refactor atlas implementation

src/lua/pxl8.lua

@@ -69,6 +69,22 @@ function pxl8.load_sprite(filepath)
     end
 end
 
+function pxl8.create_texture(pixels, width, height)
+    local pixel_data = ffi.new("u8[?]", width * height)
+    for i = 0, width * height - 1 do
+        pixel_data[i] = pixels[i + 1] or 0
+    end
+    local result = C.pxl8_gfx_create_texture(gfx, pixel_data, width, height)
+    if result < 0 then
+        return nil
+    end
+    return result
+end
+
+function pxl8.upload_atlas()
+    C.pxl8_gfx_upload_atlas(gfx)
+end
+
 -- log
 function pxl8.info(msg)
     C.pxl8_lua_info(msg)
@@ -267,6 +283,10 @@ function pxl8.set_wireframe(wireframe)
     C.pxl8_3d_set_wireframe(gfx, wireframe)
 end
 
+function pxl8.set_affine_textures(affine)
+    C.pxl8_3d_set_affine_textures(gfx, affine)
+end
+
 function pxl8.set_backface_culling(culling)
     C.pxl8_3d_set_backface_culling(gfx, culling)
 end
@@ -278,6 +298,14 @@ function pxl8.draw_triangle_3d(v0, v1, v2, color)
     C.pxl8_3d_draw_triangle_raw(gfx, vec0, vec1, vec2, color)
 end
 
+function pxl8.draw_triangle_3d_textured(v0, v1, v2, uv0, uv1, uv2, texture_id)
+    local vec0 = ffi.new("pxl8_vec3", {x = v0[1], y = v0[2], z = v0[3]})
+    local vec1 = ffi.new("pxl8_vec3", {x = v1[1], y = v1[2], z = v1[3]})
+    local vec2 = ffi.new("pxl8_vec3", {x = v2[1], y = v2[2], z = v2[3]})
+    C.pxl8_3d_draw_triangle_textured(gfx, vec0, vec1, vec2,
+        uv0[1], uv0[2], uv1[1], uv1[2], uv2[1], uv2[2], texture_id)
+end
+
 function pxl8.draw_line_3d(p0, p1, color)
     local vec0 = ffi.new("pxl8_vec3", {x = p0[1], y = p0[2], z = p0[3]})
     local vec1 = ffi.new("pxl8_vec3", {x = p1[1], y = p1[2], z = p1[3]})