Added graphics.h header file for 2D graphics. Also since it adds a lot, i had to increase kernel size from 10kB to 15kB

include/graphics.h

@@ -0,0 +1,133 @@
+#ifndef GRAPHICS_H
+#define GRAPHICS_H
+
+#include "stdint.h"
+#include "screen.h"
+#include "math.h"
+
+// Basic full saturation colors
+#define BLACK   0x00000000 // 0
+#define RED     0x00ff0000 // 1
+#define GREEN   0x0000ff00 // 2
+#define YELLOW  0x00ffff00 // 3
+#define BLUE    0x000000ff // 4
+#define MAGENTA 0x00ff00ff // 5
+#define CYAN    0x0000ffff // 6
+#define WHITE   0x00ffffff // 7
+
+#define rgb(r,g,b) ( ((r) << 16 | (g) << 8 | (b)) & 0x00ffffff )
+
+void drawPixel(int32_t x, int32_t y, uint32_t color) {
+    uint32_t offset = (y * WIDTH) + x;
+    vidmem[offset] = color;
+}
+
+// Source: https://en.wikipedia.org/wiki/Bresenham's_line_algorithm
+void drawLine(int32_t x1, int32_t y1, int32_t x2, int32_t y2, uint32_t color) {
+    int32_t dx = abs(x2 - x1);
+    int32_t dy = -abs(y2 - y1);
+    int8_t sx = (x1 < x2) ? 1 : -1;
+    int8_t sy = (y1 < y2) ? 1 : -1;
+    int16_t err = dx + dy;
+    
+    // TODO: Sometimes the condition isn't met for some reason and it breaks everything
+    while (!(x1 == x2 && y1 == y2)) {
+        drawPixel(x1, y1, color);
+
+        if (err * 2 >= dy) {
+            err += dy;
+            x1 += sx;
+        }
+        if (err * 2 <= dx) {
+            err += dx;
+            y1 += sy;
+        }
+    }
+}
+
+void drawRect(int32_t x1, int32_t y1, int32_t x2, int32_t y2, uint32_t color) {
+    drawLine(x1, y1, x2, y1, color);
+    drawLine(x2, y1, x2, y2, color);
+    drawLine(x2, y2, x1, y2, color);
+    drawLine(x1, y2, x1, y1, color);
+}
+
+void drawTriangle(int32_t x1, int32_t y1, int32_t x2, int32_t y2, int32_t x3, int32_t y3, uint32_t color) {
+    drawLine(x1, y1, x2, y2, color);
+    drawLine(x2, y2, x3, y3, color);
+    drawLine(x3, y3, x1, y1, color);
+}
+
+void drawCircle(int32_t x, int32_t y, uint16_t radius, uint32_t color) {
+    int16_t offX = 0;
+    int16_t offY = radius;
+    int16_t p = 1 - radius;
+
+    // Draw 8 octant points
+    drawPixel(x + offX, y + offY, color);
+    drawPixel(x - offX, y + offY, color);
+    drawPixel(x + offX, y - offY, color);
+    drawPixel(x - offX, y - offY, color);
+    drawPixel(x + offY, y + offX, color);
+    drawPixel(x - offY, y + offX, color);
+    drawPixel(x + offY, y - offX, color);
+    drawPixel(x - offY, y - offX, color);
+
+    while (offX < offY) {
+        offX++;
+        if (p < 0) p += 2 * offX + 1;
+        else {
+            offY--;
+            p += 2 * (offX - offY) + 1;
+        }
+        
+        drawPixel(x + offX, y + offY, color);
+        drawPixel(x - offX, y + offY, color);
+        drawPixel(x + offX, y - offY, color);
+        drawPixel(x - offX, y - offY, color);
+        drawPixel(x + offY, y + offX, color);
+        drawPixel(x - offY, y + offX, color);
+        drawPixel(x + offY, y - offX, color);
+        drawPixel(x - offY, y - offX, color);
+    }
+}
+
+// Recursive (may need large stack)
+void boundaryFill(int32_t x, int32_t y, uint32_t fillColor, uint32_t boundaryColor) {
+    uint32_t offset = y * WIDTH + x;
+
+    if (vidmem[offset] != fillColor && vidmem[offset] != boundaryColor) {
+        vidmem[offset] = fillColor;
+
+        boundaryFill(x + 1, y, fillColor, boundaryColor);
+        boundaryFill(x - 1, y, fillColor, boundaryColor);
+        boundaryFill(x, y + 1, fillColor, boundaryColor);
+        boundaryFill(x, y - 1, fillColor, boundaryColor);
+    }
+}
+
+void fillRect(int32_t x1, int32_t y1, int32_t x2, int32_t y2, uint32_t color) {
+    int32_t cx = (x1 + x2) / 2;
+    int32_t cy = (y1 + y2) / 2;
+
+    drawRect(x1, y1, x2, y2, color - 1);
+    boundaryFill(cx, cy, color, color - 1);
+    drawRect(x1, y1, x2, y2, color);
+}
+
+void fillTriangle(int32_t x1, int32_t y1, int32_t x2, int32_t y2, int32_t x3, int32_t y3, uint32_t color) {
+    int32_t cx = (x1 + x2 + x3) / 3;
+    int32_t cy = (y1 + y2 + y3) / 3;
+
+    drawTriangle(x1, y1, x2, y2, x3, y3, color - 1);
+    boundaryFill(cx, cy, color, color - 1);
+    drawTriangle(x1, y1, x2, y2, x3, y3, color);
+}
+
+void fillCircle(int32_t x, int32_t y, uint16_t radius, uint32_t color) {
+    drawCircle(x, y, radius, color - 1);
+    boundaryFill(x, y, color, color - 1);
+    drawCircle(x, y, radius, color);
+}
+
+#endif

include/math.h

@@ -0,0 +1,8 @@
+#ifndef MATH_H
+#define MATH_H
+
+#define abs(x) ( (x) > 0 ? (x) : -(x) )
+#define sign(x) ( (x) == 0 ? 0 : ((x) < 0 ? -1 : 1 ) )
+#define round(x) ( (int)((x) + 0.5) )
+
+#endif