example: move spi master example to a subfolder

examples/peripherals/spi_master/lcd/main/pretty_effect.h

@@ -0,0 +1,30 @@
+/*
+   This example code is in the Public Domain (or CC0 licensed, at your option.)
+
+   Unless required by applicable law or agreed to in writing, this
+   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+   CONDITIONS OF ANY KIND, either express or implied.
+*/
+
+#pragma once
+#include <stdint.h>
+#include "esp_err.h"
+
+
+/**
+ * @brief Calculate the effect for a bunch of lines.
+ *
+ * @param dest Destination for the pixels. Assumed to be LINECT * 320 16-bit pixel values.
+ * @param line Starting line of the chunk of lines.
+ * @param frame Current frame, used for animation
+ * @param linect Amount of lines to calculate
+ */
+void pretty_effect_calc_lines(uint16_t *dest, int line, int frame, int linect);
+
+
+/**
+ * @brief Initialize the effect
+ *
+ * @return ESP_OK on success, an error from the jpeg decoder otherwise.
+ */
+esp_err_t pretty_effect_init(void);