refactor: improve readability of code

Signed-off-by: Aditya Agarwal <[email protected]>

src/main.cpp

@@ -6,22 +6,25 @@
 
 #include "constants.h"
 
+const int CROSSHAIR_LEFT = CROSSHAIR_W / 2;
+const int CROSSHAIR_RIGHT = DISPLAY_WIDTH - 1 - (CROSSHAIR_W / 2);
+const int CROSSHAIR_TOP = CROSSHAIR_H / 2;
+const int CROSSHAIR_BOTTOM = DISPLAY_HEIGHT - 1 - (CROSSHAIR_H / 2);
+
 const int crosshairCoors[][2] = {
-  {0 + (CROSSHAIR_W >> 1),                  0 + (CROSSHAIR_H >> 1)},
-  {DISPLAY_WIDTH - 1 - (CROSSHAIR_W >> 1),  0 + (CROSSHAIR_W >> 1)},
-  {0 + (CROSSHAIR_W >> 1),                  DISPLAY_HEIGHT - 1 - (CROSSHAIR_H >> 1)},
-  {DISPLAY_WIDTH - 1 - (CROSSHAIR_W >> 1),  DISPLAY_HEIGHT - 1 - (CROSSHAIR_H >> 1)}
+  {CROSSHAIR_LEFT, CROSSHAIR_TOP},
+  {CROSSHAIR_RIGHT, CROSSHAIR_TOP},
+  {CROSSHAIR_LEFT, CROSSHAIR_BOTTOM},
+  {CROSSHAIR_RIGHT, CROSSHAIR_BOTTOM},
 };
 
 const int NUM_CROSSHAIRS = sizeof(crosshairCoors) / sizeof(crosshairCoors[0]);
 
 MCUFRIEND_kbv tft;
 
 TouchScreen ts(XP, YP, XM, YM, 300);
-TSPoint p;
 
-void
-draw_crosshair(uint16_t x, uint16_t y, uint16_t clr) {
+void draw_crosshair(uint16_t x, uint16_t y, uint16_t clr) {
 
   const int x1 = x - (CROSSHAIR_W >> 1);
   const int x2 = x + (CROSSHAIR_W >> 1);
@@ -35,39 +38,42 @@ draw_crosshair(uint16_t x, uint16_t y, uint16_t clr) {
   tft.drawLine(x1, y2, x2, y1, clr);
 }
 
-void
-toDisplayMode() {
+void to_display_mode() {
 
   pinMode(XM, OUTPUT);
   pinMode(XP, OUTPUT);
   pinMode(YM, OUTPUT);
   pinMode(YP, OUTPUT);
 }
 
-bool
-valid_touch() {
+bool valid_touch() {
 
-  p = ts.getPoint();
-  if (p.z > PRESSURE_RIGHT || p.z < PRESSURE_LEFT) {
-    return false;
-  }
+  TSPoint p = ts.getPoint();
+  to_display_mode();
 
-  return true;
+  return (PRESSURE_LEFT <= p.z) && (p.z <= PRESSURE_RIGHT);
 }
 
-void
-get_touch(uint16_t *xptr, uint16_t *yptr) {
+void get_touch(uint16_t *xptr, uint16_t *yptr) {
+
+  TSPoint p;
 
-  while (!valid_touch());
+  while (1) {
+    p = ts.getPoint();
+    if ((PRESSURE_LEFT <= p.z) && (p.z <= PRESSURE_RIGHT)) {
+      break;
+    }
+  }
 
   *xptr = p.x;
   *yptr = p.y;
+
+  to_display_mode();
 }
 
-void
-setup() {
+void setup() {
 
-  uint16_t touchCoors[NUM_CROSSHAIRS][2];
+  uint16_t touch_coors[NUM_CROSSHAIRS][2];
 
   uint16_t xbeginf = 0;
   uint16_t xendf   = 0;
@@ -95,25 +101,22 @@ setup() {
     uint16_t tx;
     uint16_t ty;
 
-    for (int _ = 0; _ < CALIBRATION_TOUCH_CNT; ++_) {
+    for (uint16_t _ = 0; _ < CALIBRATION_TOUCH_CNT; ++_) {
 
-      toDisplayMode();
       draw_crosshair(cx, cy, RED);
 
       get_touch(&tx, &ty);
       ax += tx;
       ay += ty;
 
-      toDisplayMode();
       draw_crosshair(cx, cy, GREEN);
 
       delay(CALIBRATION_TOUCH_PERIOD_MS);
     }
 
-    touchCoors[i][0] = ax / CALIBRATION_TOUCH_CNT;
-    touchCoors[i][1] = ay / CALIBRATION_TOUCH_CNT;
+    touch_coors[i][0] = ax / CALIBRATION_TOUCH_CNT;
+    touch_coors[i][1] = ay / CALIBRATION_TOUCH_CNT;
 
-    toDisplayMode();
     draw_crosshair(cx, cy, WHITE);
 
     while (valid_touch());
@@ -125,8 +128,8 @@ setup() {
     uint16_t cx = crosshairCoors[i][0];
     uint16_t cy = crosshairCoors[i][1];
 
-    uint16_t tx = touchCoors[i][0];
-    uint16_t ty = touchCoors[i][1];
+    uint16_t tx = touch_coors[i][0];
+    uint16_t ty = touch_coors[i][1];
 
     if (cx == (CROSSHAIR_W >> 1)) {
       xbeginf += tx;
@@ -162,7 +165,7 @@ setup() {
   Serial.print("const int YBEGIN = "); Serial.println(ybegin);
   Serial.print("const int YEND = "); Serial.println(yend);
 
-  toDisplayMode();
+  to_display_mode();
 
   tft.setTextSize(2);
   tft.setTextColor(WHITE);
@@ -181,6 +184,5 @@ setup() {
   tft.println(yend);
 }
 
-void
-loop() {
+void loop() {
 }