349 lines
7.3 KiB
C++
349 lines
7.3 KiB
C++
/*
|
|
|
|
Example sketch for TFT_eSPI library.
|
|
|
|
No fonts are needed.
|
|
|
|
Draws a 3d rotating cube on the TFT screen.
|
|
|
|
Original code was found at http://forum.freetronics.com/viewtopic.php?f=37&t=5495
|
|
|
|
*/
|
|
|
|
#define BLACK 0x0000
|
|
#define WHITE 0xFFFF
|
|
|
|
#include <SPI.h>
|
|
|
|
#include <TFT_eSPI.h> // Hardware-specific library
|
|
|
|
TFT_eSPI tft = TFT_eSPI(); // Invoke custom library
|
|
|
|
int16_t h;
|
|
int16_t w;
|
|
|
|
int inc = -2;
|
|
|
|
float xx, xy, xz;
|
|
float yx, yy, yz;
|
|
float zx, zy, zz;
|
|
|
|
float fact;
|
|
|
|
int Xan, Yan;
|
|
|
|
int Xoff;
|
|
int Yoff;
|
|
int Zoff;
|
|
|
|
struct Point3d
|
|
{
|
|
int x;
|
|
int y;
|
|
int z;
|
|
};
|
|
|
|
struct Point2d
|
|
{
|
|
int x;
|
|
int y;
|
|
};
|
|
|
|
int LinestoRender; // lines to render.
|
|
int OldLinestoRender; // lines to render just in case it changes. this makes sure the old lines all get erased.
|
|
|
|
struct Line3d
|
|
{
|
|
Point3d p0;
|
|
Point3d p1;
|
|
};
|
|
|
|
struct Line2d
|
|
{
|
|
Point2d p0;
|
|
Point2d p1;
|
|
};
|
|
|
|
Line3d Lines[20];
|
|
Line2d Render[20];
|
|
Line2d ORender[20];
|
|
|
|
/***********************************************************************************************************************************/
|
|
void setup() {
|
|
|
|
tft.init();
|
|
|
|
h = tft.height();
|
|
w = tft.width();
|
|
|
|
tft.setRotation(1);
|
|
|
|
tft.fillScreen(TFT_BLACK);
|
|
|
|
cube();
|
|
|
|
fact = 180 / 3.14159259; // conversion from degrees to radians.
|
|
|
|
Xoff = 240; // Position the centre of the 3d conversion space into the centre of the TFT screen.
|
|
Yoff = 160;
|
|
Zoff = 550; // Z offset in 3D space (smaller = closer and bigger rendering)
|
|
}
|
|
|
|
/***********************************************************************************************************************************/
|
|
void loop() {
|
|
|
|
// Rotate around x and y axes in 1 degree increments
|
|
Xan++;
|
|
Yan++;
|
|
|
|
Yan = Yan % 360;
|
|
Xan = Xan % 360; // prevents overflow.
|
|
|
|
SetVars(); //sets up the global vars to do the 3D conversion.
|
|
|
|
// Zoom in and out on Z axis within limits
|
|
// the cube intersects with the screen for values < 160
|
|
Zoff += inc;
|
|
if (Zoff > 500) inc = -1; // Switch to zoom in
|
|
else if (Zoff < 160) inc = 1; // Switch to zoom out
|
|
|
|
for (int i = 0; i < LinestoRender ; i++)
|
|
{
|
|
ORender[i] = Render[i]; // stores the old line segment so we can delete it later.
|
|
ProcessLine(&Render[i], Lines[i]); // converts the 3d line segments to 2d.
|
|
}
|
|
RenderImage(); // go draw it!
|
|
|
|
delay(14); // Delay to reduce loop rate (reduces flicker caused by aliasing with TFT screen refresh rate)
|
|
}
|
|
|
|
/***********************************************************************************************************************************/
|
|
void RenderImage( void)
|
|
{
|
|
// renders all the lines after erasing the old ones.
|
|
// in here is the only code actually interfacing with the OLED. so if you use a different lib, this is where to change it.
|
|
|
|
for (int i = 0; i < OldLinestoRender; i++ )
|
|
{
|
|
tft.drawLine(ORender[i].p0.x, ORender[i].p0.y, ORender[i].p1.x, ORender[i].p1.y, BLACK); // erase the old lines.
|
|
}
|
|
|
|
|
|
for (int i = 0; i < LinestoRender; i++ )
|
|
{
|
|
uint16_t color = TFT_BLUE;
|
|
if (i < 4) color = TFT_RED;
|
|
if (i > 7) color = TFT_GREEN;
|
|
tft.drawLine(Render[i].p0.x, Render[i].p0.y, Render[i].p1.x, Render[i].p1.y, color);
|
|
}
|
|
OldLinestoRender = LinestoRender;
|
|
}
|
|
|
|
/***********************************************************************************************************************************/
|
|
// Sets the global vars for the 3d transform. Any points sent through "process" will be transformed using these figures.
|
|
// only needs to be called if Xan or Yan are changed.
|
|
void SetVars(void)
|
|
{
|
|
float Xan2, Yan2, Zan2;
|
|
float s1, s2, s3, c1, c2, c3;
|
|
|
|
Xan2 = Xan / fact; // convert degrees to radians.
|
|
Yan2 = Yan / fact;
|
|
|
|
// Zan is assumed to be zero
|
|
|
|
s1 = sin(Yan2);
|
|
s2 = sin(Xan2);
|
|
|
|
c1 = cos(Yan2);
|
|
c2 = cos(Xan2);
|
|
|
|
xx = c1;
|
|
xy = 0;
|
|
xz = -s1;
|
|
|
|
yx = (s1 * s2);
|
|
yy = c2;
|
|
yz = (c1 * s2);
|
|
|
|
zx = (s1 * c2);
|
|
zy = -s2;
|
|
zz = (c1 * c2);
|
|
}
|
|
|
|
|
|
/***********************************************************************************************************************************/
|
|
// processes x1,y1,z1 and returns rx1,ry1 transformed by the variables set in SetVars()
|
|
// fairly heavy on floating point here.
|
|
// uses a bunch of global vars. Could be rewritten with a struct but not worth the effort.
|
|
void ProcessLine(struct Line2d *ret, struct Line3d vec)
|
|
{
|
|
float zvt1;
|
|
int xv1, yv1, zv1;
|
|
|
|
float zvt2;
|
|
int xv2, yv2, zv2;
|
|
|
|
int rx1, ry1;
|
|
int rx2, ry2;
|
|
|
|
int x1;
|
|
int y1;
|
|
int z1;
|
|
|
|
int x2;
|
|
int y2;
|
|
int z2;
|
|
|
|
int Ok;
|
|
|
|
x1 = vec.p0.x;
|
|
y1 = vec.p0.y;
|
|
z1 = vec.p0.z;
|
|
|
|
x2 = vec.p1.x;
|
|
y2 = vec.p1.y;
|
|
z2 = vec.p1.z;
|
|
|
|
Ok = 0; // defaults to not OK
|
|
|
|
xv1 = (x1 * xx) + (y1 * xy) + (z1 * xz);
|
|
yv1 = (x1 * yx) + (y1 * yy) + (z1 * yz);
|
|
zv1 = (x1 * zx) + (y1 * zy) + (z1 * zz);
|
|
|
|
zvt1 = zv1 - Zoff;
|
|
|
|
if ( zvt1 < -5) {
|
|
rx1 = 256 * (xv1 / zvt1) + Xoff;
|
|
ry1 = 256 * (yv1 / zvt1) + Yoff;
|
|
Ok = 1; // ok we are alright for point 1.
|
|
}
|
|
|
|
xv2 = (x2 * xx) + (y2 * xy) + (z2 * xz);
|
|
yv2 = (x2 * yx) + (y2 * yy) + (z2 * yz);
|
|
zv2 = (x2 * zx) + (y2 * zy) + (z2 * zz);
|
|
|
|
zvt2 = zv2 - Zoff;
|
|
|
|
if ( zvt2 < -5) {
|
|
rx2 = 256 * (xv2 / zvt2) + Xoff;
|
|
ry2 = 256 * (yv2 / zvt2) + Yoff;
|
|
} else
|
|
{
|
|
Ok = 0;
|
|
}
|
|
|
|
if (Ok == 1) {
|
|
|
|
ret->p0.x = rx1;
|
|
ret->p0.y = ry1;
|
|
|
|
ret->p1.x = rx2;
|
|
ret->p1.y = ry2;
|
|
}
|
|
// The ifs here are checks for out of bounds. needs a bit more code here to "safe" lines that will be way out of whack, so they don't get drawn and cause screen garbage.
|
|
|
|
}
|
|
|
|
/***********************************************************************************************************************************/
|
|
// line segments to draw a cube. basically p0 to p1. p1 to p2. p2 to p3 so on.
|
|
void cube(void)
|
|
{
|
|
// Front Face.
|
|
|
|
Lines[0].p0.x = -50;
|
|
Lines[0].p0.y = -50;
|
|
Lines[0].p0.z = 50;
|
|
Lines[0].p1.x = 50;
|
|
Lines[0].p1.y = -50;
|
|
Lines[0].p1.z = 50;
|
|
|
|
Lines[1].p0.x = 50;
|
|
Lines[1].p0.y = -50;
|
|
Lines[1].p0.z = 50;
|
|
Lines[1].p1.x = 50;
|
|
Lines[1].p1.y = 50;
|
|
Lines[1].p1.z = 50;
|
|
|
|
Lines[2].p0.x = 50;
|
|
Lines[2].p0.y = 50;
|
|
Lines[2].p0.z = 50;
|
|
Lines[2].p1.x = -50;
|
|
Lines[2].p1.y = 50;
|
|
Lines[2].p1.z = 50;
|
|
|
|
Lines[3].p0.x = -50;
|
|
Lines[3].p0.y = 50;
|
|
Lines[3].p0.z = 50;
|
|
Lines[3].p1.x = -50;
|
|
Lines[3].p1.y = -50;
|
|
Lines[3].p1.z = 50;
|
|
|
|
|
|
//back face.
|
|
|
|
Lines[4].p0.x = -50;
|
|
Lines[4].p0.y = -50;
|
|
Lines[4].p0.z = -50;
|
|
Lines[4].p1.x = 50;
|
|
Lines[4].p1.y = -50;
|
|
Lines[4].p1.z = -50;
|
|
|
|
Lines[5].p0.x = 50;
|
|
Lines[5].p0.y = -50;
|
|
Lines[5].p0.z = -50;
|
|
Lines[5].p1.x = 50;
|
|
Lines[5].p1.y = 50;
|
|
Lines[5].p1.z = -50;
|
|
|
|
Lines[6].p0.x = 50;
|
|
Lines[6].p0.y = 50;
|
|
Lines[6].p0.z = -50;
|
|
Lines[6].p1.x = -50;
|
|
Lines[6].p1.y = 50;
|
|
Lines[6].p1.z = -50;
|
|
|
|
Lines[7].p0.x = -50;
|
|
Lines[7].p0.y = 50;
|
|
Lines[7].p0.z = -50;
|
|
Lines[7].p1.x = -50;
|
|
Lines[7].p1.y = -50;
|
|
Lines[7].p1.z = -50;
|
|
|
|
|
|
// now the 4 edge lines.
|
|
|
|
Lines[8].p0.x = -50;
|
|
Lines[8].p0.y = -50;
|
|
Lines[8].p0.z = 50;
|
|
Lines[8].p1.x = -50;
|
|
Lines[8].p1.y = -50;
|
|
Lines[8].p1.z = -50;
|
|
|
|
Lines[9].p0.x = 50;
|
|
Lines[9].p0.y = -50;
|
|
Lines[9].p0.z = 50;
|
|
Lines[9].p1.x = 50;
|
|
Lines[9].p1.y = -50;
|
|
Lines[9].p1.z = -50;
|
|
|
|
Lines[10].p0.x = -50;
|
|
Lines[10].p0.y = 50;
|
|
Lines[10].p0.z = 50;
|
|
Lines[10].p1.x = -50;
|
|
Lines[10].p1.y = 50;
|
|
Lines[10].p1.z = -50;
|
|
|
|
Lines[11].p0.x = 50;
|
|
Lines[11].p0.y = 50;
|
|
Lines[11].p0.z = 50;
|
|
Lines[11].p1.x = 50;
|
|
Lines[11].p1.y = 50;
|
|
Lines[11].p1.z = -50;
|
|
|
|
LinestoRender = 12;
|
|
OldLinestoRender = LinestoRender;
|
|
|
|
}
|
|
|