Support proper mode switching on RISC OS

src/video/riscos/SDL_riscosframebuffer.c

@@ -97,8 +97,8 @@ int RISCOS_UpdateWindowFramebuffer(_THIS, SDL_Window * window, const SDL_Rect *
     regs.r[0] = 512+52;
     regs.r[1] = (int)driverdata->fb_area;
     regs.r[2] = (int)driverdata->fb_sprite;
-    regs.r[3] = window->x << 1;
-    regs.r[4] = window->y << 1;
+    regs.r[3] = 0; /* window->x << 1; */
+    regs.r[4] = 0; /* window->y << 1; */
     regs.r[5] = 0x50;
     regs.r[6] = 0;
     regs.r[7] = 0;

src/video/riscos/SDL_riscosmodes.c

@@ -0,0 +1,255 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2021 Sam Lantinga <[email protected]>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "../../SDL_internal.h"
+
+#if SDL_VIDEO_DRIVER_RISCOS
+
+#include "../SDL_sysvideo.h"
+
+#include "SDL_riscosvideo.h"
+#include "SDL_riscosmodes.h"
+
+#include <kernel.h>
+#include <swis.h>
+
+enum {
+    MODE_FLAG_565 = 1 << 7,
+
+    MODE_FLAG_COLOUR_SPACE = 0xF << 12,
+
+    MODE_FLAG_TBGR = 0,
+    MODE_FLAG_TRGB = 1 << 14,
+    MODE_FLAG_ABGR = 1 << 15,
+    MODE_FLAG_ARGB = MODE_FLAG_TRGB | MODE_FLAG_ABGR
+};
+
+static const struct {
+    SDL_PixelFormatEnum pixel_format;
+    int modeflags, ncolour, log2bpp;
+} mode_to_pixelformat[] = {
+    /* { SDL_PIXELFORMAT_INDEX1LSB, 0, 1, 0 }, */
+    /* { SDL_PIXELFORMAT_INDEX2LSB, 0, 3, 1 }, */
+    /* { SDL_PIXELFORMAT_INDEX4LSB, 0, 15, 2 }, */
+    /* { SDL_PIXELFORMAT_INDEX8,    MODE_FLAG_565, 255, 3 }, */
+    { SDL_PIXELFORMAT_XBGR1555,  MODE_FLAG_TBGR, 65535, 4 },
+    { SDL_PIXELFORMAT_XRGB1555,  MODE_FLAG_TRGB, 65535, 4 },
+    { SDL_PIXELFORMAT_ABGR1555,  MODE_FLAG_ABGR, 65535, 4 },
+    { SDL_PIXELFORMAT_ARGB1555,  MODE_FLAG_ARGB, 65535, 4 },
+    { SDL_PIXELFORMAT_XBGR4444,  MODE_FLAG_TBGR, 4095, 4 },
+    { SDL_PIXELFORMAT_XRGB4444,  MODE_FLAG_TRGB, 4095, 4 },
+    { SDL_PIXELFORMAT_ABGR4444,  MODE_FLAG_ABGR, 4095, 4 },
+    { SDL_PIXELFORMAT_ARGB4444,  MODE_FLAG_ARGB, 4095, 4 },
+    { SDL_PIXELFORMAT_BGR565,    MODE_FLAG_TBGR | MODE_FLAG_565, 65535, 4 },
+    { SDL_PIXELFORMAT_RGB565,    MODE_FLAG_TRGB | MODE_FLAG_565, 65535, 4 },
+    { SDL_PIXELFORMAT_BGR24,     MODE_FLAG_TBGR, 16777215, 6 },
+    { SDL_PIXELFORMAT_RGB24,     MODE_FLAG_TRGB, 16777215, 6 },
+    { SDL_PIXELFORMAT_XBGR8888,  MODE_FLAG_TBGR, -1, 5 },
+    { SDL_PIXELFORMAT_XRGB8888,  MODE_FLAG_TRGB, -1, 5 },
+    { SDL_PIXELFORMAT_ABGR8888,  MODE_FLAG_ABGR, -1, 5 },
+    { SDL_PIXELFORMAT_ARGB8888,  MODE_FLAG_ARGB, -1, 5 }
+};
+
+static SDL_PixelFormatEnum
+RISCOS_ModeToPixelFormat(int ncolour, int modeflags, int log2bpp)
+{
+    int i;
+
+    for (i = 0; i < SDL_arraysize(mode_to_pixelformat); i++) {
+        if (log2bpp == mode_to_pixelformat[i].log2bpp &&
+           (ncolour == mode_to_pixelformat[i].ncolour || ncolour == 0) &&
+           (modeflags & (MODE_FLAG_565 | MODE_FLAG_COLOUR_SPACE)) == mode_to_pixelformat[i].modeflags) {
+            return mode_to_pixelformat[i].pixel_format;
+        }
+    }
+
+    return SDL_PIXELFORMAT_UNKNOWN;
+}
+
+static size_t
+measure_mode_block(const int *block)
+{
+    size_t blockSize = (block[0] == 2) ? 7 : 5;
+    while(block[blockSize] != -1) {
+        blockSize += 2;
+    }
+    blockSize++;
+
+    return blockSize * 4;
+}
+
+static int *
+read_mode_block(int *block, SDL_DisplayMode *mode)
+{
+    int xres, yres, ncolour, modeflags, log2bpp, rate;
+    int *end;
+
+    xres = block[1];
+    yres = block[2];
+    if ((block[0] & 0xFF) == 1) {
+        log2bpp = block[3];
+        rate = block[4];
+        end = block + 5;
+        ncolour = (1 << (1 << log2bpp)) - 1;
+        modeflags = MODE_FLAG_TBGR;
+    } else if ((block[0] & 0xFF) == 3) {
+        ncolour = block[3];
+        modeflags = block[4];
+        log2bpp = block[5];
+        rate = block[6];
+        end = block + 7;
+    } else {
+        return NULL;
+    }
+
+    mode->w = xres;
+    mode->h = yres;
+    mode->format = RISCOS_ModeToPixelFormat(ncolour, modeflags, log2bpp);
+    mode->refresh_rate = rate;
+
+    return end;
+}
+
+static void *
+copy_memory(const void *src, size_t size, size_t alloc)
+{
+    void *dst = SDL_malloc(alloc);
+    if (dst) {
+        SDL_memcpy(dst, src, size);
+    }
+    return dst;
+}
+
+int
+RISCOS_InitModes(_THIS)
+{
+    SDL_DisplayMode mode;
+    int *current_mode;
+    _kernel_swi_regs regs;
+    _kernel_oserror *error;
+    size_t size;
+
+    regs.r[0] = 1;
+    error = _kernel_swi(OS_ScreenMode, &regs, &regs);
+    if (error != NULL) {
+        return SDL_SetError("Unable to retrieve the current screen mode: %s (%i)", error->errmess, error->errnum);
+    }
+
+    current_mode = (int *)regs.r[1];
+    if (!read_mode_block(current_mode, &mode)) {
+        return SDL_SetError("Unsupported mode block format %d", current_mode[0]);
+    }
+
+    size = measure_mode_block(current_mode);
+    mode.driverdata = copy_memory(current_mode, size, size);
+    if (!mode.driverdata) {
+        return SDL_OutOfMemory();
+    }
+
+    return SDL_AddBasicVideoDisplay(&mode);
+}
+
+void
+RISCOS_GetDisplayModes(_THIS, SDL_VideoDisplay * display)
+{
+    SDL_DisplayMode mode;
+    _kernel_swi_regs regs;
+    _kernel_oserror *error;
+    void *block, *pos;
+
+    regs.r[0] = 2;
+    regs.r[2] = 0;
+    regs.r[6] = 0;
+    regs.r[7] = 0;
+    error = _kernel_swi(OS_ScreenMode, &regs, &regs);
+    if (error != NULL) {
+        SDL_SetError("Unable to enumerate screen modes: %s (%i)", error->errmess, error->errnum);
+        return;
+    }
+
+    block = SDL_malloc(-regs.r[7]);
+    if (!block) {
+        SDL_OutOfMemory();
+        return;
+    }
+
+    regs.r[6] = (int)block;
+    regs.r[7] = -regs.r[7];
+    error = _kernel_swi(OS_ScreenMode, &regs, &regs);
+    if (error != NULL) {
+        SDL_free(block);
+        SDL_SetError("Unable to enumerate screen modes: %s (%i)", error->errmess, error->errnum);
+        return;
+    }
+
+    for (pos = block; pos < (void *)regs.r[6]; pos += *((int *)pos)) {
+        size_t size;
+        void *end;
+
+        end = read_mode_block(pos + 4, &mode);
+        if (!end) {
+            continue;
+        }
+
+        if (mode.format == SDL_PIXELFORMAT_UNKNOWN)
+            continue;
+
+        size = (end - pos) - 4;
+        mode.driverdata = copy_memory(pos + 4, size, size + 4);
+        if (!mode.driverdata) {
+            SDL_OutOfMemory();
+            break;
+        }
+        *((int *)(mode.driverdata + size)) = -1;
+
+        if (!SDL_AddDisplayMode(display, &mode)) {
+            SDL_free(mode.driverdata);
+        }
+    }
+
+    SDL_free(block);
+}
+
+int
+RISCOS_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode)
+{
+    const char disable_cursor[] = { 23, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+    _kernel_swi_regs regs;
+    _kernel_oserror *error;
+    int i;
+
+    regs.r[0] = 0;
+    regs.r[1] = (int)mode->driverdata;
+    error = _kernel_swi(OS_ScreenMode, &regs, &regs);
+    if (error != NULL) {
+        return SDL_SetError("Unable to set the current screen mode: %s (%i)", error->errmess, error->errnum);
+    }
+
+    /* Turn the text cursor off */
+    for (i = 0; i < SDL_arraysize(disable_cursor); i++) {
+        _kernel_oswrch(disable_cursor[i]);
+    }
+
+    return 0;
+}
+
+#endif /* SDL_VIDEO_DRIVER_RISCOS */
+
+/* vi: set ts=4 sw=4 expandtab: */

src/video/riscos/SDL_riscosmodes.h

@@ -0,0 +1,33 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2021 Sam Lantinga <[email protected]>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "../../SDL_internal.h"
+
+#ifndef SDL_riscosmodes_h_
+#define SDL_riscosmodes_h_
+
+extern int RISCOS_InitModes(_THIS);
+extern void RISCOS_GetDisplayModes(_THIS, SDL_VideoDisplay * display);
+extern int RISCOS_SetDisplayMode(_THIS, SDL_VideoDisplay * display,
+                                 SDL_DisplayMode * mode);
+
+#endif /* SDL_riscosmodes_h_ */
+
+/* vi: set ts=4 sw=4 expandtab: */

src/video/riscos/SDL_riscosvideo.c

@@ -22,21 +22,6 @@
 
 #if SDL_VIDEO_DRIVER_RISCOS
 
-/* Dummy SDL video driver implementation; this is just enough to make an
- *  SDL-based application THINK it's got a working video driver, for
- *  applications that call SDL_Init(SDL_INIT_VIDEO) when they don't need it,
- *  and also for use as a collection of stubs when porting SDL to a new
- *  platform for which you haven't yet written a valid video driver.
- *
- * This is also a great way to determine bottlenecks: if you think that SDL
- *  is a performance problem for a given platform, enable this driver, and
- *  then see if your application runs faster without video overhead.
- *
- * Initial work by Ryan C. Gordon ([email protected]). A good portion
- *  of this was cut-and-pasted from Stephane Peter's work in the AAlib
- *  SDL video driver.  Renamed to "DUMMY" by Sam Lantinga.
- */
-
 #include "SDL_video.h"
 #include "SDL_mouse.h"
 #include "../SDL_sysvideo.h"
@@ -46,16 +31,13 @@
 #include "SDL_riscosvideo.h"
 #include "SDL_riscosevents_c.h"
 #include "SDL_riscosframebuffer_c.h"
+#include "SDL_riscosmodes.h"
 #include "SDL_riscoswindow.h"
 
-#include <kernel.h>
-#include <swis.h>
-
 #define RISCOSVID_DRIVER_NAME "riscos"
 
 /* Initialization/Query functions */
 static int RISCOS_VideoInit(_THIS);
-static int RISCOS_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode);
 static void RISCOS_VideoQuit(_THIS);
 
 /* RISC OS driver bootstrap functions */
@@ -81,9 +63,11 @@ RISCOS_CreateDevice(int devindex)
     /* Set the function pointers */
     device->VideoInit = RISCOS_VideoInit;
     device->VideoQuit = RISCOS_VideoQuit;
-    device->SetDisplayMode = RISCOS_SetDisplayMode;
     device->PumpEvents = RISCOS_PumpEvents;
 
+    device->GetDisplayModes = RISCOS_GetDisplayModes;
+    device->SetDisplayMode = RISCOS_SetDisplayMode;
+
     device->CreateSDLWindow = RISCOS_CreateWindow;
     device->DestroyWindow = RISCOS_DestroyWindow;
     device->GetWindowWMInfo = RISCOS_GetWindowWMInfo;
@@ -102,134 +86,18 @@ VideoBootStrap RISCOS_bootstrap = {
     RISCOS_CreateDevice
 };
 
-enum {
-    MODE_FLAG_565 = 1 << 7,
-
-    MODE_FLAG_COLOUR_SPACE = 0xF << 12,
-
-    MODE_FLAG_TBGR = 0,
-    MODE_FLAG_TRGB = 1 << 14,
-    MODE_FLAG_ABGR = 1 << 15,
-    MODE_FLAG_ARGB = MODE_FLAG_TRGB | MODE_FLAG_ABGR
-};
-
-#define MODE_350(type, xdpi, ydpi) \
-        (1 | (xdpi << 1) | (ydpi << 14) | (type << 27))
-#define MODE_521(type, xeig, yeig, flags) \
-        (0x78000001 | (xeig << 4) | (yeig << 6) | (flags & 0xFF00) | (type << 20))
-
-static const struct {
-    SDL_PixelFormatEnum pixel_format;
-    int modeflags, ncolour, log2bpp, sprite_type;
-} mode_to_pixelformat[] = {
-    { SDL_PIXELFORMAT_INDEX1LSB, 0, 1, 0, 1 },
-    /* { SDL_PIXELFORMAT_INDEX2LSB, 0, 3, 1, 2 }, */
-    { SDL_PIXELFORMAT_INDEX4LSB, 0, 15, 2, 3 },
-    { SDL_PIXELFORMAT_INDEX8,    MODE_FLAG_565, 255, 3, 4 },
-    { SDL_PIXELFORMAT_BGR555,    MODE_FLAG_TBGR, 65535, 4, 5 },
-    { SDL_PIXELFORMAT_RGB555,    MODE_FLAG_TRGB, 65535, 4, 5 },
-    { SDL_PIXELFORMAT_ABGR1555,  MODE_FLAG_ABGR, 65535, 4, 5 },
-    { SDL_PIXELFORMAT_ARGB1555,  MODE_FLAG_ARGB, 65535, 4, 5 },
-    { SDL_PIXELFORMAT_BGR444,    MODE_FLAG_TBGR, 4095, 4, 16 },
-    { SDL_PIXELFORMAT_RGB444,    MODE_FLAG_TRGB, 4095, 4, 16 },
-    { SDL_PIXELFORMAT_ABGR4444,  MODE_FLAG_ABGR, 4095, 4, 16 },
-    { SDL_PIXELFORMAT_ARGB4444,  MODE_FLAG_ARGB, 4095, 4, 16 },
-    { SDL_PIXELFORMAT_BGR565,    MODE_FLAG_TBGR | MODE_FLAG_565, 65535, 4, 10 },
-    { SDL_PIXELFORMAT_RGB565,    MODE_FLAG_TRGB | MODE_FLAG_565, 65535, 4, 10 },
-    { SDL_PIXELFORMAT_BGR24,     MODE_FLAG_TBGR, 16777215, 6, 8 },
-    { SDL_PIXELFORMAT_RGB24,     MODE_FLAG_TRGB, 16777215, 6, 8 },
-    { SDL_PIXELFORMAT_BGR888,    MODE_FLAG_TBGR, -1, 5, 6 },
-    { SDL_PIXELFORMAT_RGB888,    MODE_FLAG_TRGB, -1, 5, 6 },
-    { SDL_PIXELFORMAT_ABGR8888,  MODE_FLAG_ABGR, -1, 5, 6 },
-    { SDL_PIXELFORMAT_ARGB8888,  MODE_FLAG_ARGB, -1, 5, 6 }
-};
-
-static int ReadModeVariable(int mode, int variable) {
-    _kernel_swi_regs regs;
-    regs.r[0] = mode;
-    regs.r[1] = variable;
-    _kernel_swi(OS_ReadModeVariable, &regs, &regs);
-    return regs.r[2];
-}
-
-SDL_PixelFormatEnum RISCOS_ModeToPixelFormat(int *mode) {
-    int i, log2bpp, ncolour, modeflags;
-    log2bpp = ReadModeVariable((int)mode, 9);
-    ncolour = ReadModeVariable((int)mode, 3);
-    modeflags = ReadModeVariable((int)mode, 0);
-
-    for (i = 0; i < SDL_arraysize(mode_to_pixelformat); i++) {
-        if (log2bpp == mode_to_pixelformat[i].log2bpp &&
-           (ncolour == mode_to_pixelformat[i].ncolour || ncolour == 0) &&
-           (modeflags & (MODE_FLAG_565 | MODE_FLAG_COLOUR_SPACE)) == mode_to_pixelformat[i].modeflags) {
-            return mode_to_pixelformat[i].pixel_format;
-        }
-    }
-
-    return SDL_PIXELFORMAT_UNKNOWN;
-}
-
-static void *copy_mode_block(int *storeBlock)
-{
-    int *outBlock;
-    int blockSize = (storeBlock[0] == 2) ? 7 : 5;
-    while(storeBlock[blockSize] != -1) {
-        blockSize += 2;
-    }
-    blockSize++;
-
-    outBlock = SDL_calloc(sizeof(int), blockSize);
-    SDL_memcpy(outBlock, storeBlock, sizeof(int) * blockSize);
-    return outBlock;
-}
-
-int
+static int
 RISCOS_VideoInit(_THIS)
 {
-    SDL_DisplayMode mode;
-    int *current_mode;
-    _kernel_swi_regs regs;
-    _kernel_oserror *error;
-
-    regs.r[0] = 1;
-    error = _kernel_swi(OS_ScreenMode, &regs, &regs);
-    if (error != NULL) {
-        SDL_SetError("Unable to retrieve the current screen mode: %s (%i)", error->errmess, error->errnum);
+    if (RISCOS_InitModes(_this) < 0) {
         return -1;
     }
-    current_mode = (int *)regs.r[1];
-
-    /* Use a fake 32-bpp desktop mode */
-    mode.w = current_mode[1];
-    mode.h = current_mode[2];
-    if ((current_mode[0] & 0x7F) == 1) {
-        mode.format = RISCOS_ModeToPixelFormat(current_mode);
-        mode.refresh_rate = current_mode[4];
-    } else if ((current_mode[0] & 0x7F) == 3) {
-        mode.format = RISCOS_ModeToPixelFormat(current_mode);
-        mode.refresh_rate = current_mode[6];
-    } else {
-        return -1;
-    }
-    mode.driverdata = copy_mode_block(current_mode);
-
-    if (SDL_AddBasicVideoDisplay(&mode) < 0) {
-        return -1;
-    }
-
-    SDL_AddDisplayMode(&_this->displays[0], &mode);
 
     /* We're done! */
     return 0;
 }
 
-static int
-RISCOS_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode)
-{
-    return 0;
-}
-
-void
+static void
 RISCOS_VideoQuit(_THIS)
 {
 }

src/video/riscos/SDL_riscoswindow.c

@@ -40,6 +40,8 @@ RISCOS_CreateWindow(_THIS, SDL_Window * window)
     }
     driverdata->window = window;
 
+    window->flags |= SDL_WINDOW_FULLSCREEN;
+
     /* All done! */
     window->driverdata = driverdata;
     return 0;