Help with GD.Tag and BlendFunc

[arcadetv]

I'm displaying 4 rows with 5 rects on the screen. I tag them using GD.Tag and while one of them is touched I also display the Tag value for debugging.
This is not doing what I want, what am I doing wrong?

Also when the GD.BlendFunc(ONE, ZERO); is active any Text that is displayed is boxed and not readable anymore, how can I revert the BlendFunc to normal/not blending?

#include <EEPROM.h>
#include <SPI.h>
#include <GD2.h>

int currentLine = 0;

void setup()
{
 GD.begin(0);
}

void loop()
{
   GD.get_inputs();
   
   GD.ClearColorRGB(0x000000);
   GD.Clear();
   GD.cmd_gradient(0, 40, 0x5096fa,
                   0, 272, 0x62a1fb);
   GD.BitmapLayout(L8, 1, 1);
   //GD.BlendFunc(ONE, ZERO);
   GD.BitmapSize(NEAREST, REPEAT, REPEAT, 80, 40);
   GD.Begin(BITMAPS);
   
   int i = 0;
   for(int ry = 0; ry < 4; ry++){
       for(int rx = 0; rx < 5; rx++){
           GD.Tag(i);
           if(i == currentLine){
               GD.ColorRGB(0,0,0);
           }else{
               GD.ColorRGB(255, 255, 255);
           }
           int xpos = (rx*98)+5;
           int ypos = (ry*51)+5;
           GD.Vertex2ii(xpos, ypos);
           i++;
       }
   }
   
   if (GD.inputs.x != -32768) {
       currentLine = GD.inputs.tag;
   }
   GD.ColorRGB(0,0,0);
   GD.cmd_number(240, 230, 16, OPT_CENTERX, GD.inputs.tag);
   GD.swap();
}

[jamesbowman]

I just ran it, and the issue is the GD.Begin. The zero argument means "do not initialize any extras". This means that the touchscreen does not get initialized.

Instead do:

 GD.begin(GD_CALIBRATE);
and it works fine.

To restore the blendfunc to its default, you can do either:

GD.BlendFunc(SRC_ALPHA, ONE_MINUS_SRC_ALPHA);
or you can save/restore *all* the graphics state like this:

GD.SaveContext();
GD.BlendFunc(ONE, ZERO);
...
GD.RestoreContext();
Oh, this code is sourcing a 1x1 pixel bitmap from address zero. This is unintialized at boot. Suggest adding something like this to set it:

GD.wr(0, 255);

[arcadetv]

Great input! Thanks!! And it works ^^

[arcadetv]

GD.wr(0, 255);
There's no info on the "wr" method in the cookbook...
What does it do?

[arcadetv]

Giving back:
For everyone who wants a simple multi-button-interface if you wanna control some hardware-stuff for example:


#include <EEPROM.h>
#include <SPI.h>
#include <GD2.h>

int currentLine = 0;
const int totalLines = 20;
int currentButton_touch = 1;
int lastButton_touch = 0;
void setup()
{
 GD.begin(GD_CALIBRATE);
}

int debounce_touch(int last_touch)
{
 int current_touch = GD.inputs.tag;
 if (last_touch != current_touch)
 {
   delay(10);
   current_touch = GD.inputs.tag;
 }
 return current_touch;
}

void loop()
{
   GD.SaveContext();
   GD.get_inputs();
   
   GD.ClearColorRGB(0x000000);
   GD.Clear();
   GD.cmd_gradient(0, 40, 0x5096fa,
                   0, 272, 0x62a1fb);
   GD.BitmapLayout(L8, 1, 1);
   GD.BlendFunc(ONE, ZERO);
   GD.BitmapSize(NEAREST, REPEAT, REPEAT, 80, 40);
   GD.Begin(BITMAPS);
   
   int i = 0;
   for(int ry = 0; ry < 4; ry++){
       for(int rx = 0; rx < 5; rx++){
           GD.Tag(i+1);
           if(i == currentLine){
               GD.ColorRGB(0,0,0);
           }else{
               GD.ColorRGB(255, 255, 255);
           }
           int xpos = (rx*98)+5;
           int ypos = (ry*51)+5;
           GD.Vertex2ii(xpos, ypos);
           i++;
       }
   }
   
   currentButton_touch = debounce_touch(lastButton_touch);
   if (GD.inputs.x != -32768 && currentButton_touch <= totalLines && currentButton_touch >= 0) {
       if (lastButton_touch != currentButton_touch){
           currentLine = GD.inputs.tag-1;
       }
   }
   GD.RestoreContext();
   
   i = 0;
   for(int ry = 0; ry < 4; ry++){
       for(int rx = 0; rx < 5; rx++){
           GD.Tag(i+1);
           if(i == currentLine){
               GD.ColorRGB(255, 255, 255);
           }else{
               GD.ColorRGB(0,0,0);
           }
           int xpos = (rx*98)+5;
           int ypos = (ry*51)+5;
           GD.cmd_number(xpos+40, ypos+12, 26, OPT_CENTERX, i+1);
           i++;
       }
   }
   
   GD.ColorRGB(0,0,0);
   GD.cmd_text(200, 220, 31, OPT_CENTERX, "Current Line: ");
   GD.cmd_number(350, 220, 31, OPT_CENTERX, currentLine+1);
   GD.swap();
}

[jamesbowman]

Awesome. thanks. Did you see cmd_button() as a way of rendering buttons?

GD.wr(addr, b) writes a single byte value b to GD2 memory.