Some line drawing functions

src/kernel/boot/TEMP-test_scheduler.c

@@ -3,13 +3,19 @@
 #include <mittos/graphics.h>
 
 extern gfx_context *term_fb;
+extern gfx_context kernel_fb;
 
 void thread1()
 {
-    int a = 0;
+    int a = 1;
+    gfx_context *ctx = framebuffer_make_subcontext(&kernel_fb, 700, 300, 100, 100);
     while(1) {
         putCharacter(term_fb, 0, 0, RGB(255,255,0), RGB(0,0,0), '0'+(a++%10));
         flip(term_fb);
+        draw_line(ctx, 0, 100, 50, ((a-1)%100), RGB(0,0,0));
+        draw_line(ctx, 0, 100, 50, (a%100), RGB(255,0,0));
+        flip(ctx);
+
         sched_yield();
     }
 }
@@ -19,8 +25,10 @@ void thread2()
     int a = 0;
     while(1) {
         putCharacter(term_fb, 10, 10, RGB(0,255,255), RGB(0,0,0), 'A'+(a++%10));
+        draw_rect(term_fb, 10, 10, 200, 300, RGB((uint8_t)(a%256), 0, 255-(uint8_t)(a%256)));
         flip(term_fb);
         sched_yield();
+        
     }
 }
 

src/kernel/drivers/terminal/fbterm.c

@@ -60,4 +60,11 @@ void fbterm_init(struct fbinfo *fbinfo)
     flip(term_fb);
     term_fb = framebuffer_make_subcontext(&kernel_fb, 24, 24, 8*VGA_COLS, 16*VGA_ROWS);
     setup = 1;
+
+    draw_line(&kernel_fb, 750, 850, 120, 120, RGB(255,0,0));
+    draw_line(&kernel_fb, 750, 750, 120, 220, RGB(0,255,0));
+    draw_line(&kernel_fb, 750, 850, 120, 220, RGB(0,0,255));
+    draw_line(&kernel_fb, 750, 800, 120, 220, RGB(255,0,255));
+    draw_line(&kernel_fb, 750, 850, 120, 170, RGB(255,255,0));
+    flip(&kernel_fb);
 }

src/libmittos/graphics/graphics.c

@@ -17,6 +17,43 @@ void putpixel(gfx_context *ctx, uint64_t x, uint64_t y, uint32_t clr)
     *fb = clr;
 }
 
+void draw_line(gfx_context *ctx, uint64_t x0, uint64_t x1, uint64_t y0, uint64_t y1, uint32_t clr)
+{
+    int64_t dx = x1 > x0 ? x1 - x0 : x0 - x1;
+    int64_t dy = y1 > y0 ? y1 - y0 : y0 - y1;
+    int sx = x1 > x0 ? 1 : -1;
+    int sy = y1 > y0 ? 1 : -1;
+    uint64_t x = x0, y = y0;
+    int64_t diff = dx - dy;
+    while(1)
+    {
+        putpixel(ctx, x, y, clr);
+        if(x == x1 && y == y1) break;
+        
+        if((2*diff) > -dy) {
+            diff -= dy;
+            x += sx;
+        } else {
+            diff += dx;
+            y += sy;
+        }
+    }
+}
+
+void draw_rect(gfx_context *ctx, uint64_t x, uint64_t y, uint64_t width, uint64_t height, uint32_t clr)
+{
+    for(uint64_t _x = x; _x <= x+width; _x++)
+    {
+        putpixel(ctx, _x, y, clr);
+        putpixel(ctx, _x, y+height, clr);
+    }
+    for(uint64_t _y = y; _y <= y+height; _y++)
+    {
+        putpixel(ctx, x, _y, clr);
+        putpixel(ctx, x+width, _y, clr);
+    }
+}
+
 void putCharacter(gfx_context *ctx, uint64_t x, uint64_t y, uint32_t clr_fg, uint32_t clr_bg, char c)
 {
 

src/libmittos/include/graphics.h

@@ -14,6 +14,8 @@ typedef struct {
 #define RGB(r, g, b) (((uint32_t) (r<<16) + (g<<8) + (b)))
 
 void putpixel(gfx_context *ctx, uint64_t x, uint64_t y, uint32_t clr);
+void draw_line(gfx_context *ctx, uint64_t x0, uint64_t x1, uint64_t y0, uint64_t y1, uint32_t clr);
+void draw_rect(gfx_context *ctx, uint64_t x, uint64_t y, uint64_t width, uint64_t height, uint32_t clr);
 void putCharacter(gfx_context *ctx, uint64_t x, uint64_t y, uint32_t clr_fg, uint32_t clr_bg, char c);
 void flip(gfx_context *ctx);
 gfx_context *framebuffer_make_subcontext(gfx_context *ctx, uint64_t x, uint64_t y, uint64_t width, uint64_t height);