diff options
Diffstat (limited to 'src/mbgl/shaders/raster.cpp')
-rw-r--r-- | src/mbgl/shaders/raster.cpp | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/src/mbgl/shaders/raster.cpp b/src/mbgl/shaders/raster.cpp index f454078310..98291bfec6 100644 --- a/src/mbgl/shaders/raster.cpp +++ b/src/mbgl/shaders/raster.cpp @@ -20,7 +20,12 @@ varying vec2 v_pos1; void main() { gl_Position = u_matrix * vec4(a_pos, 0, 1); - v_pos0 = (((a_texture_pos / 32767.0) - 0.5) / u_buffer_scale ) + 0.5; + // We are using Int16 for texture position coordinates to give us enough precision for + // fractional coordinates. We use 8192 to scale the texture coordinates in the buffer + // as an arbitrarily high number to preserve adequate precision when rendering. + // This is also the same value as the EXTENT we are using for our tile buffer pos coordinates, + // so math for modifying either is consistent. + v_pos0 = (((a_texture_pos / 8192.0) - 0.5) / u_buffer_scale ) + 0.5; v_pos1 = (v_pos0 * u_scale_parent) + u_tl_parent; } |