From 44f299f49f60ba8985ac08eb997c823005099929 Mon Sep 17 00:00:00 2001
From: David Gow <[EMAIL REDACTED]>
Date: Thu, 3 Jun 2021 21:28:03 +0800
Subject: [PATCH] Add some common video modes to the modes list
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Some modern platforms (e.g. Wayland on KDE) don't expose any video modes
other than the current desktop resolution. For games which expect a
number of common VGA video modes to be available, this can result in
there either being no way to change resolution, or the game failing to
start due to a mode not being available.
Therefore, fake support for a number of common resolutions:
- 640×480
- 800×600
- 1024×768
- 1280×720
- 1920×1080
These are added to the mode list for all available pixel formats for
which there exists a valid, larger mode. The modes are included sorted
in the correct position within the mode list.
The SDL_VideoModeOK() function now uses the fake 1.2 modelist, so picks
up these modes.
If OpenGL Logical Scaling is explicitly disabled by the user, these
modes will not be added, as they may not function correctly if selected
(and the application uses OpenGL).
---
src/SDL12_compat.c | 119 +++++++++++++++++++++++++++++++++++----------
1 file changed, 92 insertions(+), 27 deletions(-)
diff --git a/src/SDL12_compat.c b/src/SDL12_compat.c
index 8cfc350..c36de9d 100644
--- a/src/SDL12_compat.c
+++ b/src/SDL12_compat.c
@@ -1439,6 +1439,58 @@ GetVideoDisplay(void)
}
}
+/* returns true if mode1 should sort before mode2 */
+static int
+VidModeSizeGreater(SDL12_Rect *mode1, SDL12_Rect *mode2)
+{
+ if (mode1->w > mode2->w) {
+ return 1;
+ } else if (mode2->w > mode1->w) {
+ return 0;
+ } else {
+ return (mode1->h > mode2->h);
+ }
+}
+
+static int
+AddVidModeToList(VideoModeList *vmode, SDL12_Rect *mode)
+{
+ void *ptr = NULL;
+ int i;
+
+ /* make sure we don't have this one already (with a different refresh rate, etc). */
+ for (i = 0; i < vmode->nummodes; i++) {
+ if ((vmode->modeslist12[i].w == mode->w) && (vmode->modeslist12[i].h == mode->h)) {
+ break;
+ }
+ }
+
+ if (i < vmode->nummodes) {
+ return 0; /* already have this one. */
+ }
+
+ ptr = SDL20_realloc(vmode->modeslist12, sizeof (SDL12_Rect) * (vmode->nummodes + 1));
+ if (ptr == NULL) {
+ return SDL20_OutOfMemory();
+ }
+ vmode->modeslist12 = (SDL12_Rect *) ptr;
+
+ vmode->modeslist12[vmode->nummodes] = *mode;
+
+ vmode->nummodes++;
+
+ return 0;
+}
+
+/* A list of fake video modes which are included. */
+static SDL12_Rect fake_modes[] = {
+ { 0, 0, 1920, 1080 },
+ { 0, 0, 1280, 720 },
+ { 0, 0, 1024, 768 },
+ { 0, 0, 800, 600 },
+ { 0, 0, 640, 480 }
+};
+
/* This sets up VideoModes and VideoModesCount. You end up with arrays by pixel
format, each with a value that 1.2's SDL_ListModes() can return. */
static int
@@ -1448,6 +1500,10 @@ Init12VidModes(void)
VideoModeList *vmode = NULL;
void *ptr = NULL;
int i, j;
+ SDL12_Rect prev_mode = { 0, 0, 0, 0 }, current_mode = { 0, 0, 0, 0 };
+ /* We only want to enable fake modes if OpenGL Logical Scaling is enabled. */
+ char *env = SDL20_getenv("SDL12COMPAT_OPENGL_SCALING");
+ SDL_bool use_fake_modes = (!env || SDL20_atoi(env)) ? SDL_TRUE : SDL_FALSE;
if (VideoModesCount > 0) {
return 0; /* already did this. */
@@ -1483,29 +1539,37 @@ Init12VidModes(void)
VideoModesCount++;
}
- /* make sure we don't have this one already (with a different refresh rate, etc). */
- for (j = 0; j < vmode->nummodes; j++) {
- if ((vmode->modeslist12[j].w == mode.w) && (vmode->modeslist12[j].h == mode.h)) {
- break;
- }
- }
+ current_mode.w = mode.w;
+ current_mode.h = mode.h;
- if (j < vmode->nummodes) {
- continue; /* already have this one. */
+ /* Attempt to add all of the fake modes. */
+ if (use_fake_modes) {
+ for (j = 0; j < sizeof(fake_modes) / sizeof(fake_modes[0]); ++j) {
+ if (VidModeSizeGreater(&prev_mode, &fake_modes[j]) && VidModeSizeGreater(&fake_modes[j], ¤t_mode)) {
+ if (AddVidModeToList(vmode, &fake_modes[j])) {
+ return SDL20_OutOfMemory();
+ }
+ }
+ }
}
- ptr = SDL20_realloc(vmode->modeslist12, sizeof (SDL12_Rect) * (vmode->nummodes + 1));
- if (ptr == NULL) {
+ if (AddVidModeToList(vmode, ¤t_mode)) {
return SDL20_OutOfMemory();
}
- vmode->modeslist12 = (SDL12_Rect *) ptr;
- vmode->modeslist12[vmode->nummodes].x = 0;
- vmode->modeslist12[vmode->nummodes].y = 0;
- vmode->modeslist12[vmode->nummodes].w = mode.w;
- vmode->modeslist12[vmode->nummodes].h = mode.h;
+ prev_mode.w = mode.w;
+ prev_mode.h = mode.h;
+ }
- vmode->nummodes++;
+ /* we need to try to add fake modes to the end of the list once there are no more real modes */
+ if (use_fake_modes) {
+ for (i = 0; i < sizeof(fake_modes) / sizeof(fake_modes[0]); ++i) {
+ if (VidModeSizeGreater(&prev_mode, &fake_modes[i])) {
+ if (AddVidModeToList(vmode, &fake_modes[i])) {
+ return SDL20_OutOfMemory();
+ }
+ }
+ }
}
/* link up modes12 for SDL_ListModes()'s use... */
@@ -3317,7 +3381,7 @@ SDL_GetVideoInfo(void)
DECLSPEC int SDLCALL
SDL_VideoModeOK(int width, int height, int bpp, Uint32 sdl12flags)
{
- int i, nummodes, actual_bpp = 0;
+ int i, j, actual_bpp = 0;
if (!SDL20_WasInit(SDL_INIT_VIDEO)) {
return 0;
@@ -3329,16 +3393,17 @@ SDL_VideoModeOK(int width, int height, int bpp, Uint32 sdl12flags)
return SDL_BITSPERPIXEL(mode.format);
}
- nummodes = SDL20_GetNumDisplayModes(VideoDisplayIndex);
- for (i = 0; i < nummodes; ++i) {
- SDL_DisplayMode mode;
- SDL20_GetDisplayMode(VideoDisplayIndex, i, &mode);
- if (!mode.w || !mode.h || (width == mode.w && height == mode.h)) {
- if (!mode.format) {
- return bpp;
- }
- if (SDL_BITSPERPIXEL(mode.format) >= (Uint32) bpp) {
- actual_bpp = SDL_BITSPERPIXEL(mode.format);
+ for (i = 0; i < VideoModesCount; ++i) {
+ VideoModeList *vmode = &VideoModes[i];
+ for (j = 0; j < vmode->nummodes; ++j) {
+ if (vmode->modeslist12[j].w == width && vmode->modeslist12[j].h == height)
+ {
+ if (!vmode->format) {
+ return bpp;
+ }
+ if (SDL_BITSPERPIXEL(vmode->format) >= (Uint32) bpp) {
+ actual_bpp = SDL_BITSPERPIXEL(vmode->format);
+ }
}
}
}