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- /* clang-format off */
- [vertex]
- layout(location = 0) in highp vec4 vertex_attrib;
- /* clang-format on */
- void main() {
- gl_Position = vertex_attrib;
- gl_Position.z = 1.0;
- }
- /* clang-format off */
- [fragment]
- uniform sampler2D source_ssao; //texunit:0
- /* clang-format on */
- uniform sampler2D source_depth; //texunit:1
- uniform sampler2D source_normal; //texunit:3
- layout(location = 0) out float visibility;
- //////////////////////////////////////////////////////////////////////////////////////////////
- // Tunable Parameters:
- /** Increase to make depth edges crisper. Decrease to reduce flicker. */
- uniform float edge_sharpness;
- /** Step in 2-pixel intervals since we already blurred against neighbors in the
- first AO pass. This constant can be increased while R decreases to improve
- performance at the expense of some dithering artifacts.
- Morgan found that a scale of 3 left a 1-pixel checkerboard grid that was
- unobjectionable after shading was applied but eliminated most temporal incoherence
- from using small numbers of sample taps.
- */
- uniform int filter_scale;
- /** Filter radius in pixels. This will be multiplied by SCALE. */
- #define R (4)
- //////////////////////////////////////////////////////////////////////////////////////////////
- // Gaussian coefficients
- const float gaussian[R + 1] =
- //float[](0.356642, 0.239400, 0.072410, 0.009869);
- //float[](0.398943, 0.241971, 0.053991, 0.004432, 0.000134); // stddev = 1.0
- float[](0.153170, 0.144893, 0.122649, 0.092902, 0.062970); // stddev = 2.0
- //float[](0.111220, 0.107798, 0.098151, 0.083953, 0.067458, 0.050920, 0.036108); // stddev = 3.0
- /** (1, 0) or (0, 1)*/
- uniform ivec2 axis;
- uniform float camera_z_far;
- uniform float camera_z_near;
- uniform ivec2 screen_size;
- void main() {
- ivec2 ssC = ivec2(gl_FragCoord.xy);
- float depth = texelFetch(source_depth, ssC, 0).r;
- //vec3 normal = texelFetch(source_normal,ssC,0).rgb * 2.0 - 1.0;
- depth = depth * 2.0 - 1.0;
- depth = 2.0 * camera_z_near * camera_z_far / (camera_z_far + camera_z_near - depth * (camera_z_far - camera_z_near));
- float depth_divide = 1.0 / camera_z_far;
- //depth *= depth_divide;
- /*
- if (depth > camera_z_far * 0.999) {
- discard; //skybox
- }
- */
- float sum = texelFetch(source_ssao, ssC, 0).r;
- // Base weight for depth falloff. Increase this for more blurriness,
- // decrease it for better edge discrimination
- float BASE = gaussian[0];
- float totalWeight = BASE;
- sum *= totalWeight;
- ivec2 clamp_limit = screen_size - ivec2(1);
- for (int r = -R; r <= R; ++r) {
- // We already handled the zero case above. This loop should be unrolled and the static branch optimized out,
- // so the IF statement has no runtime cost
- if (r != 0) {
- ivec2 ppos = ssC + axis * (r * filter_scale);
- float value = texelFetch(source_ssao, clamp(ppos, ivec2(0), clamp_limit), 0).r;
- ivec2 rpos = clamp(ppos, ivec2(0), clamp_limit);
- float temp_depth = texelFetch(source_depth, rpos, 0).r;
- //vec3 temp_normal = texelFetch(source_normal, rpos, 0).rgb * 2.0 - 1.0;
- temp_depth = temp_depth * 2.0 - 1.0;
- temp_depth = 2.0 * camera_z_near * camera_z_far / (camera_z_far + camera_z_near - temp_depth * (camera_z_far - camera_z_near));
- // temp_depth *= depth_divide;
- // spatial domain: offset gaussian tap
- float weight = 0.3 + gaussian[abs(r)];
- //weight *= max(0.0,dot(temp_normal,normal));
- // range domain (the "bilateral" weight). As depth difference increases, decrease weight.
- weight *= max(0.0, 1.0 - edge_sharpness * abs(temp_depth - depth));
- sum += value * weight;
- totalWeight += weight;
- }
- }
- const float epsilon = 0.0001;
- visibility = sum / (totalWeight + epsilon);
- }
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