6 out vec2 patch_bottom_left_texel; // Center of bottom-left texel of patch.
8 uniform float inv_flow_width, inv_flow_height;
9 uniform float inv_image_width, inv_image_height;
13 // The result of glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0) is:
15 // 2.000 0.000 0.000 -1.000
16 // 0.000 2.000 0.000 -1.000
17 // 0.000 0.000 -2.000 -1.000
18 // 0.000 0.000 0.000 1.000
19 gl_Position = vec4(2.0 * position.x - 1.0, 2.0 * position.y - 1.0, -1.0, 1.0);
22 vec2 patch_bottom_left = texcoord - vec2(0.5, 0.5) * vec2(inv_flow_width, inv_flow_height);
23 patch_bottom_left_texel = patch_bottom_left + vec2(0.5, 0.5) * vec2(inv_image_width, inv_image_height);