1 files changed, 44 insertions, 0 deletions

diff --git a/src/util/geometry.c b/src/util/geometry.c
new file mode 100644
index 0000000..afe0109
--- /dev/null
+++ b/src/util/geometry.c
@@ -0,0 +1,44 @@
+#include <gfx/util/geometry.h>
+
+#include <math/vec2.h>
+
+static void make_quad_11_positions(vec2 positions[4]) {
+  positions[0] = vec2_make(-1, +1);
+  positions[1] = vec2_make(-1, -1);
+  positions[2] = vec2_make(+1, +1);
+  positions[3] = vec2_make(+1, -1);
+}
+
+static void make_quad_01_positions(vec2 positions[4]) {
+  positions[0] = vec2_make(0, 0);
+  positions[1] = vec2_make(1, 0);
+  positions[2] = vec2_make(1, 1);
+  positions[3] = vec2_make(0, 1);
+}
+
+static GeometryDesc make_quad_desc(vec2 positions[4]) {
+  GeometryDesc desc           = (GeometryDesc){0};
+  desc.positions2d.data       = positions;
+  desc.positions2d.size_bytes = 4 * sizeof(vec2);
+  desc.num_verts              = 4;
+  desc.type                   = TriangleStrip;
+  return desc;
+}
+
+Geometry* gfx_make_quad_11(GfxCore* gfxcore) {
+  assert(gfxcore);
+
+  vec2 positions[4];
+  make_quad_11_positions(positions);
+  const GeometryDesc geometry_desc = make_quad_desc(positions);
+  return gfx_make_geometry(gfxcore, &geometry_desc);
+}
+
+Geometry* gfx_make_quad_01(GfxCore* gfxcore) {
+  assert(gfxcore);
+
+  vec2 positions[4];
+  make_quad_01_positions(positions);
+  const GeometryDesc geometry_desc = make_quad_desc(positions);
+  return gfx_make_geometry(gfxcore, &geometry_desc);
+}