add line drawing, add triangles.c

1 files changed, 25 insertions, 0 deletions

diff --git a/examples/line.c b/examples/line.c
new file mode 100644
index 0000000..31724a9
--- /dev/null
+++ b/examples/line.c
@@ -0,0 +1,25 @@
+#include <math.h>
+
+#include "../sponge.h"
+
+#define PI ((float)3.14159265358979323846)
+#define SPEED (0.5f / 360.0f * 2 * PI)
+static float angle = 0.0f;
+#define MIN(x, y) ((x) < (y) ? (x) : (y))
+
+void init() {}
+
+void draw_frame(sponge_Texture c) {
+    sponge_clear(c, 0xFF000000);
+    angle += SPEED;
+
+    float x = sinf(angle);
+    float y = cosf(angle);
+    int32_t half = (int32_t)MIN(c.width, c.height) / 2;
+
+    sponge_draw_line(
+        c,
+        half + (int32_t)( x * (float)half), half + (int32_t)( y * (float)half),
+        half + (int32_t)(-x * (float)half), half + (int32_t)(-y * (float)half),
+        0xFFFF00FF);
+}