load-image(wt-lcd-device)

C++ implementation

#pragma XOD evaluate_on_pin disable
#pragma XOD evaluate_on_pin enable input_UPD

// Tell XOD where it can download the libraries:
#pragma XOD require "https://github.com/Seeed-Studio/Seeed_Arduino_FS"

#include <Seeed_FS.h>

#include<stdint.h>
#include<SD/Seeed_SD.h>

node {
    //define internal state variable
    bool begun = false;

    void evaluate(Context ctx) {

        // The node responds only if there is an input pulse
        if (!isInputDirty<input_UPD>(ctx))
            return;

        if(!begun){
            //Initialise SD card
            begun = SD.begin(SDCARD_SS_PIN, SDCARD_SPI);
        }

        if (!begun) {
            // Initialization of SD card failed
            raiseError(ctx);
            return;
        }

        // Get a pointer to the `TFT_eSPI tft` class instance
        auto tft = getValue<input_DEV>(ctx);

        auto xString = getValue<input_File>(ctx);
        int N=length(xString) + 1;
        char cString[N];
        for(int i=0;i<N;i++)
            cString[i]=0;
        dump(xString, cString);

        File f = SD.open(cString, FILE_READ);
        if (!f){
            // Failed to open the file. Maybe, SD card gone,
            // try to reinit next time
            begun = false;
            raiseError(ctx);
            return;
        }
        int32_t size = f.size()-4;

        uint8_t header [4];
        f.read(header, 4);
        int16_t w = ((header[1] << 8) | header[0]);
        int16_t h = ((header[3] << 8) | header[2]);

        uint16_t *mem = new uint16_t[size/2];
        f.read(mem, size);
        tft->pushImage(getValue<input_X>(ctx), getValue<input_Y>(ctx), w, h, mem);
        delete [] mem;

        /* The following code chunk was used to facilitate loading both 8 and 16-bit images. However, for simplicity, the option to choose between 8 and 16-bit images has been removed.
        if(getValue<input_16_bit>(ctx)) {
            uint16_t *mem = new uint16_t[size/2];
            f.read(mem, size);
            tft->pushImage(getValue<input_X>(ctx), getValue<input_Y>(ctx), w, h, mem);
            delete [] mem;
        } else {
            uint8_t *mem = new uint8_t[size];
            f.read(mem, size);
            tft->pushImage(getValue<input_X>(ctx), getValue<input_Y>(ctx), w, h, mem);
            delete [] mem;
        }
        */

        f.close();
        
        emitValue<output_Done>(ctx, 1);
    }
}