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#include "mesh.h"
static int honey_mesh_lua_draw(lua_State* L)
{
honey_mesh* mesh;
int shader;
honey_lua_parse_arguments(L, 2,
HONEY_USERDATA, &mesh,
HONEY_INTEGER, &shader);
honey_mesh_draw(*mesh, shader);
return 0;
}
static int honey_mesh_lua_delete(lua_State* L)
{
honey_mesh* mesh;
honey_lua_parse_arguments(L, 1, HONEY_USERDATA, &mesh);
honey_mesh_delete(*mesh);
return 0;
}
void honey_setup_mesh(lua_State* L)
{
honey_lua_element mesh_elements[] = {
{ "draw", HONEY_FUNCTION, { .function = honey_mesh_lua_draw } },
{ "delete", HONEY_FUNCTION, { .function = honey_mesh_lua_delete } },
};
honey_lua_create_table(L, mesh_elements, 2);
}
/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
honey_result honey_mesh_new(honey_mesh* mesh,
float* vertices,
unsigned int n_vertices,
unsigned int n_attributes,
unsigned int* attribute_sizes,
unsigned int* indices,
unsigned int n_indices) {
if (vertices == NULL || n_vertices == 0) {
return HONEY_MESH_BAD_VERTEX_DATA;
}
if (indices == NULL || n_indices == 0) {
return HONEY_MESH_BAD_INDEX_DATA;
}
unsigned int vertex_size = 0;
for (int i=0; i<n_attributes; i++) {
vertex_size += attribute_sizes[i];
}
(*mesh).n_vertices = n_vertices;
(*mesh).n_indices = n_indices;
glGenVertexArrays(1, &((*mesh).vertex_array));
glGenBuffers(1, &((*mesh).vertex_buffer));
glGenBuffers(1, &((*mesh).element_buffer));
glBindVertexArray((*mesh).vertex_array);
glBindBuffer(GL_ARRAY_BUFFER, (*mesh).vertex_buffer);
glBufferData(GL_ARRAY_BUFFER,
vertex_size * n_vertices * sizeof(float),
vertices, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, (*mesh).element_buffer);
glBufferData(GL_ELEMENT_ARRAY_BUFFER,
n_indices * sizeof(unsigned int),
indices, GL_STATIC_DRAW);
/* set up vertex attributes */
unsigned int offset = 0;
for (int i=0; i<n_attributes; i++) {
glEnableVertexAttribArray(i);
glVertexAttribPointer(i,
attribute_sizes[i],
GL_FLOAT,
GL_FALSE,
vertex_size*sizeof(float),
(void*) (offset*sizeof(float)));
offset += attribute_sizes[i];
}
glBindVertexArray(0);
return HONEY_OK;
}
/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
void honey_mesh_draw(honey_mesh mesh, int shader) {
glUseProgram(shader);
glBindVertexArray(mesh.vertex_array);
glDrawElements(GL_TRIANGLES, mesh.n_indices, GL_UNSIGNED_INT, 0);
glBindVertexArray(0);
}
/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
void honey_mesh_delete(honey_mesh mesh) {
glDeleteVertexArrays(1, &(mesh.vertex_array));
glDeleteBuffers(1, &(mesh.vertex_buffer));
glDeleteBuffers(1, &(mesh.element_buffer));
}
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