diff options
Diffstat (limited to 'drivers/gles2/shaders/ssao.glsl')
| -rw-r--r-- | drivers/gles2/shaders/ssao.glsl | 283 |
1 files changed, 0 insertions, 283 deletions
diff --git a/drivers/gles2/shaders/ssao.glsl b/drivers/gles2/shaders/ssao.glsl deleted file mode 100644 index 0fd29e8dcc..0000000000 --- a/drivers/gles2/shaders/ssao.glsl +++ /dev/null @@ -1,283 +0,0 @@ -/* 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] - -#define TWO_PI 6.283185307179586476925286766559 - -#ifdef SSAO_QUALITY_HIGH - -#define NUM_SAMPLES (80) - -#endif - -#ifdef SSAO_QUALITY_LOW - -#define NUM_SAMPLES (15) - -#endif - -#if !defined(SSAO_QUALITY_LOW) && !defined(SSAO_QUALITY_HIGH) - -#define NUM_SAMPLES (40) - -#endif - -// If using depth mip levels, the log of the maximum pixel offset before we need to switch to a lower -// miplevel to maintain reasonable spatial locality in the cache -// If this number is too small (< 3), too many taps will land in the same pixel, and we'll get bad variance that manifests as flashing. -// If it is too high (> 5), we'll get bad performance because we're not using the MIP levels effectively -#define LOG_MAX_OFFSET (3) - -// This must be less than or equal to the MAX_MIP_LEVEL defined in SSAO.cpp -#define MAX_MIP_LEVEL (4) - -// This is the number of turns around the circle that the spiral pattern makes. This should be prime to prevent -// taps from lining up. This particular choice was tuned for NUM_SAMPLES == 9 - -const int ROTATIONS[] = int[]( - 1, 1, 2, 3, 2, 5, 2, 3, 2, - 3, 3, 5, 5, 3, 4, 7, 5, 5, 7, - 9, 8, 5, 5, 7, 7, 7, 8, 5, 8, - 11, 12, 7, 10, 13, 8, 11, 8, 7, 14, - 11, 11, 13, 12, 13, 19, 17, 13, 11, 18, - 19, 11, 11, 14, 17, 21, 15, 16, 17, 18, - 13, 17, 11, 17, 19, 18, 25, 18, 19, 19, - 29, 21, 19, 27, 31, 29, 21, 18, 17, 29, - 31, 31, 23, 18, 25, 26, 25, 23, 19, 34, - 19, 27, 21, 25, 39, 29, 17, 21, 27); -/* clang-format on */ - -//#define NUM_SPIRAL_TURNS (7) -const int NUM_SPIRAL_TURNS = ROTATIONS[NUM_SAMPLES - 1]; - -uniform sampler2D source_depth; //texunit:0 -uniform highp usampler2D source_depth_mipmaps; //texunit:1 -uniform sampler2D source_normal; //texunit:2 - -uniform ivec2 screen_size; -uniform float camera_z_far; -uniform float camera_z_near; - -uniform float intensity_div_r6; -uniform float radius; - -#ifdef ENABLE_RADIUS2 -uniform float intensity_div_r62; -uniform float radius2; -#endif - -uniform float bias; -uniform float proj_scale; - -layout(location = 0) out float visibility; - -uniform vec4 proj_info; - -vec3 reconstructCSPosition(vec2 S, float z) { -#ifdef USE_ORTHOGONAL_PROJECTION - return vec3((S.xy * proj_info.xy + proj_info.zw), z); -#else - return vec3((S.xy * proj_info.xy + proj_info.zw) * z, z); - -#endif -} - -vec3 getPosition(ivec2 ssP) { - vec3 P; - P.z = texelFetch(source_depth, ssP, 0).r; - - P.z = P.z * 2.0 - 1.0; -#ifdef USE_ORTHOGONAL_PROJECTION - P.z = ((P.z + (camera_z_far + camera_z_near) / (camera_z_far - camera_z_near)) * (camera_z_far - camera_z_near)) / 2.0; -#else - P.z = 2.0 * camera_z_near * camera_z_far / (camera_z_far + camera_z_near - P.z * (camera_z_far - camera_z_near)); -#endif - P.z = -P.z; - - // Offset to pixel center - P = reconstructCSPosition(vec2(ssP) + vec2(0.5), P.z); - return P; -} - -/** Reconstructs screen-space unit normal from screen-space position */ -vec3 reconstructCSFaceNormal(vec3 C) { - return normalize(cross(dFdy(C), dFdx(C))); -} - -/** Returns a unit vector and a screen-space radius for the tap on a unit disk (the caller should scale by the actual disk radius) */ -vec2 tapLocation(int sampleNumber, float spinAngle, out float ssR) { - // Radius relative to ssR - float alpha = (float(sampleNumber) + 0.5) * (1.0 / float(NUM_SAMPLES)); - float angle = alpha * (float(NUM_SPIRAL_TURNS) * 6.28) + spinAngle; - - ssR = alpha; - return vec2(cos(angle), sin(angle)); -} - -/** Read the camera-space position of the point at screen-space pixel ssP + unitOffset * ssR. Assumes length(unitOffset) == 1 */ -vec3 getOffsetPosition(ivec2 ssC, vec2 unitOffset, float ssR) { - // Derivation: - // mipLevel = floor(log(ssR / MAX_OFFSET)); - int mipLevel = clamp(int(floor(log2(ssR))) - LOG_MAX_OFFSET, 0, MAX_MIP_LEVEL); - - ivec2 ssP = ivec2(ssR * unitOffset) + ssC; - - vec3 P; - - // We need to divide by 2^mipLevel to read the appropriately scaled coordinate from a MIP-map. - // Manually clamp to the texture size because texelFetch bypasses the texture unit - ivec2 mipP = clamp(ssP >> mipLevel, ivec2(0), (screen_size >> mipLevel) - ivec2(1)); - - if (mipLevel < 1) { - //read from depth buffer - P.z = texelFetch(source_depth, mipP, 0).r; - P.z = P.z * 2.0 - 1.0; -#ifdef USE_ORTHOGONAL_PROJECTION - P.z = ((P.z + (camera_z_far + camera_z_near) / (camera_z_far - camera_z_near)) * (camera_z_far - camera_z_near)) / 2.0; -#else - P.z = 2.0 * camera_z_near * camera_z_far / (camera_z_far + camera_z_near - P.z * (camera_z_far - camera_z_near)); - -#endif - P.z = -P.z; - - } else { - //read from mipmaps - uint d = texelFetch(source_depth_mipmaps, mipP, mipLevel - 1).r; - P.z = -(float(d) / 65535.0) * camera_z_far; - } - - // Offset to pixel center - P = reconstructCSPosition(vec2(ssP) + vec2(0.5), P.z); - - return P; -} - -/** Compute the occlusion due to sample with index \a i about the pixel at \a ssC that corresponds - to camera-space point \a C with unit normal \a n_C, using maximum screen-space sampling radius \a ssDiskRadius - - Note that units of H() in the HPG12 paper are meters, not - unitless. The whole falloff/sampling function is therefore - unitless. In this implementation, we factor out (9 / radius). - - Four versions of the falloff function are implemented below -*/ -float sampleAO(in ivec2 ssC, in vec3 C, in vec3 n_C, in float ssDiskRadius, in float p_radius, in int tapIndex, in float randomPatternRotationAngle) { - // Offset on the unit disk, spun for this pixel - float ssR; - vec2 unitOffset = tapLocation(tapIndex, randomPatternRotationAngle, ssR); - ssR *= ssDiskRadius; - - // The occluding point in camera space - vec3 Q = getOffsetPosition(ssC, unitOffset, ssR); - - vec3 v = Q - C; - - float vv = dot(v, v); - float vn = dot(v, n_C); - - const float epsilon = 0.01; - float radius2 = p_radius * p_radius; - - // A: From the HPG12 paper - // Note large epsilon to avoid overdarkening within cracks - //return float(vv < radius2) * max((vn - bias) / (epsilon + vv), 0.0) * radius2 * 0.6; - - // B: Smoother transition to zero (lowers contrast, smoothing out corners). [Recommended] - float f = max(radius2 - vv, 0.0); - return f * f * f * max((vn - bias) / (epsilon + vv), 0.0); - - // C: Medium contrast (which looks better at high radii), no division. Note that the - // contribution still falls off with radius^2, but we've adjusted the rate in a way that is - // more computationally efficient and happens to be aesthetically pleasing. - // return 4.0 * max(1.0 - vv * invRadius2, 0.0) * max(vn - bias, 0.0); - - // D: Low contrast, no division operation - // return 2.0 * float(vv < radius * radius) * max(vn - bias, 0.0); -} - -void main() { - // Pixel being shaded - ivec2 ssC = ivec2(gl_FragCoord.xy); - - // World space point being shaded - vec3 C = getPosition(ssC); - - /* - if (C.z <= -camera_z_far*0.999) { - // We're on the skybox - visibility=1.0; - return; - } - */ - - //visibility=-C.z/camera_z_far; - //return; -#if 0 - vec3 n_C = texelFetch(source_normal,ssC,0).rgb * 2.0 - 1.0; -#else - vec3 n_C = reconstructCSFaceNormal(C); - n_C = -n_C; -#endif - - // Hash function used in the HPG12 AlchemyAO paper - float randomPatternRotationAngle = mod(float((3 * ssC.x ^ ssC.y + ssC.x * ssC.y) * 10), TWO_PI); - - // Reconstruct normals from positions. These will lead to 1-pixel black lines - // at depth discontinuities, however the blur will wipe those out so they are not visible - // in the final image. - - // Choose the screen-space sample radius - // proportional to the projected area of the sphere -#ifdef USE_ORTHOGONAL_PROJECTION - float ssDiskRadius = -proj_scale * radius; -#else - float ssDiskRadius = -proj_scale * radius / C.z; -#endif - float sum = 0.0; - for (int i = 0; i < NUM_SAMPLES; ++i) { - sum += sampleAO(ssC, C, n_C, ssDiskRadius, radius, i, randomPatternRotationAngle); - } - - float A = max(0.0, 1.0 - sum * intensity_div_r6 * (5.0 / float(NUM_SAMPLES))); - -#ifdef ENABLE_RADIUS2 - - //go again for radius2 - randomPatternRotationAngle = mod(float((5 * ssC.x ^ ssC.y + ssC.x * ssC.y) * 11), TWO_PI); - - // Reconstruct normals from positions. These will lead to 1-pixel black lines - // at depth discontinuities, however the blur will wipe those out so they are not visible - // in the final image. - - // Choose the screen-space sample radius - // proportional to the projected area of the sphere - ssDiskRadius = -proj_scale * radius2 / C.z; - - sum = 0.0; - for (int i = 0; i < NUM_SAMPLES; ++i) { - sum += sampleAO(ssC, C, n_C, ssDiskRadius, radius2, i, randomPatternRotationAngle); - } - - A = min(A, max(0.0, 1.0 - sum * intensity_div_r62 * (5.0 / float(NUM_SAMPLES)))); -#endif - // Bilateral box-filter over a quad for free, respecting depth edges - // (the difference that this makes is subtle) - if (abs(dFdx(C.z)) < 0.02) { - A -= dFdx(A) * (float(ssC.x & 1) - 0.5); - } - if (abs(dFdy(C.z)) < 0.02) { - A -= dFdy(A) * (float(ssC.y & 1) - 0.5); - } - - visibility = A; -} |