= sizeof(k_XInputButtonMapping) / sizeof(k_XInputButtonMapping[0])) {
                // Ignore unmapped buttons
                break;
            }
            
            // Handle triggers first
            if (i == k_XInputTriggerButtonIndexes[0]) {
                leftTrigger = padData.buttons[i] * 0xFF;
            }
            else if (i == k_XInputTriggerButtonIndexes[1]) {
                rightTrigger = padData.buttons[i] * 0xFF;
            }
            // Now normal buttons
            else if (padData.buttons[i] > 0.5f) {
                buttonFlags |= k_XInputButtonMapping[i];
            }
        }
        
        // Get left stick values
        if (padData.axes_length >= 2) {
            leftStickX = padData.axes[0] * 0x7FFF;
            leftStickY = -padData.axes[1] * 0x7FFF;
        }
        
        // Get right stick values
        if (padData.axes_length >= 4) {
            rightStickX = padData.axes[2] * 0x7FFF;
            rightStickY = -padData.axes[3] * 0x7FFF;
        }
        
        LiSendMultiControllerEvent(p, buttonFlags, leftTrigger, rightTrigger,
                                   leftStickX, leftStickY, rightStickX, rightStickY);
    }
}