Implement keyboard input on RISC OS

Partially based on a patch from http://www.riscos.info/websvn/listing.php?repname=gccsdk&path=%2Ftrunk%2Fautobuilder%2Flibraries%2Fsdl%2Flibsdl2%2F&rev=7174#a6401c766f408f1ea356e6977894cc6a5
Currently lacks support for mapping scancodes to keycodes.

src/video/riscos/SDL_riscosevents.c

@@ -22,18 +22,118 @@
 
 #if SDL_VIDEO_DRIVER_RISCOS
 
-/* Being a null driver, there's no event stream. We just define stubs for
-   most of the API. */
-
 #include "../../events/SDL_events_c.h"
 
+#include "SDL_log.h"
 #include "SDL_riscosvideo.h"
 #include "SDL_riscosevents_c.h"
+#include "scancodes_riscos.h"
+
+#include <kernel.h>
+
+static SDL_Scancode
+SDL_RISCOS_translate_keycode(int keycode)
+{
+    SDL_Scancode scancode = SDL_SCANCODE_UNKNOWN;
+
+    if (keycode < SDL_arraysize(riscos_scancode_table)) {
+        scancode = riscos_scancode_table[keycode];
+
+        if (scancode == SDL_SCANCODE_UNKNOWN) {
+            SDL_Log("The key you just pressed is not recognized by SDL: %d", keycode);
+        }
+    }
+
+    return scancode;
+}
+
+void
+RISCOS_PollKeyboard(_THIS)
+{
+    SDL_VideoData *driverdata = (SDL_VideoData *)_this->driverdata;
+    Uint8 key = 2;
+    int i;
+
+    /* Check for key releases */
+    for (i = 0; i < RISCOS_MAX_KEYS_PRESSED; i++) {
+        if (driverdata->key_pressed[i] != 255) {
+            if ((_kernel_osbyte(129, driverdata->key_pressed[i] ^ 0xff, 0xff) & 0xff) != 255) {
+                SDL_SendKeyboardKey(SDL_RELEASED, SDL_RISCOS_translate_keycode(driverdata->key_pressed[i]));
+                driverdata->key_pressed[i] = 255;
+            }
+        }
+    }
+
+    /* Check for key presses */
+    while (key < 0xff) {
+        SDL_bool already_pressed = SDL_FALSE;
+        key = _kernel_osbyte(121, key + 1, 0) & 0xff;
+        switch (key) {
+        case 255:
+        /* Ignore mouse keys */
+        case 9:
+        case 10:
+        case 11:
+        /* Ignore keys with multiple INKEY codes */
+        case 24:
+        case 40:
+        case 71:
+        case 87:
+            break;
+
+        default:
+            /* Do we already know of this key? */
+            for (i = 0; i < RISCOS_MAX_KEYS_PRESSED; i++) {
+                if (driverdata->key_pressed[i] == key) {
+                    already_pressed = SDL_TRUE;
+                    break;
+                }
+            }
+
+            if (!already_pressed) {
+                SDL_SendKeyboardKey(SDL_PRESSED, SDL_RISCOS_translate_keycode(key));
+                /* Record the press so we can detect release later. */
+                for (i = 0; i < RISCOS_MAX_KEYS_PRESSED; i++) {
+                    if (driverdata->key_pressed[i] == 255) {
+                        driverdata->key_pressed[i] = key;
+                        break;
+                    }
+                }
+            }
+        }
+    }
+}
+
+int
+RISCOS_InitEvents(_THIS)
+{
+    SDL_VideoData *driverdata = (SDL_VideoData *) _this->driverdata;
+    int i, status;
+
+    for (i = 0; i < RISCOS_MAX_KEYS_PRESSED; i++)
+        driverdata->key_pressed[i] = 255;
+
+    status = (_kernel_osbyte(202, 0, 255) & 0xFF);
+    SDL_ToggleModState(KMOD_NUM,  (status & (1 << 2)) == 0);
+    SDL_ToggleModState(KMOD_CAPS, (status & (1 << 4)) == 0);
+
+    /* Disable escape. */
+    _kernel_osbyte(229, 1, 0);
+
+    return 0;
+}
 
 void
 RISCOS_PumpEvents(_THIS)
 {
-    /* do nothing. */
+    RISCOS_PollKeyboard(_this);
+}
+
+void
+RISCOS_QuitEvents(_THIS)
+{
+    /* Re-enable escape. */
+    _kernel_osbyte(229, 0, 0);
 }
 
 #endif /* SDL_VIDEO_DRIVER_RISCOS */

src/video/riscos/SDL_riscosevents_c.h

@@ -26,7 +26,9 @@
 
 #include "SDL_riscosvideo.h"
 
+extern int RISCOS_InitEvents(_THIS);
 extern void RISCOS_PumpEvents(_THIS);
+extern void RISCOS_QuitEvents(_THIS);
 
 #endif /* SDL_riscosevents_c_h_ */
 

src/video/riscos/SDL_riscosvideo.c

@@ -45,6 +45,7 @@ static void RISCOS_VideoQuit(_THIS);
 static void
 RISCOS_DeleteDevice(SDL_VideoDevice * device)
 {
+    SDL_free(device->driverdata);
     SDL_free(device);
 }
 
@@ -52,6 +53,7 @@ static SDL_VideoDevice *
 RISCOS_CreateDevice(int devindex)
 {
     SDL_VideoDevice *device;
+    SDL_VideoData *phdata;
 
     /* Initialize all variables that we clean on shutdown */
     device = (SDL_VideoDevice *) SDL_calloc(1, sizeof(SDL_VideoDevice));
@@ -60,6 +62,16 @@ RISCOS_CreateDevice(int devindex)
         return (0);
     }
 
+    /* Initialize internal data */
+    phdata = (SDL_VideoData *) SDL_calloc(1, sizeof(SDL_VideoData));
+    if (phdata == NULL) {
+        SDL_OutOfMemory();
+        SDL_free(device);
+        return NULL;
+    }
+
+    device->driverdata = phdata;
+
     /* Set the function pointers */
     device->VideoInit = RISCOS_VideoInit;
     device->VideoQuit = RISCOS_VideoQuit;
@@ -89,6 +101,10 @@ VideoBootStrap RISCOS_bootstrap = {
 static int
 RISCOS_VideoInit(_THIS)
 {
+    if (RISCOS_InitEvents(_this) < 0) {
+        return -1;
+    }
+
     if (RISCOS_InitModes(_this) < 0) {
         return -1;
     }
@@ -100,6 +116,7 @@ RISCOS_VideoInit(_THIS)
 static void
 RISCOS_VideoQuit(_THIS)
 {
+    RISCOS_QuitEvents(_this);
 }
 
 #endif /* SDL_VIDEO_DRIVER_RISCOS */

src/video/riscos/SDL_riscosvideo.h

@@ -25,6 +25,13 @@
 
 #include "../SDL_sysvideo.h"
 
+#define RISCOS_MAX_KEYS_PRESSED 6
+
+typedef struct SDL_VideoData
+{
+    Uint8 key_pressed[RISCOS_MAX_KEYS_PRESSED];
+} SDL_VideoData;
+
 #endif /* SDL_riscosvideo_h_ */
 
 /* vi: set ts=4 sw=4 expandtab: */

src/video/riscos/scancodes_riscos.h

@@ -0,0 +1,158 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2021 Sam Lantinga <slouken@libsdl.org>
+
+  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_scancode.h"
+
+/* RISC OS key code to SDL_Keycode mapping table
+   Sources:
+   - https://www.riscosopen.org/wiki/documentation/show/Keyboard Scan Codes
+*/
+/* *INDENT-OFF* */
+static SDL_Scancode const riscos_scancode_table[] = {
+     /*   0 */   SDL_SCANCODE_UNKNOWN,   /* Shift */
+     /*   1 */   SDL_SCANCODE_UNKNOWN,   /* Ctrl */
+     /*   2 */   SDL_SCANCODE_UNKNOWN,   /* Alt */
+     /*   3 */   SDL_SCANCODE_LSHIFT,
+     /*   4 */   SDL_SCANCODE_LCTRL,
+     /*   5 */   SDL_SCANCODE_LALT,
+     /*   6 */   SDL_SCANCODE_RSHIFT,
+     /*   7 */   SDL_SCANCODE_RCTRL,
+     /*   8 */   SDL_SCANCODE_RALT,
+     /*   9 */   SDL_SCANCODE_UNKNOWN,   /* Left mouse */
+     /*  10 */   SDL_SCANCODE_UNKNOWN,   /* Center mouse */
+     /*  11 */   SDL_SCANCODE_UNKNOWN,   /* Right mouse */
+     /*  12 */   SDL_SCANCODE_UNKNOWN,
+     /*  13 */   SDL_SCANCODE_UNKNOWN,
+     /*  14 */   SDL_SCANCODE_UNKNOWN,
+     /*  15 */   SDL_SCANCODE_UNKNOWN,
+     /*  16 */   SDL_SCANCODE_Q,
+     /*  17 */   SDL_SCANCODE_3,
+     /*  18 */   SDL_SCANCODE_4,
+     /*  19 */   SDL_SCANCODE_5,
+     /*  20 */   SDL_SCANCODE_F4,
+     /*  21 */   SDL_SCANCODE_8,
+     /*  22 */   SDL_SCANCODE_F7,
+     /*  23 */   SDL_SCANCODE_MINUS,
+     /*  24 */   SDL_SCANCODE_6,         /* Duplicate of 52 */
+     /*  25 */   SDL_SCANCODE_LEFT,
+     /*  26 */   SDL_SCANCODE_KP_6,
+     /*  27 */   SDL_SCANCODE_KP_7,
+     /*  28 */   SDL_SCANCODE_F11,
+     /*  29 */   SDL_SCANCODE_F12,
+     /*  30 */   SDL_SCANCODE_F10,
+     /*  31 */   SDL_SCANCODE_SCROLLLOCK,
+     /*  32 */   SDL_SCANCODE_PRINTSCREEN,
+     /*  33 */   SDL_SCANCODE_W,
+     /*  34 */   SDL_SCANCODE_E,
+     /*  35 */   SDL_SCANCODE_T,
+     /*  36 */   SDL_SCANCODE_7,
+     /*  37 */   SDL_SCANCODE_I,
+     /*  38 */   SDL_SCANCODE_9,
+     /*  39 */   SDL_SCANCODE_0,
+     /*  40 */   SDL_SCANCODE_MINUS,     /* Duplicate of 23 */
+     /*  41 */   SDL_SCANCODE_DOWN,
+     /*  42 */   SDL_SCANCODE_KP_8,
+     /*  43 */   SDL_SCANCODE_KP_9,
+     /*  44 */   SDL_SCANCODE_PAUSE,
+     /*  45 */   SDL_SCANCODE_GRAVE,
+     /*  46 */   SDL_SCANCODE_CURRENCYUNIT,
+     /*  47 */   SDL_SCANCODE_BACKSPACE,
+     /*  48 */   SDL_SCANCODE_1,
+     /*  49 */   SDL_SCANCODE_2,
+     /*  50 */   SDL_SCANCODE_D,
+     /*  51 */   SDL_SCANCODE_R,
+     /*  52 */   SDL_SCANCODE_6,
+     /*  53 */   SDL_SCANCODE_U,
+     /*  54 */   SDL_SCANCODE_O,
+     /*  55 */   SDL_SCANCODE_P,
+     /*  56 */   SDL_SCANCODE_LEFTBRACKET,
+     /*  57 */   SDL_SCANCODE_UP,
+     /*  58 */   SDL_SCANCODE_KP_PLUS,
+     /*  59 */   SDL_SCANCODE_KP_MINUS,
+     /*  60 */   SDL_SCANCODE_KP_ENTER,
+     /*  61 */   SDL_SCANCODE_INSERT,
+     /*  62 */   SDL_SCANCODE_HOME,
+     /*  63 */   SDL_SCANCODE_PAGEUP,
+     /*  64 */   SDL_SCANCODE_CAPSLOCK,
+     /*  65 */   SDL_SCANCODE_A,
+     /*  66 */   SDL_SCANCODE_X,
+     /*  67 */   SDL_SCANCODE_F,
+     /*  68 */   SDL_SCANCODE_Y,
+     /*  69 */   SDL_SCANCODE_J,
+     /*  70 */   SDL_SCANCODE_K,
+     /*  71 */   SDL_SCANCODE_2,         /* Duplicate of 49 */
+     /*  72 */   SDL_SCANCODE_SEMICOLON, /* Duplicate of 87 */
+     /*  73 */   SDL_SCANCODE_RETURN,
+     /*  74 */   SDL_SCANCODE_KP_DIVIDE,
+     /*  75 */   SDL_SCANCODE_UNKNOWN,
+     /*  76 */   SDL_SCANCODE_KP_PERIOD,
+     /*  77 */   SDL_SCANCODE_NUMLOCKCLEAR,
+     /*  78 */   SDL_SCANCODE_PAGEDOWN,
+     /*  79 */   SDL_SCANCODE_APOSTROPHE,
+     /*  80 */   SDL_SCANCODE_UNKNOWN,
+     /*  81 */   SDL_SCANCODE_S,
+     /*  82 */   SDL_SCANCODE_C,
+     /*  83 */   SDL_SCANCODE_G,
+     /*  84 */   SDL_SCANCODE_H,
+     /*  85 */   SDL_SCANCODE_N,
+     /*  86 */   SDL_SCANCODE_L,
+     /*  87 */   SDL_SCANCODE_SEMICOLON,
+     /*  88 */   SDL_SCANCODE_RIGHTBRACKET,
+     /*  89 */   SDL_SCANCODE_DELETE,
+     /*  90 */   SDL_SCANCODE_KP_HASH,
+     /*  91 */   SDL_SCANCODE_KP_MULTIPLY,
+     /*  92 */   SDL_SCANCODE_UNKNOWN,
+     /*  93 */   SDL_SCANCODE_EQUALS,
+     /*  94 */   SDL_SCANCODE_NONUSBACKSLASH,
+     /*  95 */   SDL_SCANCODE_UNKNOWN,
+     /*  96 */   SDL_SCANCODE_TAB,
+     /*  97 */   SDL_SCANCODE_Z,
+     /*  98 */   SDL_SCANCODE_SPACE,
+     /*  99 */   SDL_SCANCODE_V,
+     /* 100 */   SDL_SCANCODE_B,
+     /* 101 */   SDL_SCANCODE_M,
+     /* 102 */   SDL_SCANCODE_COMMA,
+     /* 103 */   SDL_SCANCODE_PERIOD,
+     /* 104 */   SDL_SCANCODE_SLASH,
+     /* 105 */   SDL_SCANCODE_END,
+     /* 106 */   SDL_SCANCODE_KP_0,
+     /* 107 */   SDL_SCANCODE_KP_1,
+     /* 108 */   SDL_SCANCODE_KP_3,
+     /* 109 */   SDL_SCANCODE_UNKNOWN,
+     /* 110 */   SDL_SCANCODE_UNKNOWN,
+     /* 111 */   SDL_SCANCODE_UNKNOWN,
+     /* 112 */   SDL_SCANCODE_ESCAPE,
+     /* 113 */   SDL_SCANCODE_F1,
+     /* 114 */   SDL_SCANCODE_F2,
+     /* 115 */   SDL_SCANCODE_F3,
+     /* 116 */   SDL_SCANCODE_F5,
+     /* 117 */   SDL_SCANCODE_F6,
+     /* 118 */   SDL_SCANCODE_F8,
+     /* 119 */   SDL_SCANCODE_F9,
+     /* 120 */   SDL_SCANCODE_BACKSLASH,
+     /* 121 */   SDL_SCANCODE_RIGHT,
+     /* 122 */   SDL_SCANCODE_KP_4,
+     /* 123 */   SDL_SCANCODE_KP_5,
+     /* 124 */   SDL_SCANCODE_KP_2,
+     /* 125 */   SDL_SCANCODE_LGUI,
+     /* 126 */   SDL_SCANCODE_RGUI,
+     /* 127 */   SDL_SCANCODE_MENU
+};
+/* *INDENT-ON* */