Lumenarium/src_v2/lumenarium_geometry.h

314 lines
9.2 KiB
C

/* date = April 11th 2022 3:22 pm */
#ifndef LUMENARIUM_GEOMETRY_H
#define LUMENARIUM_GEOMETRY_H
// Utility functions for working with 3d geometry
// NOTE(PS): the Buffer vs Buffer_Builder distinction
// lets a static sized buffer exist, and be auto 'exported' or 'available'
// from a larger data structure that also stores enough data to incrementally
// build the buffer
// NOTE(PS): @IMPORTANT!!!
// at the moment this builder doesn't support allowing for the elements
// of a vertex to be in an order other than position tex color
// and in any other packing than tightly packed
typedef u32 Geo_Vertex_Buffer_Storage;
enum
{
GeoVertexBufferStorage_None = 0,
GeoVertexBufferStorage_Position = 1,
GeoVertexBufferStorage_TexCoord = 2,
GeoVertexBufferStorage_Color = 4
};
typedef struct Geo_Vertex_Buffer Geo_Vertex_Buffer;
struct Geo_Vertex_Buffer
{
r32* values;
u32 len;
Geo_Vertex_Buffer_Storage storage;
u32 stride;
};
typedef struct Geo_Vertex_Buffer_Builder Geo_Vertex_Buffer_Builder;
struct Geo_Vertex_Buffer_Builder
{
union
{
Geo_Vertex_Buffer buffer;
struct
{
// NOTE(PS): @Maintainence
// this must always match the layout of Geo_Vertex_Buffer
r32* values;
u32 len;
Geo_Vertex_Buffer_Storage storage;
u32 stride;
};
};
u32 cap;
};
typedef struct Geo_Index_Buffer Geo_Index_Buffer;
struct Geo_Index_Buffer
{
u32* values;
u32 len;
};
typedef struct Geo_Index_Buffer_Builder Geo_Index_Buffer_Builder;
struct Geo_Index_Buffer_Builder
{
union
{
Geo_Index_Buffer buffer;
struct
{
// NOTE(PS): @Maintainence
// this must always match the layout of Geo_Index_Buffer
u32* values;
u32 len;
};
};
u32 cap;
};
typedef struct Geo_Quad_Buffer Geo_Quad_Buffer;
struct Geo_Quad_Buffer
{
Geo_Vertex_Buffer buffer_vertex;
Geo_Index_Buffer buffer_index;
};
typedef struct Geo_Quad_Buffer_Builder Geo_Quad_Buffer_Builder;
struct Geo_Quad_Buffer_Builder
{
Geo_Vertex_Buffer_Builder buffer_vertex;
Geo_Index_Buffer_Builder buffer_index;
};
internal Geo_Vertex_Buffer_Builder geo_vertex_buffer_builder_create(Allocator* a, u32 cap, Geo_Vertex_Buffer_Storage storage);
internal Geo_Index_Buffer_Builder geo_index_buffer_builder_create(Allocator* a, u32 cap);
internal Geo_Quad_Buffer_Builder ggeo_quad_buffer_builder_create(Allocator* a, u32 vertex_cap, Geo_Vertex_Buffer_Storage storage, u32 index_cap);
// Vertex Buffer
internal u32 geo_vertex_buffer_builder_push_vtc(Geo_Vertex_Buffer_Builder* b, v3 v, v2 t, v4 c);
internal u32 geo_vertex_buffer_builder_push_vt(Geo_Vertex_Buffer_Builder* b, v3 v, v2 t);
internal u32 geo_vertex_buffer_builder_push_v(Geo_Vertex_Buffer_Builder* b, v3 v);
// Index Buffer
internal u32 geo_index_buffer_builder_push(Geo_Index_Buffer_Builder* b, u32 i);
internal void geo_index_buffer_builder_push_tri(Geo_Index_Buffer_Builder* b, u32 i0, u32 i1, u32 i2);
internal void geo_index_buffer_builder_push_quad(Geo_Index_Buffer_Builder* b, u32 i0, u32 i1, u32 i2, u32 i3);
// Quad Buffer
internal void geo_quad_buffer_builder_push_vtc(Geo_Quad_Buffer_Builder* b, v3 p0, v3 p1, v3 p2, v3 p3, v2 t0, v2 t1, v2 t2, v2 t3, v4 c);
internal void geo_quad_buffer_builder_push_vt(Geo_Quad_Buffer_Builder* b, v3 p0, v3 p1, v3 p2, v3 p3, v2 t0, v2 t1, v2 t2, v2 t3);
internal void geo_quad_buffer_builder_push_v(Geo_Quad_Buffer_Builder* b, v3 p0, v3 p1, v3 p2, v3 p3);
internal Geo_Quad_Buffer geo_quad_buffer_builder_get_static_buffer(Geo_Quad_Buffer_Builder* b);
/////////////////////////////////////////////
// Implementation
internal u32
geo_vertex_buffer_builder_stride(Geo_Vertex_Buffer_Storage storage)
{
u32 result = 0;
result += has_flag(storage, GeoVertexBufferStorage_Position) ? 3 : 0;
result += has_flag(storage, GeoVertexBufferStorage_TexCoord) ? 2 : 0;
result += has_flag(storage, GeoVertexBufferStorage_Color) ? 4 : 0;
return result;
}
#ifdef DEBUG
# define geo_vertex_buffers_validate(g) geo_vertex_buffers_validate_(g)
#else
# define geo_vertex_buffers_validate(g)
#endif
void
geo_vertex_buffers_validate_(Geo_Vertex_Buffer_Builder* b)
{
// before start
u32* sentinel = (u32*)(b->values - 2);
assert(sentinel[0] == 0xF0F0F0F0);
assert(sentinel[1] == 0x0F0F0F0F);
// after end
sentinel = (u32*)(b->values + (b->cap * b->stride));
assert(sentinel[0] == 0xFFFF000F);
assert(sentinel[1] == 0xF000FFFF);
}
internal Geo_Vertex_Buffer_Builder
geo_vertex_buffer_builder_create(Allocator* a, u32 cap, Geo_Vertex_Buffer_Storage storage)
{
u32 stride = geo_vertex_buffer_builder_stride(storage);
u32 size = cap * stride;
u32 alloc_size = size;
#ifdef DEBUG
alloc_size += 4;
#endif
Geo_Vertex_Buffer_Builder result = {};
zero_struct(result);
result.cap = cap;
result.storage = storage;
result.stride = stride;
result.values = allocator_alloc_array(a, r32, alloc_size);
#ifdef DEBUG
u32* sentinel = (u32*)result.values;
sentinel[0] = 0xF0F0F0F0;
sentinel[1] = 0x0F0F0F0F;
sentinel = (u32*)(result.values + alloc_size - 2);
result.values += 2;
sentinel[0] = 0xFFFF000F;
sentinel[1] = 0xF000FFFF;
#endif
geo_vertex_buffers_validate(&result);
return result;
}
internal Geo_Index_Buffer_Builder
geo_index_buffer_builder_create(Allocator* a, u32 cap)
{
Geo_Index_Buffer_Builder result = {};
zero_struct(result);
result.cap = cap;
result.values = allocator_alloc_array(a, u32, cap);
return result;
}
internal Geo_Quad_Buffer_Builder
geo_quad_buffer_builder_create(Allocator* a, u32 vertex_cap, Geo_Vertex_Buffer_Storage storage, u32 index_cap)
{
Geo_Quad_Buffer_Builder result = {};
result.buffer_vertex = geo_vertex_buffer_builder_create(a, vertex_cap, storage);
result.buffer_index = geo_index_buffer_builder_create(a, index_cap);
return result;
}
// Vertex Buffer
internal u32
geo_vertex_buffer_builder_push_vtc(Geo_Vertex_Buffer_Builder* b, v3 v, v2 t, v4 c)
{
geo_vertex_buffers_validate(b);
assert(b->len < b->cap);
u32 result = b->len++;
u32 offset = result * b->stride;
assert((offset + b->stride) <= (b->cap * b->stride));
r32* at = b->values + offset;
if (has_flag(b->storage, GeoVertexBufferStorage_Position))
{
*at++ = v.x;
*at++ = v.y;
*at++ = v.z;
}
if (has_flag(b->storage, GeoVertexBufferStorage_TexCoord))
{
*at++ = t.x;
*at++ = t.y;
}
if (has_flag(b->storage, GeoVertexBufferStorage_Color))
{
*at++ = c.x;
*at++ = c.y;
*at++ = c.z;
*at++ = c.w;
}
geo_vertex_buffers_validate(b);
return result;
}
internal u32
geo_vertex_buffer_builder_push_vt(Geo_Vertex_Buffer_Builder* b, v3 v, v2 t)
{
return geo_vertex_buffer_builder_push_vtc(b, v, t, (v4){0});
}
internal u32
geo_vertex_buffer_builder_push_v(Geo_Vertex_Buffer_Builder* b, v3 v)
{
return geo_vertex_buffer_builder_push_vtc(b, v, (v2){0}, (v4){0});
}
// Index Buffer
internal u32
geo_index_buffer_builder_push(Geo_Index_Buffer_Builder* b, u32 i)
{
assert(b->len < b->cap);
u32 result = b->len++;
b->values[result] = i;
return result;
}
internal void
geo_index_buffer_builder_push_tri(Geo_Index_Buffer_Builder* b, u32 i0, u32 i1, u32 i2)
{
geo_index_buffer_builder_push(b, i0);
geo_index_buffer_builder_push(b, i1);
geo_index_buffer_builder_push(b, i2);
}
internal void
geo_index_buffer_builder_push_quad(Geo_Index_Buffer_Builder* b, u32 i0, u32 i1, u32 i2, u32 i3)
{
geo_index_buffer_builder_push_tri(b, i0, i1, i2);
geo_index_buffer_builder_push_tri(b, i0, i2, i3);
}
// Quad Buffer
internal void
geo_quad_buffer_builder_push_vtc(Geo_Quad_Buffer_Builder* b, v3 p0, v3 p1, v3 p2, v3 p3, v2 t0, v2 t1, v2 t2, v2 t3, v4 c)
{
u32 i0 = geo_vertex_buffer_builder_push_vtc(&b->buffer_vertex, p0, t0, c);
u32 i1 = geo_vertex_buffer_builder_push_vtc(&b->buffer_vertex, p1, t1, c);
u32 i2 = geo_vertex_buffer_builder_push_vtc(&b->buffer_vertex, p2, t2, c);
u32 i3 = geo_vertex_buffer_builder_push_vtc(&b->buffer_vertex, p3, t3, c);
geo_index_buffer_builder_push_quad(&b->buffer_index, i0, i1, i2, i3);
}
internal void
geo_quad_buffer_builder_push_vt(Geo_Quad_Buffer_Builder* b, v3 p0, v3 p1, v3 p2, v3 p3, v2 t0, v2 t1, v2 t2, v2 t3)
{
u32 i0 = geo_vertex_buffer_builder_push_vtc(&b->buffer_vertex, p0, t0, (v4){});
u32 i1 = geo_vertex_buffer_builder_push_vtc(&b->buffer_vertex, p1, t1, (v4){});
u32 i2 = geo_vertex_buffer_builder_push_vtc(&b->buffer_vertex, p2, t2, (v4){});
u32 i3 = geo_vertex_buffer_builder_push_vtc(&b->buffer_vertex, p3, t3, (v4){});
geo_index_buffer_builder_push_quad(&b->buffer_index, i0, i1, i2, i3);
}
internal void
geo_quad_buffer_builder_push_v(Geo_Quad_Buffer_Builder* b, v3 p0, v3 p1, v3 p2, v3 p3)
{
u32 i0 = geo_vertex_buffer_builder_push_vtc(&b->buffer_vertex, p0, (v2){}, (v4){});
u32 i1 = geo_vertex_buffer_builder_push_vtc(&b->buffer_vertex, p1, (v2){}, (v4){});
u32 i2 = geo_vertex_buffer_builder_push_vtc(&b->buffer_vertex, p2, (v2){}, (v4){});
u32 i3 = geo_vertex_buffer_builder_push_vtc(&b->buffer_vertex, p3, (v2){}, (v4){});
geo_index_buffer_builder_push_quad(&b->buffer_index, i0, i1, i2, i3);
}
internal Geo_Quad_Buffer
geo_quad_buffer_builder_get_static_buffer(Geo_Quad_Buffer_Builder* b)
{
Geo_Quad_Buffer result = {};
result.buffer_vertex = b->buffer_vertex.buffer;
result.buffer_index = b->buffer_index.buffer;
return result;
}
#endif //LUMENARIUM_GEOMETRY_H