diff --git a/include/SDL_hints.h b/include/SDL_hints.h index d8d8075bd..0c772c457 100644 --- a/include/SDL_hints.h +++ b/include/SDL_hints.h @@ -314,6 +314,17 @@ extern "C" { */ #define SDL_HINT_MOUSE_RELATIVE_SPEED_SCALE "SDL_MOUSE_RELATIVE_SPEED_SCALE" +/** + * \brief A variable controlling whether relative mouse motion is affected by renderer scaling + * + * This variable can be set to the following values: + * "0" - Relative motion is unaffected by DPI or renderer's logical size + * "1" - Relative motion is scaled according to DPI scaling and logical size + * + * By default relative mouse deltas are affected by DPI and renderer scaling + */ +#define SDL_HINT_MOUSE_RELATIVE_SCALING "SDL_MOUSE_RELATIVE_SCALING" + /** * \brief A variable controlling whether relative mouse mode is implemented using mouse warping * diff --git a/src/render/SDL_render.c b/src/render/SDL_render.c index 0c4cfe95e..a3c5f36f7 100644 --- a/src/render/SDL_render.c +++ b/src/render/SDL_render.c @@ -660,13 +660,13 @@ SDL_RendererEventWatch(void *userdata, SDL_Event *event) event->motion.y -= (int)(viewport.y * renderer->dpi_scale.y); event->motion.x = (int)(event->motion.x / (scale.x * renderer->dpi_scale.x)); event->motion.y = (int)(event->motion.y / (scale.y * renderer->dpi_scale.y)); - if (event->motion.xrel != 0) { + if (event->motion.xrel != 0 && renderer->relative_scaling) { float rel = renderer->xrel + event->motion.xrel / (scale.x * renderer->dpi_scale.x); float trunc = SDL_truncf(rel); renderer->xrel = rel - trunc; event->motion.xrel = trunc; } - if (event->motion.yrel != 0) { + if (event->motion.yrel != 0 && renderer->relative_scaling) { float rel = renderer->yrel + event->motion.yrel / (scale.y * renderer->dpi_scale.y); float trunc = SDL_truncf(rel); renderer->yrel = rel - trunc; @@ -875,6 +875,8 @@ SDL_CreateRenderer(SDL_Window * window, int index, Uint32 flags) } } + renderer->relative_scaling = SDL_GetHintBoolean(SDL_HINT_MOUSE_RELATIVE_SCALING, SDL_TRUE); + if (SDL_GetWindowFlags(window) & (SDL_WINDOW_HIDDEN|SDL_WINDOW_MINIMIZED)) { renderer->hidden = SDL_TRUE; } else { diff --git a/src/render/SDL_sysrender.h b/src/render/SDL_sysrender.h index ee6f7312c..5bb98094e 100644 --- a/src/render/SDL_sysrender.h +++ b/src/render/SDL_sysrender.h @@ -189,6 +189,9 @@ struct SDL_Renderer /* The pixel to point coordinate scale */ SDL_FPoint dpi_scale; + /* Whether or not to scale relative mouse motion */ + SDL_bool relative_scaling; + /* Remainder from scaled relative motion */ float xrel; float yrel;