encounter
/
SDL
mirror of https://github.com/encounter/SDL.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Visualise scroll wheel events in testmouse

This commit is contained in:
Christoph Reichenbach 2022-04-02 21:28:56 +00:00 committed by Sam Lantinga
parent 57118fb7de
commit 6cd444f0fa
1 changed files with 34 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
test/testmouse.c
View File

@ -39,6 +39,11 @@ static Line *active = NULL;
static Line *lines = NULL;
static int buttons = 0;
static SDL_bool wheel_x_active = SDL_FALSE;
static SDL_bool wheel_y_active = SDL_FALSE;
static float wheel_x = SCREEN_WIDTH * 0.5f;
static float wheel_y = SCREEN_HEIGHT * 0.5f;
static SDL_bool done = SDL_FALSE;
void
@ -81,6 +86,25 @@ loop(void *arg)
/* Check for events */
while (SDL_PollEvent(&event)) {
switch (event.type) {
case SDL_MOUSEWHEEL:
if (event.wheel.direction == SDL_MOUSEWHEEL_FLIPPED) {
event.wheel.preciseX *= -1.0f;
event.wheel.preciseY *= -1.0f;
event.wheel.x *= -1;
event.wheel.y *= -1;
}
if (event.wheel.preciseX != 0.0f) {
wheel_x_active = SDL_TRUE;
/* "positive to the right and negative to the left" */
wheel_x += event.wheel.preciseX * 10.0f;
}
if (event.wheel.preciseY != 0.0f) {
wheel_y_active = SDL_TRUE;
/* "positive away from the user and negative towards the user" */
wheel_y -= event.wheel.preciseY * 10.0f;
}
break;
case SDL_MOUSEMOTION:
if (!active)
break;
@ -134,6 +158,16 @@ loop(void *arg)
SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
SDL_RenderClear(renderer);
/* Mouse wheel */
SDL_SetRenderDrawColor(renderer, 0, 255, 128, 255);
if (wheel_x_active) {
SDL_RenderDrawLine(renderer, wheel_x, 0, wheel_x, SCREEN_HEIGHT);
}
if (wheel_y_active) {
SDL_RenderDrawLine(renderer, 0, wheel_y, SCREEN_WIDTH, wheel_y);
}
/* Lines from mouse clicks */
DrawLines(renderer);
if (active)
DrawLine(renderer, active);