add matrices (not tested enough)

1 files changed, 30 insertions, 0 deletions

diff --git a/examples/matrix.c b/examples/matrix.c
new file mode 100644
index 0000000..0b0ac91
--- /dev/null
+++ b/examples/matrix.c
@@ -0,0 +1,30 @@
+#include "../sponge.h"
+#define SPONGE_EXAMPLE_IMPLEMENTATION
+#include "../example.h"
+
+#define PI ((float)3.14159265358979323846)
+#define SPEED ((1.0f / 360.0f) * 2 * PI)
+static float angle = 0.0f;
+
+void draw_frame(sponge_Texture c) {
+    sponge_clear(c, sponge_color32_make(0xFF000000));
+    angle += SPEED;
+    sponge_Vec3 v0 = sponge_vec3_make(0.0f, -0.8f, 0.0f);
+    sponge_Vec3 v1 = sponge_vec3_make(0.8f, 0.8f, 0.0f);
+    sponge_Vec3 v2 = sponge_vec3_make(-0.8f, 0.8f, 0.0f);
+
+    sponge_Mat4 m = sponge_mat4_rotate(sponge_vec3_make(0.0f, 0.0f, angle));
+    m = sponge_mat4_mul_mat4(m, sponge_mat4_translate(sponge_vec3_make(1.0f, 1.0f, 0.0f)));
+    m = sponge_mat4_mul_mat4(m, sponge_mat4_scale(sponge_vec3_make((float)(c.width / 2), (float)(c.height / 2), 1.0f)));
+
+    v0 = sponge_vec3_mul_mat4(v0, m);
+    v1 = sponge_vec3_mul_mat4(v1, m);
+    v2 = sponge_vec3_mul_mat4(v2, m);
+
+    sponge_draw_triangle_col3(
+        c,
+        sponge_vec2i_make((int32_t)v0.x, (int32_t)v0.y),
+        sponge_vec2i_make((int32_t)v1.x, (int32_t)v1.y),
+        sponge_vec2i_make((int32_t)v2.x, (int32_t)v2.y),
+        sponge_colorf_make(0xFFFF0000), sponge_colorf_make(0xFF00FF00), sponge_colorf_make(0xFF0000FF));
+}