[2829] | 1 | //////////////////// |
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| 2 | // Screen Spaced Ambient Occlusion shader |
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[2834] | 3 | // mainly based on shader of Alexander Kusternig |
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[2829] | 4 | |
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[2834] | 5 | //#define NUM_SAMPLES 8 |
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| 6 | #define NUM_SAMPLES 16 |
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[2837] | 7 | |
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[2834] | 8 | // rule of thumb: approx 1 / NUM_SAMPLES |
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[2837] | 9 | #define SAMPLE_INTENSITY 0.2 |
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| 10 | //#define SAMPLE_INTENSITY 0.125f |
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[2834] | 11 | |
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[2853] | 12 | #define AREA_SIZE 9e-1f |
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[2837] | 13 | #define VIEW_CORRECTION_SCALE 0.3f |
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| 14 | #define DISTANCE_SCALE 1e-6f |
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[2821] | 15 | |
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[2810] | 16 | struct fragment |
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| 17 | { |
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[2836] | 18 | // normalized screen position |
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| 19 | float4 pos: WPOS; |
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| 20 | float4 texCoord: TEXCOORD0; |
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| 21 | float3 view: COLOR0; |
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[2810] | 22 | }; |
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| 23 | |
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| 24 | |
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| 25 | struct pixel |
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| 26 | { |
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[2837] | 27 | float4 color: COLOR0; |
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[2810] | 28 | }; |
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| 29 | |
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| 30 | |
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[2814] | 31 | float2 reflect(float2 pt, float2 n) |
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| 32 | { |
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| 33 | // distance to plane |
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| 34 | float d = dot(n, pt); |
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| 35 | // reflect around plane |
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| 36 | float2 rpt = pt - d * 2.0f * n; |
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[2834] | 37 | |
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[2814] | 38 | //return pt; |
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| 39 | return rpt; |
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| 40 | } |
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| 41 | |
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| 42 | |
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[2821] | 43 | float2 rotate(float2 pt, float2 n) |
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| 44 | { |
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[2834] | 45 | float2 ptTransformed; |
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| 46 | ptTransformed.x = n.r * pt.x - n.g * pt.y; |
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| 47 | ptTransformed.y = n.g * pt.x + n.r * pt.y; |
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[2821] | 48 | |
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[2834] | 49 | return ptTransformed; |
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[2821] | 50 | } |
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| 51 | |
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| 52 | |
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[2810] | 53 | float ssao(fragment IN, |
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[2834] | 54 | uniform sampler2D positions, |
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| 55 | uniform sampler2D noiseTexture, |
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| 56 | uniform float2 samples[NUM_SAMPLES], |
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| 57 | uniform float3 currentNormal, |
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| 58 | uniform float3 currentViewDir, |
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| 59 | uniform float noiseMultiplier, |
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| 60 | uniform float4 centerPosition |
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| 61 | ) |
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[2810] | 62 | { |
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[2834] | 63 | // the w coordinate from the persp. projection |
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| 64 | float w = centerPosition.w; |
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[2810] | 65 | |
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[2834] | 66 | // Check in a circular area around the current position. |
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| 67 | // Shoot vectors to the positions there, and check the angle to these positions. |
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| 68 | // Summing up these angles gives an estimation of the occlusion at the current position. |
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[2810] | 69 | |
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[2834] | 70 | float total_ao = 0.0; |
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[2825] | 71 | |
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[2834] | 72 | const float areaSize = 5e-1f; |
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[2833] | 73 | |
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[2834] | 74 | for (int i = 0; i < NUM_SAMPLES; i ++) |
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| 75 | { |
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| 76 | float2 offset = samples[i]; |
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[2833] | 77 | |
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[2834] | 78 | //sample noisetex; r stores costheta, g stores sintheta |
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[2835] | 79 | float2 mynoise = tex2D(noiseTexture, IN.texCoord.xy * noiseMultiplier).xy * 2.0f - 1.0f; |
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[2833] | 80 | |
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[2834] | 81 | // rotation |
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| 82 | //float2 offsetTransformed = offset; |
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[2835] | 83 | float2 offsetTransformed = rotate(offset, mynoise); |
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[2834] | 84 | //float2 offsetTransformed = reflect(offset, noise); |
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| 85 | |
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| 86 | // weight with projected coordinate to reach similar kernel size for near and far |
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| 87 | float2 texcoord = IN.texCoord.xy + offsetTransformed * AREA_SIZE * w; |
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| 88 | |
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| 89 | float3 sample_position = tex2D(positions, texcoord).xyz; |
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| 90 | |
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| 91 | float3 vector_to_sample = sample_position - centerPosition.xyz; |
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| 92 | float length_to_sample = length(vector_to_sample); |
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| 93 | float3 direction_to_sample = vector_to_sample / length_to_sample; |
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| 94 | |
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| 95 | // Angle between current normal and direction to sample controls AO intensity. |
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| 96 | float cos_angle = dot(direction_to_sample, currentNormal); |
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| 97 | cos_angle = max(cos_angle, 0.0f); |
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| 98 | |
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| 99 | // distance between current position and sample position controls AO intensity. |
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| 100 | float distance_intensity = |
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[2837] | 101 | (SAMPLE_INTENSITY * DISTANCE_SCALE) / (DISTANCE_SCALE + length_to_sample * length_to_sample); |
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[2834] | 102 | |
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| 103 | // if normal perpenticular to view dir, only half of the samples count |
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[2837] | 104 | float view_correction = 1.0f + VIEW_CORRECTION_SCALE * (1.0f - dot(currentViewDir, currentNormal)); |
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[2834] | 105 | |
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| 106 | total_ao += cos_angle * distance_intensity * view_correction; |
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| 107 | } |
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| 108 | |
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| 109 | return (1.0f - total_ao); |
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[2810] | 110 | } |
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| 111 | |
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| 112 | |
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[2834] | 113 | float4 globIllum(fragment IN, |
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| 114 | uniform sampler2D colors, |
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| 115 | uniform sampler2D positions, |
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| 116 | uniform sampler2D noiseTexture, |
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| 117 | uniform float2 samples[NUM_SAMPLES], |
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| 118 | uniform float3 currentNormal, |
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| 119 | uniform float3 currentViewDir, |
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| 120 | uniform float noiseMultiplier, |
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[2837] | 121 | uniform float4 centerPosition |
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| 122 | ) |
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[2834] | 123 | { |
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| 124 | // the w coordinate from the persp. projection |
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| 125 | float w = centerPosition.w; |
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| 126 | |
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| 127 | // Check in a circular area around the current position. |
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| 128 | // Shoot vectors to the positions there, and check the angle to these positions. |
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| 129 | // Summing up these angles gives an estimation of the occlusion at the current position. |
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| 130 | |
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| 131 | float total_ao = 0.0; |
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| 132 | float3 total_color = float3(0.0f); |
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| 133 | |
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| 134 | const float areaSize = 5e-1f; |
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| 135 | |
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| 136 | for (int i = 0; i < NUM_SAMPLES; i ++) |
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| 137 | { |
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| 138 | float2 offset = samples[i]; |
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| 139 | |
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| 140 | //sample noisetex; r stores costheta, g stores sintheta |
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[2835] | 141 | float2 mynoise = tex2D(noiseTexture, IN.texCoord.xy * noiseMultiplier).xy * 2.0f - 1.0f; |
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[2834] | 142 | |
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| 143 | // rotation |
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[2835] | 144 | float2 offsetTransformed = rotate(offset, mynoise); |
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[2834] | 145 | |
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| 146 | // weight with projected coordinate to reach similar kernel size for near and far |
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| 147 | float2 texcoord = IN.texCoord.xy + offsetTransformed * AREA_SIZE * w; |
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| 148 | |
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| 149 | float3 sample_position = tex2D(positions, texcoord).xyz; |
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| 150 | float3 sample_color = tex2D(colors, texcoord).xyz; |
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| 151 | |
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| 152 | float3 vector_to_sample = sample_position - centerPosition.xyz; |
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| 153 | float length_to_sample = length(vector_to_sample); |
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| 154 | float3 direction_to_sample = vector_to_sample / length_to_sample; |
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| 155 | |
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| 156 | // Angle between current normal and direction to sample controls AO intensity. |
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| 157 | float cos_angle = dot(direction_to_sample, currentNormal); |
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| 158 | cos_angle = max(cos_angle, 0.0f); |
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| 159 | |
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| 160 | // distance between current position and sample position controls AO intensity. |
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| 161 | float distance_intensity = |
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[2837] | 162 | (SAMPLE_INTENSITY * DISTANCE_SCALE) / (DISTANCE_SCALE + length_to_sample * length_to_sample); |
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[2834] | 163 | |
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| 164 | // if normal perpenticular to view dir, only half of the samples count |
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[2837] | 165 | float view_correction = 1.0f + VIEW_CORRECTION_SCALE * (1.0f - dot(currentViewDir, currentNormal)); |
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[2834] | 166 | |
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| 167 | total_ao += cos_angle * distance_intensity * view_correction; |
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[2836] | 168 | total_color += cos_angle * distance_intensity * view_correction * sample_color * 0.3f; |
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[2834] | 169 | } |
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| 170 | |
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| 171 | return float4(total_color, 1.0f - total_ao); |
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| 172 | } |
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| 173 | |
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| 174 | |
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[2820] | 175 | float4 shade(fragment IN, |
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[2834] | 176 | uniform sampler2D colors, |
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| 177 | uniform sampler2D positions, |
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| 178 | uniform float3 normal, |
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| 179 | uniform float amb) |
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[2810] | 180 | { |
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[2834] | 181 | float4 lightDir = float4(0.8f, -1.0f, 0.7f, 0.0f); |
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| 182 | float4 lightDir2 = float4(-0.5f, 0.5f, 0.4f, 0.0f); |
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[2810] | 183 | |
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[2834] | 184 | float4 color = tex2D(colors, IN.texCoord.xy); |
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[2810] | 185 | |
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[2834] | 186 | float4 position = tex2D(positions, IN.texCoord.xy); |
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[2810] | 187 | |
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[2834] | 188 | float4 ambient = 0.3f; |
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[2815] | 189 | |
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[2834] | 190 | // float3 L = normalize(lightPosition - position); |
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| 191 | float3 light = normalize(lightDir.xyz); |
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| 192 | float3 light2 = normalize(lightDir2.xyz); |
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| 193 | |
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| 194 | float diffuseLight = max(dot(normal, light), 0.0f); |
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| 195 | float diffuseLight2 = max(dot(normal, light2), 0.0f); |
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| 196 | |
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| 197 | float diffuse = diffuseLight + diffuseLight2; |
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| 198 | //float diffuse = diffuseLight; |
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| 199 | |
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| 200 | return (ambient + diffuse) * color * (1.0f - amb) + amb * color; |
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[2820] | 201 | } |
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| 202 | |
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| 203 | |
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[2821] | 204 | pixel main_ssao(fragment IN, |
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[2834] | 205 | uniform sampler2D colors, |
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| 206 | uniform sampler2D positions, |
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| 207 | uniform sampler2D normals, |
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| 208 | uniform sampler2D noiseTexture, |
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| 209 | uniform float2 samples[NUM_SAMPLES], |
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| 210 | uniform float noiseMultiplier, |
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| 211 | uniform sampler2D oldTex, |
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[2835] | 212 | const uniform float4x4 oldModelViewProj, |
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[2837] | 213 | uniform float maxDepth, |
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| 214 | uniform float expFactor |
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[2834] | 215 | ) |
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[2821] | 216 | { |
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[2834] | 217 | pixel OUT; |
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[2821] | 218 | |
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[2834] | 219 | float4 normal = tex2D(normals, IN.texCoord.xy); |
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| 220 | float amb = normal.w; |
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[2822] | 221 | |
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[2834] | 222 | // expand normal |
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| 223 | normal = normalize(normal * 2.0f - 1.0f); |
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| 224 | float3 viewDir = normalize(IN.view * 2.0f - float3(1.0f)); |
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[2822] | 225 | |
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[2834] | 226 | // the current world position |
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| 227 | float4 centerPosition = tex2D(positions, IN.texCoord.xy); |
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| 228 | |
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| 229 | float4 col = shade(IN, colors, positions, normal.xyz, amb); |
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[2821] | 230 | |
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[2837] | 231 | float ao = ssao(IN, positions, noiseTexture, samples, normal.xyz, viewDir, noiseMultiplier, centerPosition); |
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| 232 | float4 attenuated_color = ao * col; |
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[2834] | 233 | |
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[2837] | 234 | //float4 new_col = globIllum(IN, colors, positions, noiseTexture, samples, normal.xyz, viewDir, noiseMultiplier, centerPosition); |
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| 235 | //float ao = new_col.w; |
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| 236 | //float4 attenuated_color = ao * col + new_col; |
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| 237 | |
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| 238 | const float x = expFactor; |
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[2834] | 239 | |
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[2835] | 240 | float4 dummy = centerPosition * maxDepth; |
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[2834] | 241 | dummy.w = 1.0f; |
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[2836] | 242 | |
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[2834] | 243 | float4 oldPos = mul(oldModelViewProj, dummy); |
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| 244 | |
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| 245 | float newDepth = oldPos.z / oldPos.w; |
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| 246 | |
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| 247 | float2 tex = (oldPos.xy / oldPos.w) * 0.5f + 0.5f; |
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| 248 | float4 col1 = tex2D(oldTex, tex); |
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| 249 | |
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| 250 | float oldDepth = col1.w; |
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[2837] | 251 | float depthDif = 1.0f - newDepth / oldDepth; |
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[2834] | 252 | |
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[2837] | 253 | if ((tex.x >= 0.0f) && (tex.x < 1.0f) && |
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| 254 | (tex.y >= 0.0f) && (tex.y < 1.0f) && |
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[2838] | 255 | (abs(depthDif) < 8e-5f)) |
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[2853] | 256 | { |
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[2837] | 257 | OUT.color = attenuated_color * expFactor + col1 * float4(1.0f - expFactor); |
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[2853] | 258 | } |
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[2835] | 259 | else |
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[2853] | 260 | { |
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[2835] | 261 | OUT.color = attenuated_color; |
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[2853] | 262 | } |
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[2834] | 263 | |
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| 264 | OUT.color.w = tex2D(colors, IN.texCoord.xy).w; |
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| 265 | |
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| 266 | return OUT; |
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[2821] | 267 | } |
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| 268 | |
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| 269 | |
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[2820] | 270 | pixel main(fragment IN, |
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[2834] | 271 | uniform sampler2D colors, |
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| 272 | uniform sampler2D positions, |
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[2837] | 273 | uniform sampler2D normals |
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[2834] | 274 | ) |
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[2820] | 275 | { |
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[2834] | 276 | pixel OUT; |
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[2820] | 277 | |
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[2834] | 278 | float4 normal = tex2D(normals, IN.texCoord.xy); |
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| 279 | float amb = normal.w; |
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[2821] | 280 | |
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[2834] | 281 | // expand normal |
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| 282 | normal = normalize(normal * 2.0f - float4(1.0f)); |
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| 283 | |
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| 284 | float4 col = shade(IN, colors, positions, normal.xyz, amb); |
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[2837] | 285 | OUT.color = col; |
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[2834] | 286 | |
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| 287 | return OUT; |
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[2810] | 288 | } |
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