From fd79a4f42712f5640d43e46f245498e99705f6d8 Mon Sep 17 00:00:00 2001
From: Akos Becsey <becsey.a@gmail.com>
Date: Wed, 19 Jun 2024 15:34:31 +0200
Subject: [PATCH] feat(glcdc): screen rotation support

---
 .../driver/display/renesas_glcdc.rst          | 20 ++++++++++++
 .../display/renesas_glcdc/lv_renesas_glcdc.c  | 32 +++++++++++++++++--
 2 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/docs/integration/driver/display/renesas_glcdc.rst b/docs/integration/driver/display/renesas_glcdc.rst
index de7cfe019..b3d4dbd65 100644
--- a/docs/integration/driver/display/renesas_glcdc.rst
+++ b/docs/integration/driver/display/renesas_glcdc.rst
@@ -59,3 +59,23 @@ Buffer swapping can be activated by passing a second buffer of same size instead
 
     lv_display_t * disp = lv_renesas_glcdc_partial_create(partial_draw_buf, NULL, sizeof(partial_draw_buf));
     lv_display_set_default(disp);
+
+.. note::
+
+    Partial mode can be activated via the macro in ``src/board_init.c`` file of the demo projects.
+
+
+Screen rotation
+"""""""""""""""
+
+Software based screen rotation is supported in partial mode. It uses the common API, no extra configuration is required:
+
+.. code:: c
+
+    lv_display_set_rotation(lv_display_get_default(), LV_DISP_ROTATION_90);
+    /* OR */
+    lv_display_set_rotation(lv_display_get_default(), LV_DISP_ROTATION_180);
+    /* OR */
+    lv_display_set_rotation(lv_display_get_default(), LV_DISP_ROTATION_270);
+
+Make sure the heap is large enough, as a buffer with the same size as the partial buffer will be allocated.
diff --git a/src/drivers/display/renesas_glcdc/lv_renesas_glcdc.c b/src/drivers/display/renesas_glcdc/lv_renesas_glcdc.c
index 342286a1d..16de73472 100644
--- a/src/drivers/display/renesas_glcdc/lv_renesas_glcdc.c
+++ b/src/drivers/display/renesas_glcdc/lv_renesas_glcdc.c
@@ -36,6 +36,7 @@
 
 #include <stdbool.h>
 #include "../../../display/lv_display_private.h"
+#include "../../../draw/sw/lv_draw_sw.h"
 
 /*********************
  *      DEFINES
@@ -76,6 +77,9 @@ static glcdc_runtime_cfg_t  g_layer_change;
 display_t g_display0_cfg;
 #endif /*_RENESAS_RX_*/
 
+static void * rotation_buffer = NULL;
+static uint32_t partial_buffer_size = 0;
+
 /**********************
  *      MACROS
  **********************/
@@ -92,6 +96,7 @@ lv_display_t * lv_renesas_glcdc_direct_create(void)
 
 lv_display_t * lv_renesas_glcdc_partial_create(void * buf1, void * buf2, size_t buf_size)
 {
+    partial_buffer_size = buf_size;
     return glcdc_create(buf1, buf2, buf_size, LV_DISPLAY_RENDER_MODE_PARTIAL);
 }
 
@@ -277,13 +282,36 @@ static void flush_wait_direct(lv_display_t * display)
 
 static void flush_partial(lv_display_t * display, const lv_area_t * area, uint8_t * px_map)
 {
-    LV_UNUSED(display);
+    uint16_t * img = (uint16_t *)px_map;
+
+    lv_color_format_t cf = lv_display_get_color_format(display);
+    lv_display_rotation_t rotation = lv_display_get_rotation(display);
+
+    if(rotation != LV_DISPLAY_ROTATION_0) {
+        int32_t w = lv_area_get_width(area);
+        int32_t h = lv_area_get_height(area);
+        uint32_t w_stride = lv_draw_buf_width_to_stride(w, cf);
+        uint32_t h_stride = lv_draw_buf_width_to_stride(h, cf);
+
+        // only allocate if rotation is actually being used
+        if(!rotation_buffer) {
+            rotation_buffer = lv_malloc(partial_buffer_size);
+            LV_ASSERT_MALLOC(rotation_buffer);
+        }
+
+        if(rotation == LV_DISPLAY_ROTATION_180)
+            lv_draw_sw_rotate(img, rotation_buffer, w, h, w_stride, w_stride, rotation, cf);
+        else /* 90 or 270 */
+            lv_draw_sw_rotate(img, rotation_buffer, w, h, w_stride, h_stride, rotation, cf);
+
+        img = rotation_buffer;
+        lv_display_rotate_area(display, (lv_area_t *)area);
+    }
 
     int32_t w = lv_area_get_width(area);
     int32_t h = lv_area_get_height(area);
 
     uint16_t * fb = (uint16_t *)fb_background[1];
-    uint16_t * img = (uint16_t *)px_map;
 
     fb = fb + area->y1 * DISPLAY_HSIZE_INPUT0;
     fb = fb + area->x1;