From 1c256b892e843fb43b4521b3390ae34f11120bae Mon Sep 17 00:00:00 2001
From: Cameron Cawley <[EMAIL REDACTED]>
Date: Tue, 26 Oct 2021 13:42:34 +0100
Subject: [PATCH] riscos: Fix enumerating screen modes
---
src/video/riscos/SDL_riscosmodes.c | 68 +++++++++++++++++++++++-------
1 file changed, 52 insertions(+), 16 deletions(-)
diff --git a/src/video/riscos/SDL_riscosmodes.c b/src/video/riscos/SDL_riscosmodes.c
index 0da4f1cb81..3e383ca1a4 100644
--- a/src/video/riscos/SDL_riscosmodes.c
+++ b/src/video/riscos/SDL_riscosmodes.c
@@ -86,7 +86,7 @@ RISCOS_ModeToPixelFormat(int ncolour, int modeflags, int log2bpp)
static size_t
measure_mode_block(const int *block)
{
- size_t blockSize = (block[0] == 2) ? 7 : 5;
+ size_t blockSize = ((block[0] & 0xFF) == 3) ? 7 : 5;
while(block[blockSize] != -1) {
blockSize += 2;
}
@@ -105,18 +105,16 @@ read_mode_variable(int *block, int var)
return regs.r[2];
}
-static int *
+static SDL_bool
read_mode_block(int *block, SDL_DisplayMode *mode, SDL_bool extended)
{
int xres, yres, ncolour, modeflags, log2bpp, rate;
- int *end;
if ((block[0] & 0xFF) == 1) {
xres = block[1];
yres = block[2];
log2bpp = block[3];
rate = block[4];
- end = block + 5;
ncolour = (1 << (1 << log2bpp)) - 1;
modeflags = MODE_FLAG_TBGR;
} else if ((block[0] & 0xFF) == 3) {
@@ -126,16 +124,14 @@ read_mode_block(int *block, SDL_DisplayMode *mode, SDL_bool extended)
modeflags = block[4];
log2bpp = block[5];
rate = block[6];
- end = block + 7;
} else {
- return NULL;
+ return SDL_FALSE;
}
if (extended) {
xres = read_mode_variable(block, 11) + 1;
yres = read_mode_variable(block, 12) + 1;
log2bpp = read_mode_variable(block, 9);
- end = block + (measure_mode_block(block) / 4);
ncolour = read_mode_variable(block, 3);
modeflags = read_mode_variable(block, 0);
}
@@ -145,7 +141,53 @@ read_mode_block(int *block, SDL_DisplayMode *mode, SDL_bool extended)
mode->format = RISCOS_ModeToPixelFormat(ncolour, modeflags, log2bpp);
mode->refresh_rate = rate;
- return end;
+ return SDL_TRUE;
+}
+
+static void *
+convert_mode_block(const int *block)
+{
+ int xres, yres, log2bpp, rate, ncolour = 0, modeflags = 0;
+ size_t pos = 0;
+ int *dst;
+
+ if ((block[0] & 0xFF) == 1) {
+ xres = block[1];
+ yres = block[2];
+ log2bpp = block[3];
+ rate = block[4];
+ } else if ((block[0] & 0xFF) == 3) {
+ xres = block[1];
+ yres = block[2];
+ ncolour = block[3];
+ modeflags = block[4];
+ log2bpp = block[5];
+ rate = block[6];
+ } else {
+ return NULL;
+ }
+
+ dst = SDL_malloc(40);
+ if (!dst) {
+ return NULL;
+ }
+
+ dst[pos++] = 1;
+ dst[pos++] = xres;
+ dst[pos++] = yres;
+ dst[pos++] = log2bpp;
+ dst[pos++] = rate;
+ if (ncolour != 0) {
+ dst[pos++] = 3;
+ dst[pos++] = ncolour;
+ }
+ if (modeflags != 0) {
+ dst[pos++] = 0;
+ dst[pos++] = modeflags;
+ }
+ dst[pos++] = -1;
+
+ return dst;
}
static void *
@@ -221,24 +263,18 @@ RISCOS_GetDisplayModes(_THIS, SDL_VideoDisplay * display)
}
for (pos = block; pos < (void *)regs.r[6]; pos += *((int *)pos)) {
- size_t size;
- void *end;
-
- end = read_mode_block(pos + 4, &mode, SDL_FALSE);
- if (!end) {
+ if (!read_mode_block(pos + 4, &mode, SDL_FALSE)) {
continue;
}
if (mode.format == SDL_PIXELFORMAT_UNKNOWN)
continue;
- size = (end - pos) - 4;
- mode.driverdata = copy_memory(pos + 4, size, size + 4);
+ mode.driverdata = convert_mode_block(pos + 4);
if (!mode.driverdata) {
SDL_OutOfMemory();
break;
}
- *((int *)(mode.driverdata + size)) = -1;
if (!SDL_AddDisplayMode(display, &mode)) {
SDL_free(mode.driverdata);