1 files changed, 164 insertions, 0 deletions
diff --git a/src/opengl/data.c b/src/opengl/data.c
new file mode 100644
index 0000000..b7dc581
--- /dev/null
+++ b/src/opengl/data.c
@@ -0,0 +1,164 @@
+#include <stdlib.h>
+#include <stdbool.h>
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include <lua.h>
+#include <lauxlib.h>
+#include "util/util.h"
+#include "gl.h"
+
+int gl_create_buffer(lua_State *L);
+int gl_bind_buffer(lua_State *L);
+int gl_buffer_data(lua_State *L);
+
+int gl_vertex_array_create(lua_State *L);
+int gl_vertex_array_bind(lua_State *L);
+int gl_vertex_attrib_pointer(lua_State *L);
+int gl_vertex_array_enable_attrib(lua_State *L);
+
+
+void setup_data(lua_State *L, int gl_index)
+{
+	struct honey_tbl_t tbl[] = {
+		/* functions */
+		H_FUNC("GenBuffers", gl_create_buffer),
+		H_FUNC("BindBuffer", gl_bind_buffer),
+		H_FUNC("BufferData", gl_buffer_data),
+
+		H_FUNC("GenVertexArrays", gl_vertex_array_create),
+		H_FUNC("BindVertexArray", gl_vertex_array_bind),
+		H_FUNC("VertexAttribPointer", gl_vertex_attrib_pointer),
+		H_FUNC("EnableVertexAttribArray", gl_vertex_array_enable_attrib),
+
+		/******** enums ********/
+		/* buffer bind targets */
+		H_INT("ARRAY_BUFFER", GL_ARRAY_BUFFER),
+		H_INT("ELEMENT_ARRAY_BUFFER", GL_ELEMENT_ARRAY_BUFFER),
+
+		/* buffer usage patters */
+		H_INT("STREAM_DRAW", GL_STREAM_DRAW),
+		H_INT("STATIC_DRAW", GL_STATIC_DRAW),
+		H_INT("DYNAMIC_DRAW", GL_DYNAMIC_DRAW),
+
+		H_END
+	};	
+	create_table(L, tbl);
+	append_table(L, gl_index, lua_gettop(L));
+	lua_pop(L, 1);
+}
+
+
+int gl_create_buffer(lua_State *L)
+{
+	int buf;
+	glGenBuffers(1, &buf);
+	lua_pushinteger(L, buf);
+	return 1;
+}
+
+
+int gl_bind_buffer(lua_State *L)
+{
+	int target = luaL_checkinteger(L, 1);
+	int buf = luaL_checkinteger(L, 2);
+	glBindBuffer(target, buf);
+	return 0;
+}
+
+
+#define GET_BUFFER_TYPE(type, name, conversion) \
+	void * get_buffer_ ## name (lua_State *L, size_t *sz, int tbl) { \
+		size_t len = lua_objlen(L, tbl); \
+		*sz = len * sizeof(type); \
+		type *buf = malloc(*sz); \
+		if (buf == NULL) \
+			luaL_error(L, "failed to allocate intermediary buffer"); \
+		for (int i=0; i<len; i++) { \
+			lua_rawgeti(L, tbl, i+1); \
+			if (!lua_isnumber(L, -1)) \
+				luaL_error(L, "all elements must be numbers (failed at index %d)", i); \
+			buf[i] = conversion(L, -1); \
+			lua_pop(L, 1); \
+		} \
+		return buf; \
+	}
+
+GET_BUFFER_TYPE(unsigned int, uint, lua_tointeger)
+GET_BUFFER_TYPE(int, int, lua_tointeger)
+GET_BUFFER_TYPE(float, float, lua_tonumber)
+
+int gl_buffer_data(lua_State *L)
+{
+	lua_Integer target, type, usage;
+	target = luaL_checkinteger(L, 1);
+	type = luaL_checkinteger(L, 2);
+	luaL_checktype(L, 3, LUA_TTABLE);
+	int table = 3;
+	usage = luaL_checkinteger(L, 4);
+
+	/* build raw buffer */
+	void *buf; size_t len;
+	switch(type) {
+	case GL_UNSIGNED_INT:
+		buf = get_buffer_uint(L, &len, table);
+		break;
+
+	case GL_INT:
+		buf = get_buffer_int(L, &len, table);
+		break;
+
+	case GL_FLOAT:
+		buf = get_buffer_float(L, &len, table);
+		break;
+
+	default:
+		luaL_error(L, "invalid type");
+	}
+
+	/* call */
+	glBufferData(target, len, buf, usage);
+	free(buf);
+	return 0;
+}
+
+
+int gl_vertex_array_create(lua_State *L)
+{
+	int array;
+	glGenVertexArrays(1, &array);
+	lua_pushinteger(L, array);
+	return 1;
+}
+
+
+int gl_vertex_array_bind(lua_State *L)
+{
+	lua_Integer array = luaL_checkinteger(L, 1);
+	glBindVertexArray(array);
+	return 0;
+}
+
+
+int gl_vertex_attrib_pointer(lua_State *L)
+{
+	lua_Integer index, size, stride, offset;
+	bool normalized;
+	index = luaL_checkinteger(L, 1);
+	size = luaL_checkinteger(L, 2);
+	normalized = lua_toboolean(L, 3);
+	stride = luaL_checkinteger(L, 4);
+	offset = luaL_checkinteger(L, 5);
+
+	glVertexAttribPointer(index, size, GL_FLOAT, 
+	                      normalized, stride*sizeof(float), 
+	                      (void*) (offset*sizeof(float)));
+	return 0;
+}
+
+
+int gl_vertex_array_enable_attrib(lua_State *L)
+{
+	lua_Integer index = luaL_checkinteger(L, 1);
+	glEnableVertexAttribArray(index);
+	return 0;
+}