add line drawing, add triangles.c

1 files changed, 38 insertions, 0 deletions

diff --git a/examples/triangles.c b/examples/triangles.c
new file mode 100644
index 0000000..f995574
--- /dev/null
+++ b/examples/triangles.c
@@ -0,0 +1,38 @@
+#include "../sponge.h"
+
+#define SPEED_ABS (2)
+#define GRID_SIZE (10)
+
+
+static int32_t offset = 0;
+static int32_t speed = SPEED_ABS;
+
+void init() {}
+
+void draw_frame(sponge_Texture c) {
+    sponge_clear(c, 0xFF000000);
+    offset += speed;
+
+    if (offset > 30) {
+        speed = -SPEED_ABS;
+    } else if (offset < -30) {
+        speed = SPEED_ABS;
+    }
+
+    int32_t offset_x = c.width / GRID_SIZE;
+    int32_t offset_y = c.height / GRID_SIZE;
+
+    for (int i = 0; i < GRID_SIZE; i++) {
+        for (int j = 0; j < GRID_SIZE; j++) {
+            int32_t x = i * offset_x;
+            int32_t y = j * offset_y + offset;
+
+        sponge_draw_triangle_col3(
+            c,
+            x, y + offset_y,
+            x + offset_x, y,
+            x + (offset_x / 4), y + (offset_y / 4),
+            0xFFFF0000, 0xFF00FF00, 0xFF0000FF);
+        }
+    }
+}