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Fixed race condition where Android touch events could get scaled by a…
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… render target's viewport
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@slouken
slouken committed Jun 18, 2018
1 parent 9924a8e commit 74ec7ca
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Showing 2 changed files with 68 additions and 28 deletions.
94 changes: 66 additions & 28 deletions src/render/SDL_render.c
View file
Expand Up @@ -132,6 +132,16 @@ SDL_GetRenderDriverInfo(int index, SDL_RendererInfo * info)
#endif
}

static void GetWindowViewportValues(SDL_Renderer *renderer, int *logical_w, int *logical_h, SDL_Rect *viewport, SDL_FPoint *scale)
{
SDL_LockMutex(renderer->target_mutex);
*logical_w = renderer->target ? renderer->logical_w_backup : renderer->logical_w;
*logical_h = renderer->target ? renderer->logical_h_backup : renderer->logical_h;
*viewport = renderer->target ? renderer->viewport_backup : renderer->viewport;
*scale = renderer->target ? renderer->scale_backup : renderer->scale;
SDL_UnlockMutex(renderer->target_mutex);
}

static int SDLCALL
SDL_RendererEventWatch(void *userdata, SDL_Event *event)
{
Expand Down Expand Up @@ -197,54 +207,70 @@ SDL_RendererEventWatch(void *userdata, SDL_Event *event)
}
} else if (event->type == SDL_MOUSEMOTION) {
SDL_Window *window = SDL_GetWindowFromID(event->motion.windowID);
if (renderer->logical_w && window == renderer->window) {
event->motion.x -= (int)(renderer->viewport.x * renderer->dpi_scale.x);
event->motion.y -= (int)(renderer->viewport.y * renderer->dpi_scale.y);
event->motion.x = (int)(event->motion.x / (renderer->scale.x * renderer->dpi_scale.x));
event->motion.y = (int)(event->motion.y / (renderer->scale.y * renderer->dpi_scale.y));
if (event->motion.xrel > 0) {
event->motion.xrel = SDL_max(1, (int)(event->motion.xrel / (renderer->scale.x * renderer->dpi_scale.x)));
} else if (event->motion.xrel < 0) {
event->motion.xrel = SDL_min(-1, (int)(event->motion.xrel / (renderer->scale.x * renderer->dpi_scale.x)));
}
if (event->motion.yrel > 0) {
event->motion.yrel = SDL_max(1, (int)(event->motion.yrel / (renderer->scale.y * renderer->dpi_scale.y)));
} else if (event->motion.yrel < 0) {
event->motion.yrel = SDL_min(-1, (int)(event->motion.yrel / (renderer->scale.y * renderer->dpi_scale.y)));
if (window == renderer->window) {
int logical_w, logical_h;
SDL_Rect viewport;
SDL_FPoint scale;
GetWindowViewportValues(renderer, &logical_w, &logical_h, &viewport, &scale);
if (logical_w) {
event->motion.x -= (int)(viewport.x * renderer->dpi_scale.x);
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) {
event->motion.xrel = SDL_max(1, (int)(event->motion.xrel / (scale.x * renderer->dpi_scale.x)));
} else if (event->motion.xrel < 0) {
event->motion.xrel = SDL_min(-1, (int)(event->motion.xrel / (scale.x * renderer->dpi_scale.x)));
}
if (event->motion.yrel > 0) {
event->motion.yrel = SDL_max(1, (int)(event->motion.yrel / (scale.y * renderer->dpi_scale.y)));
} else if (event->motion.yrel < 0) {
event->motion.yrel = SDL_min(-1, (int)(event->motion.yrel / (scale.y * renderer->dpi_scale.y)));
}
}
}
} else if (event->type == SDL_MOUSEBUTTONDOWN ||
event->type == SDL_MOUSEBUTTONUP) {
SDL_Window *window = SDL_GetWindowFromID(event->button.windowID);
if (renderer->logical_w && window == renderer->window) {
event->button.x -= (int)(renderer->viewport.x * renderer->dpi_scale.x);
event->button.y -= (int)(renderer->viewport.y * renderer->dpi_scale.y);
event->button.x = (int)(event->button.x / (renderer->scale.x * renderer->dpi_scale.x));
event->button.y = (int)(event->button.y / (renderer->scale.y * renderer->dpi_scale.y));
if (window == renderer->window) {
int logical_w, logical_h;
SDL_Rect viewport;
SDL_FPoint scale;
GetWindowViewportValues(renderer, &logical_w, &logical_h, &viewport, &scale);
if (logical_w) {
event->button.x -= (int)(viewport.x * renderer->dpi_scale.x);
event->button.y -= (int)(viewport.y * renderer->dpi_scale.y);
event->button.x = (int)(event->button.x / (scale.x * renderer->dpi_scale.x));
event->button.y = (int)(event->button.y / (scale.y * renderer->dpi_scale.y));
}
}
} else if (event->type == SDL_FINGERDOWN ||
event->type == SDL_FINGERUP ||
event->type == SDL_FINGERMOTION) {
if (renderer->logical_w) {
int logical_w, logical_h;
SDL_Rect viewport;
SDL_FPoint scale;
GetWindowViewportValues(renderer, &logical_w, &logical_h, &viewport, &scale);
if (logical_w) {
int w = 1;
int h = 1;
SDL_GetRendererOutputSize(renderer, &w, &h);

event->tfinger.x *= (w - 1);
event->tfinger.y *= (h - 1);

event->tfinger.x -= (renderer->viewport.x * renderer->dpi_scale.x);
event->tfinger.y -= (renderer->viewport.y * renderer->dpi_scale.y);
event->tfinger.x = (event->tfinger.x / (renderer->scale.x * renderer->dpi_scale.x));
event->tfinger.y = (event->tfinger.y / (renderer->scale.y * renderer->dpi_scale.y));
event->tfinger.x -= (viewport.x * renderer->dpi_scale.x);
event->tfinger.y -= (viewport.y * renderer->dpi_scale.y);
event->tfinger.x = (event->tfinger.x / (scale.x * renderer->dpi_scale.x));
event->tfinger.y = (event->tfinger.y / (scale.y * renderer->dpi_scale.y));

if (renderer->logical_w > 1) {
event->tfinger.x = event->tfinger.x / (renderer->logical_w - 1);
if (logical_w > 1) {
event->tfinger.x = event->tfinger.x / (logical_w - 1);
} else {
event->tfinger.x = 0.5f;
}
if (renderer->logical_h > 1) {
event->tfinger.y = event->tfinger.y / (renderer->logical_h - 1);
if (logical_h > 1) {
event->tfinger.y = event->tfinger.y / (logical_h - 1);
} else {
event->tfinger.y = 0.5f;
}
Expand Down Expand Up @@ -345,6 +371,7 @@ SDL_CreateRenderer(SDL_Window * window, int index, Uint32 flags)
if (renderer) {
renderer->magic = &renderer_magic;
renderer->window = window;
renderer->target_mutex = SDL_CreateMutex();
renderer->scale.x = 1.0f;
renderer->scale.y = 1.0f;
renderer->dpi_scale.x = 1.0f;
Expand Down Expand Up @@ -392,6 +419,7 @@ SDL_CreateSoftwareRenderer(SDL_Surface * surface)

if (renderer) {
renderer->magic = &renderer_magic;
renderer->target_mutex = SDL_CreateMutex();
renderer->scale.x = 1.0f;
renderer->scale.y = 1.0f;

Expand Down Expand Up @@ -1203,6 +1231,8 @@ SDL_SetRenderTarget(SDL_Renderer *renderer, SDL_Texture *texture)
}
}

SDL_LockMutex(renderer->target_mutex);

if (texture && !renderer->target) {
/* Make a backup of the viewport */
renderer->viewport_backup = renderer->viewport;
Expand All @@ -1215,6 +1245,7 @@ SDL_SetRenderTarget(SDL_Renderer *renderer, SDL_Texture *texture)
renderer->target = texture;

if (renderer->SetRenderTarget(renderer, texture) < 0) {
SDL_UnlockMutex(renderer->target_mutex);
return -1;
}

Expand All @@ -1237,6 +1268,9 @@ SDL_SetRenderTarget(SDL_Renderer *renderer, SDL_Texture *texture)
renderer->logical_w = renderer->logical_w_backup;
renderer->logical_h = renderer->logical_h_backup;
}

SDL_UnlockMutex(renderer->target_mutex);

if (renderer->UpdateViewport(renderer) < 0) {
return -1;
}
Expand Down Expand Up @@ -2106,6 +2140,10 @@ SDL_DestroyRenderer(SDL_Renderer * renderer)
/* It's no longer magical... */
renderer->magic = NULL;

/* Free the target mutex */
SDL_DestroyMutex(renderer->target_mutex);
renderer->target_mutex = NULL;

/* Free the renderer instance */
renderer->DestroyRenderer(renderer);
}
Expand Down
2 changes: 2 additions & 0 deletions src/render/SDL_sysrender.h
View file
Expand Up @@ -25,6 +25,7 @@

#include "SDL_render.h"
#include "SDL_events.h"
#include "SDL_mutex.h"
#include "SDL_yuv_sw_c.h"

/* The SDL 2D rendering system */
Expand Down Expand Up @@ -172,6 +173,7 @@ struct SDL_Renderer
/* The list of textures */
SDL_Texture *textures;
SDL_Texture *target;
SDL_mutex *target_mutex;

Uint8 r, g, b, a; /**< Color for drawing operations values */
SDL_BlendMode blendMode; /**< The drawing blend mode */
Expand Down

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