From cf5c010fe47b9df2919ecbf248afe33b37c1263a Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Mon, 4 Aug 2025 01:46:01 -0400
Subject: libgfx: draw: Add gfx_get_pix() function

Introduce gfx routine to grab the RGB value of a specific pixel at a
specific location on the screen.

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 lib/libgfx/include/libgfx/draw.h |  1 +
 lib/libgfx/src/draw.c            | 28 ++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/lib/libgfx/include/libgfx/draw.h b/lib/libgfx/include/libgfx/draw.h
index 9f56f6c..96fe35a 100644
--- a/lib/libgfx/include/libgfx/draw.h
+++ b/lib/libgfx/include/libgfx/draw.h
@@ -103,6 +103,7 @@ struct gfx_point {
 
 int gfx_draw_shape(struct gfx_ctx *ctx, const struct gfx_shape *shape);
 int gfx_plot_point(struct gfx_ctx *ctx, const struct gfx_point *point);
+color_t gfx_get_pix(struct gfx_ctx *ctx, uint32_t x, uint32_t y);
 
 __always_inline static inline size_t
 gfx_io_index(struct gfx_ctx *ctx, scrpos_t x, scrpos_t y)
diff --git a/lib/libgfx/src/draw.c b/lib/libgfx/src/draw.c
index 9ef8630..784110a 100644
--- a/lib/libgfx/src/draw.c
+++ b/lib/libgfx/src/draw.c
@@ -128,6 +128,34 @@ gfx_plot_point(struct gfx_ctx *ctx, const struct gfx_point *point)
     return 0;
 }
 
+/*
+ * Grab the RGB value of a single pixel on
+ * the scren.
+ *
+ * @ctx: Graphics context pointer
+ * @x: X position to sample
+ * @y: Y position to sample
+ */
+color_t
+gfx_get_pix(struct gfx_ctx *ctx, uint32_t x, uint32_t y)
+{
+    const color_t ERROR_COLOR = GFX_BLACK;
+    uint32_t index;
+
+    /* The 'ctx' argument is required */
+    if (ctx == NULL) {
+        return ERROR_COLOR;
+    }
+
+    /* Are we within bounds of the screen */
+    if (gfx_pixel_bounds(ctx, x, y) < 0) {
+        return ERROR_COLOR;
+    }
+
+    index = gfx_io_index(ctx, x, y);
+    return ctx->io[index];
+}
+
 /*
  * Draw a shape onto the screen
  *
-- 
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