1 files changed, 112 insertions, 0 deletions
diff --git a/src/c_screen.c b/src/c_screen.c
new file mode 100644
index 0000000..5a67f9b
--- /dev/null
+++ b/src/c_screen.c
@@ -0,0 +1,112 @@
+/*
+ * =====================
+ * ====  ===============
+ * =====================
+ * ===   ===   ====   ==
+ * ====  ==     ==  =  =
+ * ====  ==  =  ==     =
+ * ====  ==  =  ==  ====
+ * ====  ==  =  ==  =  =
+ * =  =  ===   ====   ==
+ * ==   ================
+ * =====================
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 2025, joe
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the organization nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ''AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * halfcab: src/c_screen.c
+ * Wed, 24 Sep 2025 20:29:26 +0200
+ * joe <rbo@gmx.us>
+ */
+
+#include <X11/X.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+
+#include "c_defines.h"
+#include "c_screen.h"
+
+static void
+fill_led
+(unsigned char leds[],
+ const int	i,
+ Display*	disp,
+ XImage*	img,
+ const int	min_x,
+ const int	max_x,
+ const int	min_y,
+ const int	max_y)
+{
+	XColor c;
+
+	(void)min_x;
+	(void)max_x;
+	(void)min_y;
+	(void)max_y;
+	c.pixel = XGetPixel(img, 0, 0);
+	XQueryColor(disp, DefaultColormap(disp, DefaultScreen(disp)), &c);
+	leds[i + 0] = c.red;
+	leds[i + 1] = c.green;
+	leds[i + 2] = c.blue;
+}
+
+void
+c_get_screen_colors
+(unsigned char	leds[],
+ Display*		disp)
+{
+	XImage* img;
+	const int top_leds  = NUM_LEDS / 2;
+	const int side_leds	= NUM_LEDS / 4;
+	const int top_px_per_led  = SCREEN_W / top_leds;
+	const int side_px_per_led = SCREEN_H / side_leds;
+	int i;
+
+	img = XGetImage(
+		disp, RootWindow(disp, DefaultScreen(disp)),
+		1920, 0,
+		SCREEN_W, SCREEN_H,
+		AllPlanes, ZPixmap
+		);
+	if (img == NULL) {
+		return;
+	}
+	i = 0;
+	fill_led(
+		leds, i,
+		disp, img,
+		0, side_px_per_led,
+		VERT_PIXEL_GAP + (0 * side_px_per_led),
+		VERT_PIXEL_GAP + ((0 + 1) * side_px_per_led)
+		);
+	(void)top_px_per_led;
+	XDestroyImage(img);
+}