From 21459ac4c92b82f2a3eeb1d9a6b462726001084c Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Tue, 18 Apr 2023 00:08:18 +0100
Subject: Specialize vertexAttribFunc for matrices because there's an upper
 limit of size 4 on attrib pointers

---
 lib/gl_traits.hpp | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

(limited to 'lib/gl_traits.hpp')

diff --git a/lib/gl_traits.hpp b/lib/gl_traits.hpp
index e2e689d..10b42e5 100644
--- a/lib/gl_traits.hpp
+++ b/lib/gl_traits.hpp
@@ -11,20 +11,23 @@ struct gl_traits_base {
 };
 struct gl_traits_float : public gl_traits_base {
 	static constexpr auto vertexAttribFunc {
-			[](GLuint index, GLint size, GLenum type, GLsizei stride, const void * pointer) {
+			[](GLuint index, GLint size, GLenum type, GLsizei stride, const void * pointer) -> GLuint {
 				glVertexAttribPointer(index, size, type, GL_FALSE, stride, pointer);
+				return 1;
 			}};
 };
 struct gl_traits_longfloat : public gl_traits_base {
 	static constexpr auto vertexAttribFunc {
-			[](GLuint index, GLint size, GLenum type, GLsizei stride, const void * pointer) {
+			[](GLuint index, GLint size, GLenum type, GLsizei stride, const void * pointer) -> GLuint {
 				glVertexAttribLPointer(index, size, type, stride, pointer);
+				return 1;
 			}};
 };
 struct gl_traits_integer : public gl_traits_base {
 	static constexpr auto vertexAttribFunc {
-			[](GLuint index, GLint size, GLenum type, GLsizei stride, const void * pointer) {
+			[](GLuint index, GLint size, GLenum type, GLsizei stride, const void * pointer) -> GLuint {
 				glVertexAttribIPointer(index, size, type, stride, pointer);
+				return 1;
 			}};
 };
 template<> struct gl_traits<glm::f32> : public gl_traits_float {
@@ -63,4 +66,12 @@ template<glm::length_t L, typename T, glm::qualifier Q> struct gl_traits<glm::ve
 template<glm::length_t C, glm::length_t R, typename T, glm::qualifier Q>
 struct gl_traits<glm::mat<C, R, T, Q>> : public gl_traits<T> {
 	static constexpr GLint size {C * R};
+	static constexpr auto vertexAttribFunc {
+			[](GLuint index, GLint, GLenum type, GLsizei stride, const void * pointer) -> GLuint {
+				const auto m = static_cast<glm::mat<C, R, T, Q>>(pointer);
+				for (glm::length_t r = 0; r < R; r++) {
+					glVertexAttribPointer(index, C, type, GL_FALSE, stride, &m[r]);
+				}
+				return R;
+			}};
 };
-- 
cgit v1.2.3


From 4360094ff6e9f4d245f832c58f673ae4d1f75950 Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Wed, 19 Apr 2023 01:45:47 +0100
Subject: Fixup vertexAttribFunc for matrices

---
 lib/gl_traits.hpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

(limited to 'lib/gl_traits.hpp')

diff --git a/lib/gl_traits.hpp b/lib/gl_traits.hpp
index 10b42e5..6ff8905 100644
--- a/lib/gl_traits.hpp
+++ b/lib/gl_traits.hpp
@@ -68,9 +68,9 @@ struct gl_traits<glm::mat<C, R, T, Q>> : public gl_traits<T> {
 	static constexpr GLint size {C * R};
 	static constexpr auto vertexAttribFunc {
 			[](GLuint index, GLint, GLenum type, GLsizei stride, const void * pointer) -> GLuint {
-				const auto m = static_cast<glm::mat<C, R, T, Q>>(pointer);
-				for (glm::length_t r = 0; r < R; r++) {
-					glVertexAttribPointer(index, C, type, GL_FALSE, stride, &m[r]);
+				const auto base = static_cast<const T *>(pointer);
+				for (GLuint r = 0; r < R; r++) {
+					glVertexAttribPointer(index + r, C, type, GL_FALSE, stride, base + (r * C));
 				}
 				return R;
 			}};
-- 
cgit v1.2.3