feat: add draw functions

src/draw.c

@@ -0,0 +1,54 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "draw.h"
+#include "math/vec4.h"
+
+char* canvas; 
+
+void initCanvas(int width, int height)
+{
+    int size = width*height;
+    canvas = malloc(size);
+    if (!canvas) exit(1);
+    memset(canvas, ' ', size);
+}
+
+void editCanvas(int width, int height)
+{
+    int size = width * height;
+    canvas = realloc(canvas, size);
+    if (!canvas) exit(1);
+}
+
+static char drawPixel(float zBuffer)
+{
+    if (zBuffer < 0.25f) return '.';
+    else if (zBuffer < 0.5f) return '*';
+    else if (zBuffer < 0.75f) return 'o';
+    else return '#';
+}
+
+void drawCanvas(Vec4f_t p, int width, int height)
+{
+    int x = (int)p.x;
+    int y = (int)p.y;
+    if(x >= 0 && x < width && y >= 0 && y < height)
+        canvas[y*width + x] = drawPixel(p.z);
+}
+
+void renderCanvas(int width, int height)
+{
+    for (int i = 0; i<height; i++) {
+        for (int j = 0; j<width; j++) {
+            putchar(canvas[i*width+j]);
+        }
+        putchar('\n');
+    }
+}
+
+void freeCanvas(void)
+{
+    free(canvas);
+}
+

src/draw.h

@@ -0,0 +1,12 @@
+#ifndef DRAW_H
+#define DRAW_H
+
+#include "math/vec4.h"
+
+void initCanvas(int width, int height);
+void editCanvas(int width, int height);
+void drawCanvas(Vec4f_t p, int width, int height);
+void renderCanvas(int width, int height);
+void freeCanvas(void);
+
+#endif // DRAW_H