From 564d05b183ac03cd7492807191dbd78d117895be Mon Sep 17 00:00:00 2001
From: Andy Killorin <37423245+Speedy6451@users.noreply.github.com>
Date: Sat, 12 Apr 2025 17:25:21 -0400
Subject: [PATCH] implemented graphics

---
 main.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)

diff --git a/main.c b/main.c
index f389e6e..0c8fe10 100644
--- a/main.c
+++ b/main.c
@@ -34,6 +34,8 @@
 
 uint32_t gSystemClock = 120000000; // [Hz] system clock frequency
 
+tContext sContext;
+
 #define LOCAL_BUF_LEN 128
 uint16_t adc_buffer_sample[LOCAL_BUF_LEN]; // copy of g adc buffer
 uint8_t adc_buffer_processed[LOCAL_BUF_LEN]; // copy of g adc buffer
@@ -109,6 +111,12 @@ int main(void)
     start_signal();
     start_sampler();
 
+    Crystalfontz128x128_Init(); // Initialize the LCD display driver
+    Crystalfontz128x128_SetOrientation(LCD_ORIENTATION_UP); // set screen orientation
+
+    GrContextInit(&sContext, &g_sCrystalfontz128x128); // Initialize the grlib graphics context
+    GrContextFontSet(&sContext, &g_sFontFixed6x8); // select font
+
     /* Start BIOS */
     BIOS_start();
 
@@ -171,8 +179,73 @@ void process_waveform(UArg arg1, UArg arg2) {
 
 void display_waveform(UArg arg1, UArg arg2)
 {
+    char str[50];   // string buffer
+    tRectangle rectFullScreen = {0, 0, GrContextDpyWidthGet(&sContext)-1, GrContextDpyHeightGet(&sContext)-1};
+
     while(1) {
         Semaphore_pend(display_sem, BIOS_WAIT_FOREVER);
+
+        GrContextForegroundSet(&sContext, ClrBlack);
+        GrRectFill(&sContext, &rectFullScreen); // fill screen with black
+
+        GrContextForegroundSet(&sContext, ClrBlue);
+
+        // draw gridlines from the center out
+        uint8_t xy_pos;
+        for (xy_pos = HEIGHT/2; xy_pos < HEIGHT; xy_pos += PIXELS_PER_DIV) {
+            GrLineDrawV(&sContext, xy_pos, 0, 128); // right
+            GrLineDrawV(&sContext, HEIGHT - xy_pos, 0, 128); // left
+
+            GrLineDrawH(&sContext, 0, 128, xy_pos); // down
+            GrLineDrawH(&sContext, 0, 128, HEIGHT - xy_pos); // up
+        }
+
+
+        // info
+        GrContextForegroundSet(&sContext, ClrWheat);
+        GrStringDraw(&sContext, gVoltageScaleStr[voltage_scale], /*length*/ -1, /*x*/ 0, /*y*/ 0, /*opaque*/ false);
+        GrStringDraw(&sContext, gTimeScaleStr[time_scale], /*length*/ -1, /*x*/ 60, /*y*/ 0, /*opaque*/ false);
+        //snprintf(str, sizeof(str), "CPU Load %.1f%%", usage_percent);
+        //GrStringDraw(&sContext, str, /*length*/ -1, /*x*/ 0, /*y*/ HEIGHT - 10, /*opaque*/ false);
+
+        switch (trigger_mode) {
+            case 1:
+                GrStringDraw(&sContext, "^", /*length*/ -1, /*x*/ WIDTH - 10, /*y*/ 0, /*opaque*/ false);
+                break;
+            case 0:
+                GrStringDraw(&sContext, "v", /*length*/ -1, /*x*/ WIDTH - 10, /*y*/ 0, /*opaque*/ false);
+                break;
+            case 2:
+                GrStringDraw(&sContext, "-", /*length*/ -1, /*x*/ WIDTH - 10, /*y*/ 0, /*opaque*/ false);
+                break;
+        }
+
+        // display graph
+        GrContextForegroundSet(&sContext, ClrYellow);
+        int j;
+        for(j=0; j<LOCAL_BUF_LEN; j++) {
+            #define MIN(a,b) (((a)<(b))?(a):(b))
+            #define MAX(a,b) (((a)>(b))?(a):(b))
+            uint32_t upper,lower, current, last;
+
+            if (j==0) {
+                upper = adc_buffer_processed[j];
+                lower = upper;
+                last = upper;
+            } else {
+                current = adc_buffer_processed[j];
+
+                upper = MAX(current, last);
+                lower = MIN(current, last);
+
+                last = current;
+            }
+
+            GrLineDrawV(&sContext, j, lower, upper);
+        }
+
+        GrFlush(&sContext); // flush the frame buffer to the LCD
+
     }
 }