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

Makefile

@@ -13,13 +13,17 @@ BUILD = ./build
 
 # Main compilation target
 os: $(BUILD) bootloader kernel
-	@$(AS) -fbin -o $(BUILD)/filetable.bin $(SRC)/filetable.asm
+	@echo "Assembling $(SRC)/testfont.asm..."
 	@$(AS) -fbin -o $(BUILD)/testfont.bin $(SRC)/testfont.asm
+	@echo "Building filesystem..."
+	@$(AS) -fbin -o $(BUILD)/filetable.bin $(SRC)/filetable.asm
 	@cat $(BUILD)/boot.bin $(BUILD)/filetable.bin $(BUILD)/kernel.bin > $(BUILD)/os.bin
-	@dd if=/dev/zero of=kern.iso bs=512 count=2880
+	@echo "Building kern.iso..."
-	@dd if=$(BUILD)/os.bin of=kern.iso conv=notrunc
+	@dd if=/dev/zero of=kern.iso bs=512 count=2880 status=none
-	@dd if=$(BUILD)/testfont.bin of=kern.iso bs=512 seek=25 conv=notrunc
+	@dd if=$(BUILD)/os.bin of=kern.iso conv=notrunc status=none
-	@dd if=$(SRC)/fs/test.txt of=kern.iso bs=512 seek=29 conv=notrunc
+	@dd if=$(BUILD)/testfont.bin of=kern.iso bs=512 seek=35 conv=notrunc status=none
+	@dd if=$(SRC)/fs/test.txt of=kern.iso bs=512 seek=39 conv=notrunc status=none
+	@echo "\nDone!\n"
 
 $(BUILD):
 	@[ -d $(BUILD) ] || mkdir $(BUILD)
@@ -27,13 +31,17 @@ $(BUILD):
 
 # Bootloader: This target is responsible for creating boot.bin
 bootloader:
+	@echo "Assembling $(SRC)/stage1.asm..."
 	@$(AS) -fbin -o $(BUILD)/stage1.bin $(SRC)/stage1.asm
+	@echo "Assembling $(SRC)/stage2.asm..."
 	@$(AS) -fbin -o $(BUILD)/stage2.bin $(SRC)/stage2.asm
 	@cat $(BUILD)/stage1.bin $(BUILD)/stage2.bin > $(BUILD)/boot.bin
 
 # Kernel: This target is responsible for creating kernel.bin
 kernel: $(SRC)/kernel.c $(SRC)/entry.asm
+	@echo "Assembling $(SRC)/entry.asm..."
 	@$(AS) -felf32 -o $(BUILD)/entry.o $(SRC)/entry.asm
+	@echo "Compiling $(SRC)/kernel.c..."
 	@$(CC) $(CFLAGS) -o $(BUILD)/kernel.o -c $(SRC)/kernel.c
 	@$(LD) -T $(SRC)/kernel.ld --oformat binary -o $(BUILD)/kernel.bin $(BUILD)/*.o
 

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

src/filetable.asm

@@ -12,9 +12,9 @@
 filetable:
     db "boot",0,0,0,0,0,0, "bin",0,0,4
     db "filetable",0,      "tab",0,4,1
-    db "kernel",0,0,0,0,   "bin",0,5,20
+    db "kernel",0,0,0,0,   "bin",0,5,30
-    db "testfont",0,0,     "fnt",0,25,4
+    db "testfont",0,0,     "fnt",0,35,4
-    db "test",0,0,0,0,0,0, "txt",0,29,1
+    db "test",0,0,0,0,0,0, "txt",0,39,1
 
 times 512-($-$$) db 0
 

src/kernel.c

@@ -7,6 +7,7 @@
 #include "system.h"
 #include "disk.h"
 #include "string.h"
+#include "graphics.h"
 
 #define PROMPT "#> "
 
@@ -25,7 +26,8 @@ void main() {
     timerPhase(1000); // 1 tick per ~1ms
 
     // Screen setup
-    diskRead(25, 4, (char*)0x6000); // Read font from disk
+    // TODO: Find font in filetable
+    diskRead(35, 4, (char*)0x6000); // Read font from disk
     setupScreen();
     loadFont((char*)0x6000);
 
@@ -112,12 +114,46 @@ void main() {
             print(args);
         } else if (strcmp(input, "exit") == 0) {
             break;
+        } else if (strcmp(input, "gfx") == 0) {
+            clear();
+
+            // Draw some stuff :)
+            for (size_t i = 0; i < 120; i++) {
+                for (size_t j = 0; j < 120; j++) {
+                    drawPixel(200 + i, 200 + j, GREEN);
+                } 
+            }
+
+            fillRect(200, 200, 320, 320, GREEN);
+
+            drawLine(200, 200, 320, 320, RED);
+            drawLine(320, 200, 200, 320, RED);
+
+            drawLine(800, 300, 900, 400, BLUE);
+            drawLine(900, 400, 1000, 300, BLUE);
+            drawLine(1000, 300, 900, 200, BLUE);
+            drawLine(900, 200, 800, 300, BLUE);
+
+            drawLine(400, 350, 420, 100, rgb(0xee, 0x9f, 0x00));
+
+            drawTriangle(200, 400, 400, 600, 200, 600, MAGENTA);
+            fillTriangle(750, 400, 800, 450, 700, 450, CYAN);
+            drawTriangle(960, 400, 1000, 500, 990, 580, YELLOW);
+
+            drawRect(100, 650, 800, 900, rgb(0xe0, 0x0a, 0x3a));
+
+            drawCircle(1500, 600, 300, WHITE);
+            fillCircle(950, 750, 75, rgb(0xa2, 0xd6, 0xf9));
+
+            read('q'); // Wait until we get a 'q'
+            clear();
         } else if (strcmp(input, "help") == 0) {
             print("Available Commands:\n");
             print(" clear      | Clears the screen\n");
             print(" disk       | Reads/Writes data from/to the disk\n");
             print(" echo       | Prints a message to stdout\n");
             print(" exit       | Exits shell\n");
+            print(" gfx        | Does a graphics test\n");
             print(" help       | Prints this message\n");
             print(" ls         | Lists all available files\n");
             print(" reboot     | Reboots the system\n");

src/stage1.asm

@@ -4,7 +4,7 @@
 
 %define VIDMEM 0xb800
 %define KERNEL_LOC 0x1000
-%define KERNEL_SIZE 20 ; 10kB
+%define KERNEL_SIZE 30 ; 15kB
 
 start:
     mov [driveNum], dl   ; Store the drive number

todo.txt

@@ -1,6 +1,7 @@
 === Todo ===
 
 - [*] Multistage Bootloader
+- [ ] Bootloader reads filetable to find files
 - [ ] Write down where stuff is in memory (0x1000 - kernel, 0x4000? - filetable, 0x5000 - VBE Mode Info, 0x6000 - Font)
 - [ ] "Text" mode (not actually)
     - [ ] Scrolling
@@ -12,11 +13,15 @@
     - [*] Custom font
     - [*] Larger text size
     - [ ] Variable text size :)
+    - [ ] Make output overflow go to next line
 - [ ] Graphics
-    - [ ] Enter/exit a "graphics" mode
+    - [ ] Enter/exit a "graphics" mode (idk if we need this)
-    - [ ] Pixel drawing
+    - [x] Pixel drawing
-    - [ ] Line drawing (Raycaster Alert??)
+    - [x] Line drawing (Raycaster Alert??)
-    - [ ] Triangles (3D?!!???)
+    - [x] Triangles (3D?!!???)
+    - [x] Rectange :)
+    - [x] Circle!
+    - [x] Filled verisons
 - [ ] Math
     - [ ] Trigonometry
         - [ ] Sine
@@ -25,7 +30,7 @@
         - [ ] Cotangent
         - [ ] Arc (inverse) versions
         - [ ] Hyperbolic versions
-    - [ ] Absolute value
+    - [x] Absolute value
     - [ ] isOdd() 🗿
     - [ ] Exponential fn (e^x)
     - [ ] Logarithm
@@ -33,8 +38,9 @@
     - [ ] Square Root
     - [ ] Nth Root
     - [ ] Floor
-    - [ ] Round
+    - [x] Round
     - [ ] Ceiling
+    - [x] Sign
     - [ ] INFINITY
     - [ ] NAN
 - [ ] Filesystem