1 files changed, 155 insertions, 0 deletions
diff --git a/src/gl/data.c b/src/gl/data.c
new file mode 100644
index 0000000..f598784
--- /dev/null
+++ b/src/gl/data.c
@@ -0,0 +1,155 @@
+#include <stdlib.h>
+#include <stdbool.h>
+#include "gl/glad/glad.h"
+#include <GLFW/glfw3.h>
+#include <lua.h>
+#include <honeysuckle.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)
+{
+	int buffer_binding_targets = hs_create_table(L,
+		hs_str_int("arrayBuffer", GL_ARRAY_BUFFER),
+		hs_str_int("elementArrayBuffer", GL_ELEMENT_ARRAY_BUFFER),
+	);
+
+	int buffer_usage_patterns = hs_create_table(L,
+		hs_str_int("streamDraw", GL_STREAM_DRAW),
+		hs_str_int("staticDraw", GL_STATIC_DRAW),
+		hs_str_int("dynamicDraw", GL_DYNAMIC_DRAW),
+	);
+
+	hs_create_table(L,
+		hs_str_cfunc("createBuffer", gl_create_buffer),
+		hs_str_cfunc("bindBuffer", gl_bind_buffer),
+		hs_str_cfunc("bufferData", gl_buffer_data),
+
+		hs_str_cfunc("createVertexArray", gl_vertex_array_create),
+		hs_str_cfunc("bindVertexArray", gl_vertex_array_bind),
+		hs_str_cfunc("vertexAttribPointer", gl_vertex_attrib_pointer),
+		hs_str_cfunc("vertexArrayEnableAttrib", gl_vertex_array_enable_attrib),
+
+		hs_str_tbl("bufferTarget", buffer_binding_targets),
+		hs_str_tbl("bufferUsage", buffer_usage_patterns),
+	);	
+
+	lua_setfield(L, gl_index, "data");
+}
+
+
+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)
+{
+	lua_Integer target, buf;
+	hs_parse_args(L, hs_int(target), hs_int(buf));
+	glBindBuffer(target, buf);
+	return 0;
+}
+
+
+int gl_buffer_data(lua_State *L)
+{
+	lua_Integer target, type, usage;
+	int table;
+	hs_parse_args(L, hs_int(target), hs_int(type), hs_tbl(table), hs_int(usage));
+
+	if (type != GL_INT && type != GL_FLOAT) {
+		hs_throw_error(L, "invalid type");
+	}
+
+	/* build raw buffer */
+	size_t len = lua_objlen(L, table);
+	void *buf;
+	if (type == GL_FLOAT) {
+		float *fbuf = malloc(len * sizeof(float));
+		if (fbuf == NULL)
+			hs_throw_error(L, "failed to allocate intermediary fbuffer");
+		for (int i=0; i<len; i++) {
+			lua_rawgeti(L, table, i+1);
+			if (!lua_isnumber(L, -1)) {
+				hs_throw_error(L, "all table items must be numbers (failed at index %d)", i);
+			}
+			fbuf[i] = lua_tonumber(L, -1);
+			lua_pop(L, 1);
+		}
+		len = len * sizeof(float);
+		buf = fbuf;
+	}
+	else {
+		int *ibuf = malloc(len * sizeof(int));
+		if (ibuf == NULL)
+			hs_throw_error(L, "failed to allocate intermediary ibuffer");
+		for (int i=0; i<len; i++) {
+			lua_rawgeti(L, table, i+1);
+			if (!lua_isnumber(L, -1)) {
+				hs_throw_error(L, "all table items must be integers (failed at index %d)", i);
+			}
+			ibuf[i] = lua_tointeger(L, -1);
+			lua_pop(L, 1);
+		}
+		len = len * sizeof(int);
+		buf = ibuf;
+	}
+
+	/* 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;
+	hs_parse_args(L, hs_int(array));
+	glBindVertexArray(array);
+	return 0;
+}
+
+
+int gl_vertex_attrib_pointer(lua_State *L)
+{
+	lua_Integer index, size, stride, offset;
+	bool normalized;
+	hs_parse_args(L, hs_int(index), hs_int(size), hs_bool(normalized), hs_int(stride), hs_int(offset));
+	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;
+	hs_parse_args(L, hs_int(index));
+	glEnableVertexAttribArray(index);
+	return 0;
+}