Add a barebones RISC OS video driver

2020-02-13 21:55:08 +00:00 · 2020-02-13 21:55:08 +00:00 · 25c71748ad
commit 25c71748ad
parent a559864968
16 changed files with 675 additions and 2 deletions
--- a/src/video/riscos/SDL_riscosframebuffer.c
+++ b/src/video/riscos/SDL_riscosframebuffer.c
@ -0,0 +1,148 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2018 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_internal.h"
+
+#if SDL_VIDEO_DRIVER_RISCOS
+
+#include "../SDL_sysvideo.h"
+#include "SDL_riscosframebuffer_c.h"
+#include "SDL_riscosvideo.h"
+
+#include <kernel.h>
+#include <swis.h>
+
+#define DUMMY_SURFACE   "_SDL_DummySurface"
+
+typedef struct {
+    Uint32 size;
+    Uint32 count;
+    Uint32 start;
+    Uint32 end;
+} sprite_area;
+
+int SDL_RISCOS_CreateWindowFramebuffer(_THIS, SDL_Window * window, Uint32 * format, void ** pixels, int *pitch)
+{
+    const char *sprite_name = "display";
+    int width, height, size, bytesPerRow;
+    unsigned int sprite_mode;
+    _kernel_oserror *error;
+    _kernel_swi_regs regs;
+    sprite_area *buffer;
+    Uint32 pixelformat;
+    SDL_DisplayMode mode;
+
+    /* Free the old framebuffer surface */
+    buffer = (sprite_area *) SDL_SetWindowData(window, DUMMY_SURFACE, NULL);
+    SDL_free(buffer);
+
+    /* Create a new one */
+    SDL_GetWindowSize(window, &width, &height);
+    SDL_GetCurrentDisplayMode(SDL_GetWindowDisplayIndex(window), &mode);
+
+    if ((SDL_ISPIXELFORMAT_PACKED(mode.format) || SDL_ISPIXELFORMAT_ARRAY(mode.format))) {
+        pixelformat = mode.format;
+        sprite_mode = (unsigned int)mode.driverdata;
+    } else {
+        pixelformat = SDL_PIXELFORMAT_BGR888;
+        sprite_mode = (1 | (90 << 1) | (90 << 14) | (6 << 27));
+    }
+
+    bytesPerRow = SDL_BYTESPERPIXEL(pixelformat) * width;
+    if ((bytesPerRow & 3) != 0) {
+        bytesPerRow += 4 - (bytesPerRow & 3);
+    }
+    size = 60 + (bytesPerRow * height);
+
+    buffer = SDL_malloc(size);
+    if (!buffer) {
+        SDL_OutOfMemory();
+        return -1;
+    }
+
+    /* Initialise a sprite area */
+
+    buffer->size  = size;
+    buffer->start = 16;
+
+    regs.r[0] = 256+9;
+    regs.r[1] = (unsigned int)buffer;
+    error = _kernel_swi(OS_SpriteOp, &regs, &regs);
+    if (error != NULL) {
+        SDL_SetError("Unable to initialise sprite area: %s (%i)", error->errmess, error->errnum);
+        SDL_free(buffer);
+        return -1;
+    }
+
+    regs.r[0] = 256+15;
+    regs.r[1] = (unsigned int)buffer;
+    regs.r[2] = (unsigned int)sprite_name;
+    regs.r[3] = 0;
+    regs.r[4] = width;
+    regs.r[5] = height;
+    regs.r[6] = sprite_mode;
+    error = _kernel_swi(OS_SpriteOp, &regs, &regs);
+    if (error != NULL) {
+        SDL_SetError("Unable to create sprite: %s (%i)", error->errmess, error->errnum);
+        SDL_free(buffer);
+        return -1;
+    }
+
+    /* Save the info and return! */
+    SDL_SetWindowData(window, DUMMY_SURFACE, buffer);
+    *format = pixelformat;
+    *pixels = ((Uint8 *)buffer) + 60;
+    *pitch = bytesPerRow;
+
+    return 0;
+}
+
+int SDL_RISCOS_UpdateWindowFramebuffer(_THIS, SDL_Window * window, const SDL_Rect * rects, int numrects)
+{
+    _kernel_swi_regs regs;
+    sprite_area *buffer;
+
+    buffer = (sprite_area *) SDL_GetWindowData(window, DUMMY_SURFACE);
+    if (!buffer) {
+        return SDL_SetError("Couldn't find sprite for window");
+    }
+
+    regs.r[0] = 512+52;
+    regs.r[1] = (unsigned int)buffer;
+    regs.r[2] = (unsigned int)buffer + buffer->start;
+    regs.r[3] = window->x * 2;
+    regs.r[4] = window->y * 2;
+    regs.r[5] = 0x50;
+    regs.r[6] = 0;
+    regs.r[7] = 0;
+    _kernel_swi(OS_SpriteOp, &regs, &regs);
+
+    return 0;
+}
+
+void SDL_RISCOS_DestroyWindowFramebuffer(_THIS, SDL_Window * window)
+{
+    sprite_area *buffer = (sprite_area *) SDL_SetWindowData(window, DUMMY_SURFACE, NULL);
+    SDL_free(buffer);
+}
+
+#endif /* SDL_VIDEO_DRIVER_RISCOS */
+
+/* vi: set ts=4 sw=4 expandtab: */