mirrors/SDL
1
0
Fork 0
mirror of https://github.com/libsdl-org/SDL.git synced 2025-10-05 01:16:26 +00:00
Code Issues Packages Projects Releases Wiki Activity

Added a hint SDL_HINT_MOUSE_RELATIVE_SYSTEM_SCALE to control whether to use system mouse acceleration on raw relative motion.

Browse Source 
This is currently only implemented on Windows, and "Enhanced pointer
precision" mode is not quite correct.
This commit is contained in:
Sam Lantinga
2022-08-22 16:25:25 -07:00
parent 3ce3594e38
commit 92b3c53c92
6 changed files with 249 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

125
src/events/SDL_mouse.c
View File

@@ -83,8 +83,10 @@ SDL_MouseNormalSpeedScaleChanged(void *userdata, const char *name, const char *o
SDL_Mouse *mouse = (SDL_Mouse *)userdata;
if (hint && *hint) {
mouse->enable_normal_speed_scale = SDL_TRUE;
mouse->normal_speed_scale = (float)SDL_atof(hint);
} else {
mouse->enable_normal_speed_scale = SDL_FALSE;
mouse->normal_speed_scale = 1.0f;
}
}
@@ -95,12 +97,22 @@ SDL_MouseRelativeSpeedScaleChanged(void *userdata, const char *name, const char
SDL_Mouse *mouse = (SDL_Mouse *)userdata;
if (hint && *hint) {
mouse->enable_relative_speed_scale = SDL_TRUE;
mouse->relative_speed_scale = (float)SDL_atof(hint);
} else {
mouse->enable_relative_speed_scale = SDL_FALSE;
mouse->relative_speed_scale = 1.0f;
}
}
static void SDLCALL
SDL_MouseRelativeSystemScaleChanged(void *userdata, const char *name, const char *oldValue, const char *hint)
{
SDL_Mouse *mouse = (SDL_Mouse *)userdata;
mouse->enable_relative_system_scale = SDL_GetStringBoolean(hint, SDL_FALSE);
}
static void SDLCALL
SDL_TouchMouseEventsChanged(void *userdata, const char *name, const char *oldValue, const char *hint)
{
@@ -189,6 +201,9 @@ SDL_MouseInit(void)
SDL_AddHintCallback(SDL_HINT_MOUSE_RELATIVE_SPEED_SCALE,
SDL_MouseRelativeSpeedScaleChanged, mouse);
SDL_AddHintCallback(SDL_HINT_MOUSE_RELATIVE_SYSTEM_SCALE,
SDL_MouseRelativeSystemScaleChanged, mouse);
SDL_AddHintCallback(SDL_HINT_TOUCH_MOUSE_EVENTS,
SDL_TouchMouseEventsChanged, mouse);
@@ -344,7 +359,10 @@ SDL_SendMouseMotion(SDL_Window * window, SDL_MouseID mouseID, int relative, int
static int
GetScaledMouseDelta(float scale, int value, float *accum)
{
if (scale != 1.0f) {
if (value && scale != 1.0f) {
if ((value > 0) != (*accum > 0)) {
*accum = 0.0f;
}
*accum += scale * value;
if (*accum >= 0.0f) {
value = (int)SDL_floor(*accum);
@@ -356,6 +374,100 @@ GetScaledMouseDelta(float scale, int value, float *accum)
return value;
}
static float
CalculateSystemScale(SDL_Mouse *mouse, int *x, int *y)
{
int i;
int n = mouse->num_system_scale_values;
float *v = mouse->system_scale_values;
float speed, coef, scale;
/* If we're using a single scale value, return that */
if (n == 1) {
return v[0];
}
speed = SDL_sqrtf((float)(*x * *x) + (*y * *y));
for (i = 0; i < (n - 2); i += 2) {
if (speed < v[i + 2]) {
break;
}
}
if (i == (n - 2)) {
scale = v[n - 1];
} else if (speed <= v[i]) {
scale = v[i + 1];
} else {
coef = (speed - v[i]) / (v[i + 2] - v[i]);
scale = v[i + 1] + (coef * (v[i + 3] - v[i + 1]));
}
SDL_Log("speed = %.2f, scale = %.2f\n", speed, scale);
return scale;
}
/* You can set either a single scale, or a set of {speed, scale} values in ascending order */
int
SDL_SetMouseSystemScale(int num_values, const float *values)
{
SDL_Mouse *mouse = SDL_GetMouse();
float *v;
if (num_values == mouse->num_system_scale_values &&
SDL_memcmp(values, mouse->system_scale_values, num_values * sizeof(*values)) == 0) {
/* Nothing has changed */
return 0;
}
if (num_values < 1) {
return SDL_SetError("You must have at least one scale value");
}
if (num_values > 1) {
/* Validate the values */
int i;
if (num_values < 4 || (num_values % 2) != 0) {
return SDL_SetError("You must pass a set of {speed, scale} values");
}
for (i = 0; i < (num_values - 2); i += 2) {
if (values[i] >= values[i + 2]) {
return SDL_SetError("Speed values must be in ascending order");
}
}
}
v = (float *)SDL_realloc(mouse->system_scale_values, num_values * sizeof(*values));
if (!v) {
return SDL_OutOfMemory();
}
SDL_memcpy(v, values, num_values * sizeof(*values));
mouse->num_system_scale_values = num_values;
mouse->system_scale_values = v;
return 0;
}
static void
GetScaledMouseDeltas(SDL_Mouse *mouse, int *x, int *y)
{
if (mouse->relative_mode) {
if (mouse->enable_relative_speed_scale) {
*x = GetScaledMouseDelta(mouse->relative_speed_scale, *x, &mouse->scale_accum_x);
*y = GetScaledMouseDelta(mouse->relative_speed_scale, *y, &mouse->scale_accum_y);
} else if (mouse->enable_relative_system_scale && mouse->num_system_scale_values > 0) {
float relative_system_scale = CalculateSystemScale(mouse, x, y);
*x = GetScaledMouseDelta(relative_system_scale, *x, &mouse->scale_accum_x);
*y = GetScaledMouseDelta(relative_system_scale, *y, &mouse->scale_accum_y);
}
} else {
if (mouse->enable_normal_speed_scale) {
*x = GetScaledMouseDelta(mouse->normal_speed_scale, *x, &mouse->scale_accum_x);
*y = GetScaledMouseDelta(mouse->normal_speed_scale, *y, &mouse->scale_accum_y);
}
}
}
static int
SDL_PrivateSendMouseMotion(SDL_Window * window, SDL_MouseID mouseID, int relative, int x, int y)
{
@@ -405,13 +517,7 @@ SDL_PrivateSendMouseMotion(SDL_Window * window, SDL_MouseID mouseID, int relativ
}
if (relative) {
if (mouse->relative_mode) {
x = GetScaledMouseDelta(mouse->relative_speed_scale, x, &mouse->scale_accum_x);
y = GetScaledMouseDelta(mouse->relative_speed_scale, y, &mouse->scale_accum_y);
} else {
x = GetScaledMouseDelta(mouse->normal_speed_scale, x, &mouse->scale_accum_x);
y = GetScaledMouseDelta(mouse->normal_speed_scale, y, &mouse->scale_accum_y);
}
GetScaledMouseDeltas(mouse, &x, &y);
xrel = x;
yrel = y;
x = (mouse->last_x + xrel);
@@ -818,6 +924,9 @@ SDL_MouseQuit(void)
SDL_DelHintCallback(SDL_HINT_MOUSE_RELATIVE_SPEED_SCALE,
SDL_MouseRelativeSpeedScaleChanged, mouse);
SDL_DelHintCallback(SDL_HINT_MOUSE_RELATIVE_SYSTEM_SCALE,
SDL_MouseRelativeSystemScaleChanged, mouse);
SDL_DelHintCallback(SDL_HINT_TOUCH_MOUSE_EVENTS,
SDL_TouchMouseEventsChanged, mouse);