#version 110 #define M_PI 3.1415926535897932384626433832795 // 2D texture (1D texture split by the rows) of color along the object Z axis. uniform sampler2D z_texture; // Scaling from the Z texture rows coordinate to the normalized texture row coordinate. uniform float z_to_texture_row; uniform float z_texture_row_to_normalized; uniform float z_cursor; uniform float z_cursor_band_width; // x = tainted, y = specular; varying vec2 intensity; varying float object_z; void main() { float object_z_row = z_to_texture_row * object_z; // Index of the row in the texture. float z_texture_row = floor(object_z_row); // Normalized coordinate from 0. to 1. float z_texture_col = object_z_row - z_texture_row; float z_blend = 0.25 * cos(min(M_PI, abs(M_PI * (object_z - z_cursor) * 1.8 / z_cursor_band_width))) + 0.25; // Calculate level of detail from the object Z coordinate. // This makes the slowly sloping surfaces to be show with high detail (with stripes), // and the vertical surfaces to be shown with low detail (no stripes) float z_in_cells = object_z_row * 190.; // Gradient of Z projected on the screen. float dx_vtc = dFdx(z_in_cells); float dy_vtc = dFdy(z_in_cells); float lod = clamp(0.5 * log2(max(dx_vtc * dx_vtc, dy_vtc * dy_vtc)), 0., 1.); // Sample the Z texture. Texture coordinates are normalized to <0, 1>. vec4 color = mix(texture2D(z_texture, vec2(z_texture_col, z_texture_row_to_normalized * (z_texture_row + 0.5 )), -10000.), texture2D(z_texture, vec2(z_texture_col, z_texture_row_to_normalized * (z_texture_row * 2. + 1.)), 10000.), lod); // Mix the final color. gl_FragColor = vec4(intensity.y, intensity.y, intensity.y, 1.0) + intensity.x * mix(color, vec4(1.0, 1.0, 0.0, 1.0), z_blend); }