SDL/test/gamepadutils.c

/*
  Copyright (C) 1997-2023 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely.
*/
#include <SDL3/SDL.h>
#include <SDL3/SDL_test_font.h>

#include "gamepadutils.h"
#include "gamepad_front.h"
#include "gamepad_back.h"
#include "gamepad_battery_unknown.h"
#include "gamepad_battery_empty.h"
#include "gamepad_battery_low.h"
#include "gamepad_battery_medium.h"
#include "gamepad_battery_full.h"
#include "gamepad_battery_wired.h"
#include "gamepad_touchpad.h"
#include "gamepad_button.h"
#include "gamepad_button_small.h"
#include "gamepad_axis.h"
#include "gamepad_axis_arrow.h"
#include "gamepad_button_background.h"

/* This is indexed by SDL_GamepadButton. */
static const struct
{
    int x;
    int y;
} button_positions[] = {
    { 412, 192 }, /* SDL_GAMEPAD_BUTTON_A */
    { 456, 157 }, /* SDL_GAMEPAD_BUTTON_B */
    { 367, 157 }, /* SDL_GAMEPAD_BUTTON_X */
    { 414, 126 }, /* SDL_GAMEPAD_BUTTON_Y */
    { 199, 157 }, /* SDL_GAMEPAD_BUTTON_BACK */
    { 257, 153 }, /* SDL_GAMEPAD_BUTTON_GUIDE */
    { 314, 157 }, /* SDL_GAMEPAD_BUTTON_START */
    { 100, 179 },  /* SDL_GAMEPAD_BUTTON_LEFT_STICK */
    { 330, 255 }, /* SDL_GAMEPAD_BUTTON_RIGHT_STICK */
    { 102, 65 },   /* SDL_GAMEPAD_BUTTON_LEFT_SHOULDER */
    { 421, 61 },  /* SDL_GAMEPAD_BUTTON_RIGHT_SHOULDER */
    { 179, 213 }, /* SDL_GAMEPAD_BUTTON_DPAD_UP */
    { 179, 274 }, /* SDL_GAMEPAD_BUTTON_DPAD_DOWN */
    { 141, 242 }, /* SDL_GAMEPAD_BUTTON_DPAD_LEFT */
    { 211, 242 }, /* SDL_GAMEPAD_BUTTON_DPAD_RIGHT */
    { 257, 199 }, /* SDL_GAMEPAD_BUTTON_MISC1 */
    { 157, 160 }, /* SDL_GAMEPAD_BUTTON_PADDLE1 */
    { 355, 160 }, /* SDL_GAMEPAD_BUTTON_PADDLE2 */
    { 157, 200 }, /* SDL_GAMEPAD_BUTTON_PADDLE3 */
    { 355, 200 }, /* SDL_GAMEPAD_BUTTON_PADDLE4 */
};

/* This is indexed by SDL_GamepadAxis. */
static const struct
{
    int x;
    int y;
    double angle;
} axis_positions[] = {
    { 99, 178, 270.0 },  /* LEFTX */
    { 99, 178, 0.0 },    /* LEFTY */
    { 331, 256, 270.0 }, /* RIGHTX */
    { 331, 256, 0.0 },   /* RIGHTY */
    { 116, 5, 0.0 },    /* TRIGGERLEFT */
    { 400, 5, 0.0 },   /* TRIGGERRIGHT */
};

static SDL_Rect touchpad_area = {
    148, 20, 216, 118
};

typedef struct
{
    Uint8 state;
    float x;
    float y;
    float pressure;
} GamepadTouchpadFinger;

struct GamepadImage
{
    SDL_Renderer *renderer;
    SDL_Texture *front_texture;
    SDL_Texture *back_texture;
    SDL_Texture *battery_texture[1 + SDL_JOYSTICK_POWER_MAX];
    SDL_Texture *touchpad_texture;
    SDL_Texture *button_texture;
    SDL_Texture *axis_texture;
    int gamepad_width;
    int gamepad_height;
    int battery_width;
    int battery_height;
    int touchpad_width;
    int touchpad_height;
    int button_width;
    int button_height;
    int axis_width;
    int axis_height;

    int x;
    int y;
    SDL_bool showing_front;
    SDL_bool showing_battery;
    SDL_bool showing_touchpad;

    SDL_bool buttons[SDL_GAMEPAD_BUTTON_MAX];
    int axes[SDL_GAMEPAD_AXIS_MAX];

    SDL_JoystickPowerLevel battery_level;

    int num_fingers;
    GamepadTouchpadFinger *fingers;
};

static SDL_Texture *CreateTexture(SDL_Renderer *renderer, unsigned char *data, unsigned int len)
{
    SDL_Texture *texture = NULL;
    SDL_Surface *surface;
    SDL_RWops *src = SDL_RWFromConstMem(data, len);
    if (src) {
        surface = SDL_LoadBMP_RW(src, SDL_TRUE);
        if (surface) {
            texture = SDL_CreateTextureFromSurface(renderer, surface);
            SDL_DestroySurface(surface);
        }
    }
    return texture;
}

GamepadImage *CreateGamepadImage(SDL_Renderer *renderer)
{
    GamepadImage *ctx = SDL_calloc(1, sizeof(*ctx));
    if (ctx) {
        ctx->renderer = renderer;
        ctx->front_texture = CreateTexture(renderer, gamepad_front_bmp, gamepad_front_bmp_len);
        ctx->back_texture = CreateTexture(renderer, gamepad_back_bmp, gamepad_back_bmp_len);
        SDL_QueryTexture(ctx->front_texture, NULL, NULL, &ctx->gamepad_width, &ctx->gamepad_height);

        ctx->battery_texture[1 + SDL_JOYSTICK_POWER_UNKNOWN] = CreateTexture(renderer, gamepad_battery_unknown_bmp, gamepad_battery_unknown_bmp_len);
        ctx->battery_texture[1 + SDL_JOYSTICK_POWER_EMPTY] = CreateTexture(renderer, gamepad_battery_empty_bmp, gamepad_battery_empty_bmp_len);
        ctx->battery_texture[1 + SDL_JOYSTICK_POWER_LOW] = CreateTexture(renderer, gamepad_battery_low_bmp, gamepad_battery_low_bmp_len);
        ctx->battery_texture[1 + SDL_JOYSTICK_POWER_MEDIUM] = CreateTexture(renderer, gamepad_battery_medium_bmp, gamepad_battery_medium_bmp_len);
        ctx->battery_texture[1 + SDL_JOYSTICK_POWER_FULL] = CreateTexture(renderer, gamepad_battery_full_bmp, gamepad_battery_full_bmp_len);
        ctx->battery_texture[1 + SDL_JOYSTICK_POWER_WIRED] = CreateTexture(renderer, gamepad_battery_wired_bmp, gamepad_battery_wired_bmp_len);
        SDL_QueryTexture(ctx->battery_texture[1 + SDL_JOYSTICK_POWER_UNKNOWN], NULL, NULL, &ctx->battery_width, &ctx->battery_height);

        ctx->touchpad_texture = CreateTexture(renderer, gamepad_touchpad_bmp, gamepad_touchpad_bmp_len);
        SDL_QueryTexture(ctx->touchpad_texture, NULL, NULL, &ctx->touchpad_width, &ctx->touchpad_height);

        ctx->button_texture = CreateTexture(renderer, gamepad_button_bmp, gamepad_button_bmp_len);
        SDL_QueryTexture(ctx->button_texture, NULL, NULL, &ctx->button_width, &ctx->button_height);
        SDL_SetTextureColorMod(ctx->button_texture, 10, 255, 21);

        ctx->axis_texture = CreateTexture(renderer, gamepad_axis_bmp, gamepad_axis_bmp_len);
        SDL_QueryTexture(ctx->axis_texture, NULL, NULL, &ctx->axis_width, &ctx->axis_height);
        SDL_SetTextureColorMod(ctx->axis_texture, 10, 255, 21);

        ctx->showing_front = SDL_TRUE;
    }
    return ctx;
}

void SetGamepadImagePosition(GamepadImage *ctx, int x, int y)
{
    if (!ctx) {
        return;
    }

    ctx->x = x;
    ctx->y = y;
}

void SetGamepadImageShowingFront(GamepadImage *ctx, SDL_bool showing_front)
{
    if (!ctx) {
        return;
    }

    ctx->showing_front = showing_front;
}

void SetGamepadImageShowingBattery(GamepadImage *ctx, SDL_bool showing_battery)
{
    if (!ctx) {
        return;
    }

    ctx->showing_battery = showing_battery;
}

void SetGamepadImageShowingTouchpad(GamepadImage *ctx, SDL_bool showing_touchpad)
{
    if (!ctx) {
        return;
    }

    ctx->showing_touchpad = showing_touchpad;
}

void GetGamepadImageArea(GamepadImage *ctx, int *x, int *y, int *width, int *height)
{
    if (!ctx) {
        if (x) {
            *x = 0;
        }
        if (y) {
            *y = 0;
        }
        if (width) {
            *width = 0;
        }
        if (height) {
            *height = 0;
        }
        return;
    }

    if (x) {
        *x = ctx->x;
    }
    if (y) {
        *y = ctx->y;
    }
    if (width) {
        *width = ctx->gamepad_width;
    }
    if (height) {
        *height = ctx->gamepad_height;
        if (ctx->showing_touchpad) {
            *height += ctx->touchpad_height;
        }
    }
}

int GetGamepadImageButtonWidth(GamepadImage *ctx)
{
    if (!ctx) {
        return 0;
    }

    return ctx->button_width;
}

int GetGamepadImageButtonHeight(GamepadImage *ctx)
{
    if (!ctx) {
        return 0;
    }

    return ctx->button_height;
}

int GetGamepadImageAxisWidth(GamepadImage *ctx)
{
    if (!ctx) {
        return 0;
    }

    return ctx->axis_width;
}

int GetGamepadImageAxisHeight(GamepadImage *ctx)
{
    if (!ctx) {
        return 0;
    }

    return ctx->axis_height;
}

SDL_GamepadButton GetGamepadImageButtonAt(GamepadImage *ctx, float x, float y)
{
    SDL_FPoint point;
    int i;

    if (!ctx) {
        return SDL_GAMEPAD_BUTTON_INVALID;
    }

    point.x = x;
    point.y = y;
    for (i = 0; i < SDL_arraysize(button_positions); ++i) {
        SDL_bool on_front = SDL_TRUE;

        if (i >= SDL_GAMEPAD_BUTTON_PADDLE1 && i <= SDL_GAMEPAD_BUTTON_PADDLE4) {
            on_front = SDL_FALSE;
        }
        if (on_front == ctx->showing_front) {
            SDL_FRect rect;
            rect.x = (float)ctx->x + button_positions[i].x - ctx->button_width / 2;
            rect.y = (float)ctx->y + button_positions[i].y - ctx->button_height / 2;
            rect.w = (float)ctx->button_width;
            rect.h = (float)ctx->button_height;
            if (SDL_PointInRectFloat(&point, &rect)) {
                return (SDL_GamepadButton)i;
            }
        }
    }
    return SDL_GAMEPAD_BUTTON_INVALID;
}

SDL_GamepadAxis GetGamepadImageAxisAt(GamepadImage *ctx, float x, float y)
{
    SDL_FPoint point;
    int i;

    if (!ctx) {
        return SDL_GAMEPAD_AXIS_INVALID;
    }

    point.x = x;
    point.y = y;
    if (ctx->showing_front) {
        for (i = 0; i < SDL_arraysize(axis_positions); ++i) {
            SDL_FRect rect;
            rect.x = (float)ctx->x + axis_positions[i].x - ctx->axis_width / 2;
            rect.y = (float)ctx->y + axis_positions[i].y - ctx->axis_height / 2;
            rect.w = (float)ctx->axis_width;
            rect.h = (float)ctx->axis_height;
            if (SDL_PointInRectFloat(&point, &rect)) {
                return (SDL_GamepadAxis)i;
            }
        }
    }
    return SDL_GAMEPAD_AXIS_INVALID;
}

void ClearGamepadImage(GamepadImage *ctx)
{
    if (!ctx) {
        return;
    }

    SDL_zeroa(ctx->buttons);
    SDL_zeroa(ctx->axes);
}

void SetGamepadImageButton(GamepadImage *ctx, SDL_GamepadButton button, SDL_bool active)
{
    if (!ctx) {
        return;
    }

    ctx->buttons[button] = active;
}

void SetGamepadImageAxis(GamepadImage *ctx, SDL_GamepadAxis axis, int direction)
{
    if (!ctx) {
        return;
    }

    ctx->axes[axis] = direction;
}

void UpdateGamepadImageFromGamepad(GamepadImage *ctx, SDL_Gamepad *gamepad)
{
    int i;

    if (!ctx) {
        return;
    }

    for (i = 0; i < SDL_GAMEPAD_BUTTON_TOUCHPAD; ++i) {
        const SDL_GamepadButton button = (SDL_GamepadButton)i;

        if (SDL_GetGamepadButton(gamepad, button) == SDL_PRESSED) {
            SetGamepadImageButton(ctx, button, SDL_TRUE);
        } else {
            SetGamepadImageButton(ctx, button, SDL_FALSE);
        }
    }

    for (i = 0; i < SDL_GAMEPAD_AXIS_MAX; ++i) {
        const SDL_GamepadAxis axis = (SDL_GamepadAxis)i;
        const Sint16 deadzone = 8000; /* !!! FIXME: real deadzone */
        const Sint16 value = SDL_GetGamepadAxis(gamepad, axis);
        if (value < -deadzone) {
            SetGamepadImageAxis(ctx, axis, -1);
        } else if (value > deadzone) {
            SetGamepadImageAxis(ctx, axis, 1);
        } else {
            SetGamepadImageAxis(ctx, axis, 0);
        }
    }

    ctx->battery_level = SDL_GetGamepadPowerLevel(gamepad);

    if (SDL_GetNumGamepadTouchpads(gamepad) > 0) {
        int num_fingers = SDL_GetNumGamepadTouchpadFingers(gamepad, 0);
        if (num_fingers != ctx->num_fingers) {
            GamepadTouchpadFinger *fingers = (GamepadTouchpadFinger *)SDL_realloc(ctx->fingers, num_fingers * sizeof(*fingers));
            if (fingers) {
                ctx->fingers = fingers;
                ctx->num_fingers = num_fingers;
            } else {
                num_fingers = SDL_min(ctx->num_fingers, num_fingers);
            }
        }
        for (i = 0; i < num_fingers; ++i) {
            GamepadTouchpadFinger *finger = &ctx->fingers[i];

            SDL_GetGamepadTouchpadFinger(gamepad, 0, i, &finger->state, &finger->x, &finger->y, &finger->pressure);
        }
    } else {
        if (ctx->fingers) {
            SDL_free(ctx->fingers);
            ctx->fingers = NULL;
            ctx->num_fingers = 0;
        }
    }
}

void RenderGamepadImage(GamepadImage *ctx)
{
    SDL_FRect dst;
    int i;

    if (!ctx) {
        return;
    }

    dst.x = (float)ctx->x;
    dst.y = (float)ctx->y;
    dst.w = (float)ctx->gamepad_width;
    dst.h = (float)ctx->gamepad_height;

    if (ctx->showing_front) {
        SDL_RenderTexture(ctx->renderer, ctx->front_texture, NULL, &dst);
    } else {
        SDL_RenderTexture(ctx->renderer, ctx->back_texture, NULL, &dst);
    }

    for (i = 0; i < SDL_arraysize(button_positions); ++i) {
        if (ctx->buttons[i]) {
            SDL_bool on_front = SDL_TRUE;

            if (i >= SDL_GAMEPAD_BUTTON_PADDLE1 && i <= SDL_GAMEPAD_BUTTON_PADDLE4) {
                on_front = SDL_FALSE;
            }
            if (on_front == ctx->showing_front) {
                dst.x = (float)ctx->x + button_positions[i].x - ctx->button_width / 2;
                dst.y = (float)ctx->y + button_positions[i].y - ctx->button_height / 2;
                dst.w = (float)ctx->button_width;
                dst.h = (float)ctx->button_height;
                SDL_RenderTexture(ctx->renderer, ctx->button_texture, NULL, &dst);
            }
        }
    }

    if (ctx->showing_front) {
        for (i = 0; i < SDL_arraysize(axis_positions); ++i) {
            if (ctx->axes[i] < 0) {
                const double angle = axis_positions[i].angle;
                dst.x = (float)ctx->x + axis_positions[i].x - ctx->axis_width / 2;
                dst.y = (float)ctx->y + axis_positions[i].y - ctx->axis_height / 2;
                dst.w = (float)ctx->axis_width;
                dst.h = (float)ctx->axis_height;
                SDL_RenderTextureRotated(ctx->renderer, ctx->axis_texture, NULL, &dst, angle, NULL, SDL_FLIP_NONE);
            } else if (ctx->axes[i] > 0) {
                const double angle = axis_positions[i].angle + 180.0;
                dst.x = (float)ctx->x + axis_positions[i].x - ctx->axis_width / 2;
                dst.y = (float)ctx->y + axis_positions[i].y - ctx->axis_height / 2;
                dst.w = (float)ctx->axis_width;
                dst.h = (float)ctx->axis_height;
                SDL_RenderTextureRotated(ctx->renderer, ctx->axis_texture, NULL, &dst, angle, NULL, SDL_FLIP_NONE);
            }
        }
    }

    if (ctx->showing_battery) {
        dst.x = (float)ctx->x + ctx->gamepad_width - ctx->battery_width;
        dst.y = (float)ctx->y;
        dst.w = (float)ctx->battery_width;
        dst.h = (float)ctx->battery_height;
        SDL_RenderTexture(ctx->renderer, ctx->battery_texture[1 + ctx->battery_level], NULL, &dst);
    }

    if (ctx->showing_touchpad) {
        dst.x = (float)ctx->x + (ctx->gamepad_width - ctx->touchpad_width) / 2;
        dst.y = (float)ctx->y + ctx->gamepad_height;
        dst.w = (float)ctx->touchpad_width;
        dst.h = (float)ctx->touchpad_height;
        SDL_RenderTexture(ctx->renderer, ctx->touchpad_texture, NULL, &dst);

        for (i = 0; i < ctx->num_fingers; ++i) {
            GamepadTouchpadFinger *finger = &ctx->fingers[i];

            if (finger->state) {
                dst.x = (float)ctx->x + (ctx->gamepad_width - ctx->touchpad_width) / 2;
                dst.x += touchpad_area.x + finger->x * touchpad_area.w;
                dst.x -= ctx->button_width / 2;
                dst.y = (float)ctx->y + ctx->gamepad_height;
                dst.y += touchpad_area.y + finger->y * touchpad_area.h;
                dst.y -= ctx->button_height / 2;
                dst.w = (float)ctx->button_width;
                dst.h = (float)ctx->button_height;
                SDL_SetTextureAlphaMod(ctx->button_texture, (Uint8)(finger->pressure * SDL_ALPHA_OPAQUE));
                SDL_RenderTexture(ctx->renderer, ctx->button_texture, NULL, &dst);
                SDL_SetTextureAlphaMod(ctx->button_texture, SDL_ALPHA_OPAQUE);
            }
        }
    }
}

void DestroyGamepadImage(GamepadImage *ctx)
{
    if (ctx) {
        int i;

        SDL_DestroyTexture(ctx->front_texture);
        SDL_DestroyTexture(ctx->back_texture);
        for (i = 0; i < SDL_arraysize(ctx->battery_texture); ++i) {
            SDL_DestroyTexture(ctx->battery_texture[i]);
        }
        SDL_DestroyTexture(ctx->touchpad_texture);
        SDL_DestroyTexture(ctx->button_texture);
        SDL_DestroyTexture(ctx->axis_texture);
        SDL_free(ctx);
    }
}


static const char *gamepad_button_names[] = {
    "A",
    "B",
    "X",
    "Y",
    "Back",
    "Guide",
    "Start",
    "Left Stick",
    "Right Stick",
    "Left Shoulder",
    "Right Shoulder",
    "DPAD Up",
    "DPAD Down",
    "DPAD Left",
    "DPAD Right",
    "Misc1",
    "Paddle1",
    "Paddle2",
    "Paddle3",
    "Paddle4",
    "Touchpad",
};
SDL_COMPILE_TIME_ASSERT(gamepad_button_names, SDL_arraysize(gamepad_button_names) == SDL_GAMEPAD_BUTTON_MAX);

static const char *gamepad_axis_names[] = {
    "LeftX",
    "RightX",
    "RightX",
    "RightY",
    "Left Trigger",
    "Right Trigger",
};
SDL_COMPILE_TIME_ASSERT(gamepad_axis_names, SDL_arraysize(gamepad_axis_names) == SDL_GAMEPAD_AXIS_MAX);

struct GamepadDisplay
{
    SDL_Renderer *renderer;
    SDL_Texture *button_texture;
    SDL_Texture *arrow_texture;
    int button_width;
    int button_height;
    int arrow_width;
    int arrow_height;

    float accel_data[3];
    float gyro_data[3];
    Uint64 last_sensor_update;

    SDL_Rect area;
};

GamepadDisplay *CreateGamepadDisplay(SDL_Renderer *renderer)
{
    GamepadDisplay *ctx = SDL_calloc(1, sizeof(*ctx));
    if (ctx) {
        ctx->renderer = renderer;

        ctx->button_texture = CreateTexture(renderer, gamepad_button_small_bmp, gamepad_button_small_bmp_len);
        SDL_QueryTexture(ctx->button_texture, NULL, NULL, &ctx->button_width, &ctx->button_height);

        ctx->arrow_texture = CreateTexture(renderer, gamepad_axis_arrow_bmp, gamepad_axis_arrow_bmp_len);
        SDL_QueryTexture(ctx->arrow_texture, NULL, NULL, &ctx->arrow_width, &ctx->arrow_height);
    }
    return ctx;
}

void SetGamepadDisplayArea(GamepadDisplay *ctx, int x, int y, int w, int h)
{
    if (!ctx) {
        return;
    }

    ctx->area.x = x;
    ctx->area.y = y;
    ctx->area.w = w;
    ctx->area.h = h;
}

static SDL_bool GetBindingString(const char *label, char *mapping, char *text, size_t size)
{
    char *key;
    char *value, *end;
    size_t length;

    *text = '\0';

    if (!mapping) {
        return SDL_FALSE;
    }

    key = SDL_strstr(mapping, label);
    if (key) {
        value = key + SDL_strlen(label);
        end = SDL_strchr(value, ',');
        if (end) {
            length = (end - value);
        } else {
            length = SDL_strlen(value);
        }
        if (length >= size) {
            length = size - 1;
        }
        SDL_memcpy(text, value, length);
        text[length] = '\0';
    }
    return *text ? SDL_TRUE : SDL_FALSE;
}

static SDL_bool GetButtonBindingString(SDL_GamepadButton button, char *mapping, char *text, size_t size)
{
    char label[32];

    SDL_snprintf(label, sizeof(label), "%s:", SDL_GetGamepadStringForButton(button));
    return GetBindingString(label, mapping, text, size);
}

static SDL_bool GetAxisBindingString(SDL_GamepadAxis axis, int direction, char *mapping, char *text, size_t size)
{
    char label[32];

    /* Check for explicit half-axis */
    if (direction < 0) {
        SDL_snprintf(label, sizeof(label), "-%s:", SDL_GetGamepadStringForAxis(axis));
    } else {
        SDL_snprintf(label, sizeof(label), "+%s:", SDL_GetGamepadStringForAxis(axis));
    }
    if (GetBindingString(label, mapping, text, size)) {
        return SDL_TRUE;
    }

    /* Get the binding for the whole axis and split it if necessary */
    SDL_snprintf(label, sizeof(label), "%s:", SDL_GetGamepadStringForAxis(axis));
    if (!GetBindingString(label, mapping, text, size)) {
        return SDL_FALSE;
    }
    if (axis != SDL_GAMEPAD_AXIS_LEFT_TRIGGER && axis != SDL_GAMEPAD_AXIS_RIGHT_TRIGGER) {
        if (*text == 'a') {
            /* Split the axis */
            size_t length = SDL_strlen(text) + 1;
            if ((length + 1) <= size) {
                SDL_memmove(text + 1, text, length);
                if (direction > 0) {
                    *text = '+';
                } else {
                    *text = '-';
                }
            }
        } else if (*text == '~') {
            /* Invert directions and split the axis */
            if (direction > 0) {
                *text = '-';
            } else {
                *text = '+';
            }
        }
    }
    return SDL_TRUE;
}

void RenderGamepadDisplay(GamepadDisplay *ctx, SDL_Gamepad *gamepad)
{
    float x, y;
    int i;
    char text[128], binding[32];
    const float margin = 8.0f;
    const float center = ctx->area.w / 2.0f;
    const float arrow_extent = 48.0f;
    SDL_FRect dst, rect;
    Uint8 r, g, b, a;
    char *mapping;
    SDL_bool has_accel;
    SDL_bool has_gyro;

    if (!ctx) {
        return;
    }

    SDL_GetRenderDrawColor(ctx->renderer, &r, &g, &b, &a);

    mapping = SDL_GetGamepadMapping(gamepad);

    x = ctx->area.x + margin;
    y = ctx->area.y + margin;

    for (i = 0; i < SDL_GAMEPAD_BUTTON_MAX; ++i) {
        SDL_GamepadButton button = (SDL_GamepadButton)i;

        SDL_snprintf(text, sizeof(text), "%s:", gamepad_button_names[i]);
        SDLTest_DrawString(ctx->renderer, x + center - SDL_strlen(text) * FONT_CHARACTER_SIZE, y, text);

        if (SDL_GetGamepadButton(gamepad, button)) {
            SDL_SetTextureColorMod(ctx->button_texture, 10, 255, 21);
        } else {
            SDL_SetTextureColorMod(ctx->button_texture, 255, 255, 255);
        }

        dst.x = x + center + 2.0f;
        dst.y = y + FONT_CHARACTER_SIZE / 2 - ctx->button_height / 2;
        dst.w = (float)ctx->button_width;
        dst.h = (float)ctx->button_height;
        SDL_RenderTexture(ctx->renderer, ctx->button_texture, NULL, &dst);

        if (GetButtonBindingString(button, mapping, binding, sizeof(binding))) {
            dst.x += dst.w + 2 * margin;
            SDLTest_DrawString(ctx->renderer, dst.x, y, binding);
        }

        y += ctx->button_height + 2.0f;
    }

    for (i = 0; i < SDL_GAMEPAD_AXIS_MAX; ++i) {
        SDL_GamepadAxis axis = (SDL_GamepadAxis)i;
        SDL_bool has_negative = (axis != SDL_GAMEPAD_AXIS_LEFT_TRIGGER && axis != SDL_GAMEPAD_AXIS_RIGHT_TRIGGER);
        Sint16 value = SDL_GetGamepadAxis(gamepad, axis);

        SDL_snprintf(text, sizeof(text), "%s:", gamepad_axis_names[i]);
        SDLTest_DrawString(ctx->renderer, x + center - SDL_strlen(text) * FONT_CHARACTER_SIZE, y, text);
        dst.x = x + center + 2.0f;
        dst.y = y + FONT_CHARACTER_SIZE / 2 - ctx->arrow_height / 2;
        dst.w = (float)ctx->arrow_width;
        dst.h = (float)ctx->arrow_height;

        if (has_negative) {
            if (value == SDL_MIN_SINT16) {
                SDL_SetTextureColorMod(ctx->arrow_texture, 10, 255, 21);
            } else {
                SDL_SetTextureColorMod(ctx->arrow_texture, 255, 255, 255);
            }
            SDL_RenderTextureRotated(ctx->renderer, ctx->arrow_texture, NULL, &dst, 0.0f, NULL, SDL_FLIP_HORIZONTAL);
        }

        dst.x += (float)ctx->arrow_width;

        SDL_SetRenderDrawColor(ctx->renderer, 200, 200, 200, SDL_ALPHA_OPAQUE);
        rect.x = dst.x + arrow_extent - 2.0f;
        rect.y = dst.y;
        rect.w = 4.0f;
        rect.h = (float)ctx->arrow_height;
        SDL_RenderFillRect(ctx->renderer, &rect);
        SDL_SetRenderDrawColor(ctx->renderer, r, g, b, a);

        if (value < 0) {
            SDL_SetRenderDrawColor(ctx->renderer, 8, 200, 16, SDL_ALPHA_OPAQUE);
            rect.w = ((float)value / SDL_MIN_SINT16) * arrow_extent;
            rect.x = dst.x + arrow_extent - rect.w;
            rect.y = dst.y + ctx->arrow_height * 0.25f;
            rect.h = ctx->arrow_height / 2.0f;
            SDL_RenderFillRect(ctx->renderer, &rect);
        }

        if (has_negative && GetAxisBindingString(axis, -1, mapping, binding, sizeof(binding))) {
            float text_x;

            SDL_SetRenderDrawColor(ctx->renderer, r, g, b, a);
            text_x = dst.x + arrow_extent / 2 - ((float)FONT_CHARACTER_SIZE * SDL_strlen(binding)) / 2;
            SDLTest_DrawString(ctx->renderer, text_x, y, binding);
        }

        dst.x += arrow_extent;

        if (value > 0) {
            SDL_SetRenderDrawColor(ctx->renderer, 8, 200, 16, SDL_ALPHA_OPAQUE);
            rect.w = ((float)value / SDL_MAX_SINT16) * arrow_extent;
            rect.x = dst.x;
            rect.y = dst.y + ctx->arrow_height * 0.25f;
            rect.h = ctx->arrow_height / 2.0f;
            SDL_RenderFillRect(ctx->renderer, &rect);
        }

        if (GetAxisBindingString(axis, 1, mapping, binding, sizeof(binding))) {
            float text_x;

            SDL_SetRenderDrawColor(ctx->renderer, r, g, b, a);
            text_x = dst.x + arrow_extent / 2 - ((float)FONT_CHARACTER_SIZE * SDL_strlen(binding)) / 2;
            SDLTest_DrawString(ctx->renderer, text_x, y, binding);
        }

        dst.x += arrow_extent;

        if (value == SDL_MAX_SINT16) {
            SDL_SetTextureColorMod(ctx->arrow_texture, 10, 255, 21);
        } else {
            SDL_SetTextureColorMod(ctx->arrow_texture, 255, 255, 255);
        }
        SDL_RenderTexture(ctx->renderer, ctx->arrow_texture, NULL, &dst);

        SDL_SetRenderDrawColor(ctx->renderer, r, g, b, a);

        y += ctx->button_height + 2;
    }

    if (SDL_GetNumGamepadTouchpads(gamepad) > 0) {
        int num_fingers = SDL_GetNumGamepadTouchpadFingers(gamepad, 0);
        for (i = 0; i < num_fingers; ++i) {
            Uint8 state;
            float finger_x, finger_y, finger_pressure;

            if (SDL_GetGamepadTouchpadFinger(gamepad, 0, i, &state, &finger_x, &finger_y, &finger_pressure) < 0) {
                continue;
            }

            SDL_snprintf(text, sizeof(text), "Touch finger %d:", i);
            SDLTest_DrawString(ctx->renderer, x + center - SDL_strlen(text) * FONT_CHARACTER_SIZE, y, text);

            if (state) {
                SDL_SetTextureColorMod(ctx->button_texture, 10, 255, 21);
            } else {
                SDL_SetTextureColorMod(ctx->button_texture, 255, 255, 255);
            }

            dst.x = x + center + 2.0f;
            dst.y = y + FONT_CHARACTER_SIZE / 2 - ctx->button_height / 2;
            dst.w = (float)ctx->button_width;
            dst.h = (float)ctx->button_height;
            SDL_RenderTexture(ctx->renderer, ctx->button_texture, NULL, &dst);

            if (state) {
                SDL_snprintf(text, sizeof(text), "(%.2f,%.2f)", finger_x, finger_y);
                SDLTest_DrawString(ctx->renderer, x + center + ctx->button_width + 4.0f, y, text);
            }

            y += ctx->button_height + 2.0f;
        }
    }

    has_accel = SDL_GamepadHasSensor(gamepad, SDL_SENSOR_ACCEL);
    has_gyro = SDL_GamepadHasSensor(gamepad, SDL_SENSOR_GYRO);
    if (has_accel || has_gyro) {
        const int SENSOR_UPDATE_INTERVAL_MS = 100;
        Uint64 now = SDL_GetTicks();

        if (now >= ctx->last_sensor_update + SENSOR_UPDATE_INTERVAL_MS) {
            if (has_accel) {
                SDL_GetGamepadSensorData(gamepad, SDL_SENSOR_ACCEL, ctx->accel_data, SDL_arraysize(ctx->accel_data));
            }
            if (has_gyro) {
                SDL_GetGamepadSensorData(gamepad, SDL_SENSOR_GYRO, ctx->gyro_data, SDL_arraysize(ctx->gyro_data));
            }
            ctx->last_sensor_update = now;
        }

        if (has_accel) {
            SDL_strlcpy(text, "Accelerometer:", sizeof(text));
            SDLTest_DrawString(ctx->renderer, x + center - SDL_strlen(text) * FONT_CHARACTER_SIZE, y, text);
            SDL_snprintf(text, sizeof(text), "(%.2f,%.2f,%.2f)", ctx->accel_data[0], ctx->accel_data[1], ctx->accel_data[2]);
            SDLTest_DrawString(ctx->renderer, x + center + 2.0f, y, text);

            y += ctx->button_height + 2.0f;
        }

        if (has_gyro) {
            SDL_strlcpy(text, "Gyro:", sizeof(text));
            SDLTest_DrawString(ctx->renderer, x + center - SDL_strlen(text) * FONT_CHARACTER_SIZE, y, text);
            SDL_snprintf(text, sizeof(text), "(%.2f,%.2f,%.2f)", ctx->gyro_data[0], ctx->gyro_data[1], ctx->gyro_data[2]);
            SDLTest_DrawString(ctx->renderer, x + center + 2.0f, y, text);

            y += ctx->button_height + 2.0f;
        }
    }

    SDL_free(mapping);
}

void DestroyGamepadDisplay(GamepadDisplay *ctx)
{
    if (!ctx) {
        return;
    }

    SDL_DestroyTexture(ctx->button_texture);
    SDL_DestroyTexture(ctx->arrow_texture);
    SDL_free(ctx);
}


struct JoystickDisplay
{
    SDL_Renderer *renderer;
    SDL_Texture *button_texture;
    SDL_Texture *arrow_texture;
    int button_width;
    int button_height;
    int arrow_width;
    int arrow_height;

    SDL_Rect area;
};

JoystickDisplay *CreateJoystickDisplay(SDL_Renderer *renderer)
{
    JoystickDisplay *ctx = SDL_calloc(1, sizeof(*ctx));
    if (ctx) {
        ctx->renderer = renderer;

        ctx->button_texture = CreateTexture(renderer, gamepad_button_small_bmp, gamepad_button_small_bmp_len);
        SDL_QueryTexture(ctx->button_texture, NULL, NULL, &ctx->button_width, &ctx->button_height);

        ctx->arrow_texture = CreateTexture(renderer, gamepad_axis_arrow_bmp, gamepad_axis_arrow_bmp_len);
        SDL_QueryTexture(ctx->arrow_texture, NULL, NULL, &ctx->arrow_width, &ctx->arrow_height);
    }
    return ctx;
}

void SetJoystickDisplayArea(JoystickDisplay *ctx, int x, int y, int w, int h)
{
    if (!ctx) {
        return;
    }

    ctx->area.x = x;
    ctx->area.y = y;
    ctx->area.w = w;
    ctx->area.h = h;
}

void RenderJoystickDisplay(JoystickDisplay *ctx, SDL_Joystick *joystick)
{
    float x, y;
    int i;
    int nbuttons = SDL_GetNumJoystickButtons(joystick);
    int naxes = SDL_GetNumJoystickAxes(joystick);
    int nhats = SDL_GetNumJoystickHats(joystick);
    char text[32];
    const float margin = 8.0f;
    const float center = 80.0f;
    const float arrow_extent = 48.0f;
    SDL_FRect dst, rect;
    Uint8 r, g, b, a;

    if (!ctx) {
        return;
    }

    SDL_GetRenderDrawColor(ctx->renderer, &r, &g, &b, &a);

    x = (float)ctx->area.x + margin;
    y = (float)ctx->area.y + margin;

    if (nbuttons > 0) {
        SDLTest_DrawString(ctx->renderer, x, y, "BUTTONS");
        y += FONT_LINE_HEIGHT + 2;

        for (i = 0; i < nbuttons; ++i) {
            SDL_snprintf(text, sizeof(text), "%2.d:", i);
            SDLTest_DrawString(ctx->renderer, x, y, text);

            if (SDL_GetJoystickButton(joystick, (Uint8)i)) {
                SDL_SetTextureColorMod(ctx->button_texture, 10, 255, 21);
            } else {
                SDL_SetTextureColorMod(ctx->button_texture, 255, 255, 255);
            }

            dst.x = x + FONT_CHARACTER_SIZE * SDL_strlen(text) + 2;
            dst.y = y + FONT_CHARACTER_SIZE / 2 - ctx->button_height / 2;
            dst.w = (float)ctx->button_width;
            dst.h = (float)ctx->button_height;
            SDL_RenderTexture(ctx->renderer, ctx->button_texture, NULL, &dst);

            y += ctx->button_height + 2;
        }
    }

    x = (float)ctx->area.x + margin + center + margin;
    y = (float)ctx->area.y + margin;

    if (naxes > 0) {
        SDLTest_DrawString(ctx->renderer, x, y, "AXES");
        y += FONT_LINE_HEIGHT + 2;

        for (i = 0; i < naxes; ++i) {
            Sint16 value = SDL_GetJoystickAxis(joystick, i);

            SDL_snprintf(text, sizeof(text), "%d:", i);
            SDLTest_DrawString(ctx->renderer, x, y, text);

            dst.x = x + FONT_CHARACTER_SIZE * SDL_strlen(text) + 2.0f;
            dst.y = y + FONT_CHARACTER_SIZE / 2 - ctx->arrow_height / 2;
            dst.w = (float)ctx->arrow_width;
            dst.h = (float)ctx->arrow_height;

            if (value == SDL_MIN_SINT16) {
                SDL_SetTextureColorMod(ctx->arrow_texture, 10, 255, 21);
            } else {
                SDL_SetTextureColorMod(ctx->arrow_texture, 255, 255, 255);
            }
            SDL_RenderTextureRotated(ctx->renderer, ctx->arrow_texture, NULL, &dst, 0.0f, NULL, SDL_FLIP_HORIZONTAL);

            dst.x += (float)ctx->arrow_width;

            SDL_SetRenderDrawColor(ctx->renderer, 200, 200, 200, SDL_ALPHA_OPAQUE);
            rect.x = dst.x + arrow_extent - 2.0f;
            rect.y = dst.y;
            rect.w = 4.0f;
            rect.h = (float)ctx->arrow_height;
            SDL_RenderFillRect(ctx->renderer, &rect);
            SDL_SetRenderDrawColor(ctx->renderer, r, g, b, a);

            if (value < 0) {
                SDL_SetRenderDrawColor(ctx->renderer, 8, 200, 16, SDL_ALPHA_OPAQUE);
                rect.w = ((float)value / SDL_MIN_SINT16) * arrow_extent;
                rect.x = dst.x + arrow_extent - rect.w;
                rect.y = dst.y + ctx->arrow_height * 0.25f;
                rect.h = ctx->arrow_height / 2.0f;
                SDL_RenderFillRect(ctx->renderer, &rect);
            }

            dst.x += arrow_extent;

            if (value > 0) {
                SDL_SetRenderDrawColor(ctx->renderer, 8, 200, 16, SDL_ALPHA_OPAQUE);
                rect.w = ((float)value / SDL_MAX_SINT16) * arrow_extent;
                rect.x = dst.x;
                rect.y = dst.y + ctx->arrow_height * 0.25f;
                rect.h = ctx->arrow_height / 2.0f;
                SDL_RenderFillRect(ctx->renderer, &rect);
            }

            dst.x += arrow_extent;

            if (value == SDL_MAX_SINT16) {
                SDL_SetTextureColorMod(ctx->arrow_texture, 10, 255, 21);
            } else {
                SDL_SetTextureColorMod(ctx->arrow_texture, 255, 255, 255);
            }
            SDL_RenderTexture(ctx->renderer, ctx->arrow_texture, NULL, &dst);

            SDL_SetRenderDrawColor(ctx->renderer, r, g, b, a);

            y += ctx->button_height + 2;
        }
    }

    y += FONT_LINE_HEIGHT + 2;

    if (nhats > 0) {
        SDLTest_DrawString(ctx->renderer, x, y, "HATS");
        y += FONT_LINE_HEIGHT + 2 + 1.5f * ctx->button_height - FONT_CHARACTER_SIZE / 2;

        for (i = 0; i < nhats; ++i) {
            Uint8 value = SDL_GetJoystickHat(joystick, i);

            SDL_snprintf(text, sizeof(text), "%d:", i);
            SDLTest_DrawString(ctx->renderer, x, y, text);

            if (value & SDL_HAT_LEFT) {
                SDL_SetTextureColorMod(ctx->button_texture, 10, 255, 21);
            } else {
                SDL_SetTextureColorMod(ctx->button_texture, 255, 255, 255);
            }

            dst.x = x + FONT_CHARACTER_SIZE * SDL_strlen(text) + 2;
            dst.y = y + FONT_CHARACTER_SIZE / 2 - ctx->button_height / 2;
            dst.w = (float)ctx->button_width;
            dst.h = (float)ctx->button_height;
            SDL_RenderTexture(ctx->renderer, ctx->button_texture, NULL, &dst);

            if (value & SDL_HAT_UP) {
                SDL_SetTextureColorMod(ctx->button_texture, 10, 255, 21);
            } else {
                SDL_SetTextureColorMod(ctx->button_texture, 255, 255, 255);
            }

            dst.x += (float)ctx->button_width;
            dst.y -= (float)ctx->button_height;
            SDL_RenderTexture(ctx->renderer, ctx->button_texture, NULL, &dst);

            if (value & SDL_HAT_DOWN) {
                SDL_SetTextureColorMod(ctx->button_texture, 10, 255, 21);
            } else {
                SDL_SetTextureColorMod(ctx->button_texture, 255, 255, 255);
            }

            dst.y += (float)ctx->button_height * 2;
            SDL_RenderTexture(ctx->renderer, ctx->button_texture, NULL, &dst);

            if (value & SDL_HAT_RIGHT) {
                SDL_SetTextureColorMod(ctx->button_texture, 10, 255, 21);
            } else {
                SDL_SetTextureColorMod(ctx->button_texture, 255, 255, 255);
            }

            dst.x += (float)ctx->button_width;
            dst.y = y + FONT_CHARACTER_SIZE / 2 - ctx->button_height / 2;
            SDL_RenderTexture(ctx->renderer, ctx->button_texture, NULL, &dst);

            y += 3 * ctx->button_height + 2;
        }
    }
}

void DestroyJoystickDisplay(JoystickDisplay *ctx)
{
    if (!ctx) {
        return;
    }

    SDL_DestroyTexture(ctx->button_texture);
    SDL_DestroyTexture(ctx->arrow_texture);
    SDL_free(ctx);
}


struct GamepadButton
{
    SDL_Renderer *renderer;
    SDL_Texture *background;
    int background_width;
    int background_height;

    SDL_FRect area;

    char *label;
    int label_width;
    int label_height;

    SDL_bool highlight;
};

GamepadButton *CreateGamepadButton(SDL_Renderer *renderer, const char *label)
{
    GamepadButton *ctx = SDL_calloc(1, sizeof(*ctx));
    if (ctx) {
        ctx->renderer = renderer;

        ctx->background = CreateTexture(renderer, gamepad_button_background_bmp, gamepad_button_background_bmp_len);
        SDL_QueryTexture(ctx->background, NULL, NULL, &ctx->background_width, &ctx->background_height);

        ctx->label = SDL_strdup(label);
        ctx->label_width = (int)(FONT_CHARACTER_SIZE * SDL_strlen(label));
        ctx->label_height = FONT_CHARACTER_SIZE;
    }
    return ctx;
}

void SetGamepadButtonArea(GamepadButton *ctx, int x, int y, int w, int h)
{
    if (!ctx) {
        return;
    }

    ctx->area.x = (float)x;
    ctx->area.y = (float)y;
    ctx->area.w = (float)w;
    ctx->area.h = (float)h;
}

void SetGamepadButtonHighlight(GamepadButton *ctx, SDL_bool highlight)
{
    if (!ctx) {
        return;
    }

    ctx->highlight = highlight;
}

int GetGamepadButtonLabelWidth(GamepadButton *ctx)
{
    if (!ctx) {
        return 0;
    }

    return ctx->label_width;
}

int GetGamepadButtonLabelHeight(GamepadButton *ctx)
{
    if (!ctx) {
        return 0;
    }

    return ctx->label_height;
}

SDL_bool GamepadButtonContains(GamepadButton *ctx, float x, float y)
{
    SDL_FPoint point;

    if (!ctx) {
        return SDL_FALSE;
    }

    point.x = x;
    point.y = y;
    return SDL_PointInRectFloat(&point, &ctx->area);
}

void RenderGamepadButton(GamepadButton *ctx)
{
    SDL_FRect src, dst;
    float one_third_src_width;
    float one_third_src_height;

    if (!ctx) {
        return;
    }

    one_third_src_width = (float)ctx->background_width / 3;
    one_third_src_height = (float)ctx->background_height / 3;

    if (ctx->highlight) {
        SDL_SetTextureColorMod(ctx->background, 10, 255, 21);
    } else {
        SDL_SetTextureColorMod(ctx->background, 255, 255, 255);
    }

    /* Top left */
    src.x = 0.0f;
    src.y = 0.0f;
    src.w = one_third_src_width;
    src.h = one_third_src_height;
    dst.x = ctx->area.x;
    dst.y = ctx->area.y;
    dst.w = src.w;
    dst.h = src.h;
    SDL_RenderTexture(ctx->renderer, ctx->background, &src, &dst);

    /* Bottom left */
    src.y = (float)ctx->background_height - src.h;
    dst.y = ctx->area.y + ctx->area.h - dst.h;
    SDL_RenderTexture(ctx->renderer, ctx->background, &src, &dst);

    /* Bottom right */
    src.x = (float)ctx->background_width - src.w;
    dst.x = ctx->area.x + ctx->area.w - dst.w;
    SDL_RenderTexture(ctx->renderer, ctx->background, &src, &dst);

    /* Top right */
    src.y = 0.0f;
    dst.y = ctx->area.y;
    SDL_RenderTexture(ctx->renderer, ctx->background, &src, &dst);

    /* Left */
    src.x = 0.0f;
    src.y = one_third_src_height;
    dst.x = ctx->area.x;
    dst.y = ctx->area.y + one_third_src_height;
    dst.w = one_third_src_width;
    dst.h = (float)ctx->area.h - 2 * one_third_src_height;
    SDL_RenderTexture(ctx->renderer, ctx->background, &src, &dst);

    /* Right */
    src.x = (float)ctx->background_width - one_third_src_width;
    dst.x = ctx->area.x + ctx->area.w - one_third_src_width;
    SDL_RenderTexture(ctx->renderer, ctx->background, &src, &dst);

    /* Top */
    src.x = one_third_src_width;
    src.y = 0.0f;
    dst.x = ctx->area.x + one_third_src_width;
    dst.y = ctx->area.y;
    dst.w = ctx->area.w - 2 * one_third_src_width;
    dst.h = one_third_src_height;
    SDL_RenderTexture(ctx->renderer, ctx->background, &src, &dst);

    /* Bottom */
    src.y = (float)ctx->background_height - src.h;
    dst.y = ctx->area.y + ctx->area.h - one_third_src_height;
    SDL_RenderTexture(ctx->renderer, ctx->background, &src, &dst);

    /* Center */
    src.x = one_third_src_width;
    src.y = one_third_src_height;
    dst.x = ctx->area.x + one_third_src_width;
    dst.y = ctx->area.y + one_third_src_height;
    dst.w = ctx->area.w - 2 * one_third_src_width;
    dst.h = (float)ctx->area.h - 2 * one_third_src_height;
    SDL_RenderTexture(ctx->renderer, ctx->background, &src, &dst);

    /* Label */
    dst.x = ctx->area.x + ctx->area.w / 2 - ctx->label_width / 2;
    dst.y = ctx->area.y + ctx->area.h / 2 - ctx->label_height / 2;
    SDLTest_DrawString(ctx->renderer, dst.x, dst.y, ctx->label);
}

void DestroyGamepadButton(GamepadButton *ctx)
{
    if (!ctx) {
        return;
    }

    SDL_DestroyTexture(ctx->background);
    SDL_free(ctx->label);
    SDL_free(ctx);
}