quads

1 files changed, 43 insertions, 0 deletions

diff --git a/src/rendering.h b/src/rendering.h
index 67f4682..45a65c4 100644
--- a/src/rendering.h
+++ b/src/rendering.h
@@ -6,6 +6,49 @@
 #include "glad.h"
 #include "utils.h"
 
+struct quad_s {
+  vec2 vertices[WAYC_QUAD_NVERTS];
+  u32 indices[WAYC_QUAD_NINDICES];
+};
+
+static inline void wayc_quad_init(quad_s* quad, f32 left, f32 top, f32 right,
+                                  f32 bottom) {
+  wayc_notnull(quad);
+
+  /*
+    0 ---- 1
+    |      |
+    |      |
+    3 ---- 2
+  */
+
+  // Vertices (CCW order)
+  WAYC_X(quad->vertices[0]) = left;
+  WAYC_Y(quad->vertices[0]) = top;
+
+  WAYC_X(quad->vertices[1]) = right;
+  WAYC_Y(quad->vertices[1]) = top;
+
+  WAYC_X(quad->vertices[2]) = right;
+  WAYC_Y(quad->vertices[2]) = bottom;
+
+  WAYC_X(quad->vertices[3]) = left;
+  WAYC_Y(quad->vertices[3]) = bottom;
+
+  /*
+    Triangles (CCW):
+    0 1 2
+    0 2 3
+  */
+
+  quad->indices[0] = 0;
+  quad->indices[1] = 1;
+  quad->indices[2] = 2;
+  quad->indices[3] = 0;
+  quad->indices[4] = 2;
+  quad->indices[5] = 3;
+}
+
 // TODO: review all structs and use types
 
 enum image_type_e {