canniablise my fake windows patch for redshift

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 202 insertions, 0 deletions

diff --git a/src/fake_w32gdi.c b/src/fake_w32gdi.c
new file mode 100644
index 0000000..df8fe7e
--- /dev/null
+++ b/src/fake_w32gdi.c
@@ -0,0 +1,202 @@
+/**
+ * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "fake-w32gdi.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <xcb/xcb.h>
+#include <xcb/randr.h>
+
+
+/* This file very sloppily translates Windows GDI calls to X RandR calls.
+   It should by no means be used, without additional modification, as a
+   part of a compatibility layer. The purpose of this file is only to make
+   it possible to test for logical errors in Windows specific code on
+   a GNU/Linux system under X. */
+
+
+#define GAMMA_RAMP_SIZE  256
+
+
+static xcb_connection_t* conn = NULL;
+static size_t dc_count = 0;
+static ssize_t crtc_count = -1;
+static xcb_randr_crtc_t* crtcs = NULL;
+static xcb_randr_get_screen_resources_current_reply_t* res_reply = NULL;
+
+
+/* http://msdn.microsoft.com/en-us/library/windows/desktop/dd144871(v=vs.85).aspx */
+HDC GetDC(HWND hWnd)
+{
+  (void) hWnd;
+  return CreateDC(TEXT("DISPLAY"), "0", NULL, NULL);
+}
+
+
+/* http://msdn.microsoft.com/en-us/library/windows/desktop/dd162920(v=vs.85).aspx */
+int ReleaseDC(HWND hWnd, HDC hDC)
+{
+  (void) hWnd;
+  (void) hDC;
+  
+  dc_count--;
+  if (dc_count == 0) {
+    if (conn != NULL)
+      xcb_disconnect(conn);
+    conn = NULL;
+    if (res_reply != NULL)
+      free(res_reply);
+    res_reply = NULL;
+  }
+  
+  return 1;
+}
+
+
+/* http://msdn.microsoft.com/en-us/library/windows/desktop/dd144877(v=vs.85).aspx */
+int GetDeviceCaps(HDC hDC, int nIndex)
+{
+  (void) hDC;
+  
+  return CM_GAMMA_RAMP + nIndex - COLORMGMTCAPS;
+}
+
+
+/* http://msdn.microsoft.com/en-us/library/windows/desktop/dd372194(v=vs.85).aspx */
+BOOL SetDeviceGammaRamp(HDC hDC, LPVOID lpRamp)
+{
+  xcb_void_cookie_t gamma_cookie =
+    xcb_randr_set_crtc_gamma_checked(conn, *(xcb_randr_crtc_t*)hDC, GAMMA_RAMP_SIZE,
+				     ((uint16_t *)lpRamp) + 0 * GAMMA_RAMP_SIZE,
+				     ((uint16_t *)lpRamp) + 1 * GAMMA_RAMP_SIZE,
+				     ((uint16_t *)lpRamp) + 2 * GAMMA_RAMP_SIZE);
+  xcb_generic_error_t* error = xcb_request_check(conn, gamma_cookie);
+  return error == NULL ? TRUE : FALSE;
+}
+
+
+/* http://msdn.microsoft.com/en-us/library/windows/desktop/dd316946(v=vs.85).aspx */
+BOOL GetDeviceGammaRamp(HDC hDC, LPVOID lpRamp)
+{
+  xcb_randr_get_crtc_gamma_cookie_t gamma_cookie;
+  xcb_randr_get_crtc_gamma_reply_t* gamma_reply;
+  xcb_generic_error_t* error;
+  
+  gamma_cookie = xcb_randr_get_crtc_gamma(conn, *(xcb_randr_crtc_t*)hDC);
+  gamma_reply = xcb_randr_get_crtc_gamma_reply(conn, gamma_cookie, &error);
+  
+  if (error) return FALSE;
+  
+#define DEST_RAMP(I)  (((uint16_t*)lpRamp) + (I) * GAMMA_RAMP_SIZE)
+#define SRC_RAMP(C)  (xcb_randr_get_crtc_gamma_##C(gamma_reply))
+  
+  memcpy(DEST_RAMP(0), SRC_RAMP(red),   GAMMA_RAMP_SIZE * sizeof(uint16_t));
+  memcpy(DEST_RAMP(1), SRC_RAMP(green), GAMMA_RAMP_SIZE * sizeof(uint16_t));
+  memcpy(DEST_RAMP(2), SRC_RAMP(blue),  GAMMA_RAMP_SIZE * sizeof(uint16_t));
+  
+#undef SRC_RAMP
+#undef DEST_RAMP
+  
+  free(gamma_reply);
+  return TRUE;
+}
+
+
+/* http://msdn.microsoft.com/en-us/library/windows/desktop/dd183490(v=vs.85).aspx */
+HDC CreateDC(LPCTSTR lpszDriver, LPCTSTR lpszDevice, void *lpszOutput, void *lpInitData)
+{
+  (void) lpszOutput;
+  (void) lpInitData;
+  
+  if (strcmp(lpszDriver, "DISPLAY"))
+    return NULL;
+  
+  int crtc_index = atoi(lpszDevice);
+  
+  if (dc_count == 0)
+    {
+      xcb_generic_error_t *error;
+      xcb_screen_iterator_t iter;
+      xcb_randr_get_screen_resources_current_cookie_t res_cookie;
+      
+      conn = xcb_connect(NULL, NULL);
+      
+      iter = xcb_setup_roots_iterator(xcb_get_setup(conn));
+      res_cookie = xcb_randr_get_screen_resources_current(conn, iter.data->root);
+      res_reply = xcb_randr_get_screen_resources_current_reply(conn, res_cookie, &error);
+      
+      if (error)
+	{
+	  xcb_disconnect(conn);
+	  crtc_count = -1;
+	  return NULL;
+	}
+      
+      crtc_count = res_reply->num_crtcs;
+      crtcs = xcb_randr_get_screen_resources_current_crtcs(res_reply);
+    }
+  
+  if (crtc_index >= crtc_count)
+    {
+      if (dc_count == 0)
+	{
+	  xcb_disconnect(conn);
+	  crtc_count = -1;
+	}
+      return NULL;
+    }
+  
+  dc_count++;
+  return crtcs + crtc_index;
+}
+
+
+/* http://msdn.microsoft.com/en-us/library/windows/desktop/dd162609(v=vs.85).aspx */
+BOOL EnumDisplayDevices(LPCTSTR lpDevice, DWORD iDevNum, PDISPLAY_DEVICE lpDisplayDevice, DWORD dwFlags)
+{
+  (void) dwFlags;
+  
+  size_t count = (size_t)crtc_count;
+  if (lpDevice != NULL)
+    {
+      fprintf(stderr, "lpDevice (argument 1) for EnumDisplayDevices should be NULL\n");
+      abort();
+      return FALSE;
+    }
+  if (crtc_count < 0)
+    {
+      if (GetDC(NULL) == NULL)
+	return FALSE;
+      dc_count = 0;
+      count = (size_t)crtc_count;
+      ReleaseDC(NULL, NULL);
+    }
+  if (iDevNum >= count)
+    return FALSE;
+  if (lpDisplayDevice->cb != sizeof(DISPLAY_DEVICE))
+    {
+      fprintf(stderr, "lpDisplayDevice->cb for EnumDisplayDevices is not sizeof(DISPLAY_DEVICE)\n");
+      abort();
+      return FALSE;
+    }
+  sprintf(lpDisplayDevice->DeviceName, "%i", iDevNum);
+  lpDisplayDevice->StateFlags = DISPLAY_DEVICE_ACTIVE;
+  return TRUE;
+}
+