/**
* Adaptation of SMAA (Enhanced Subpixel Morphological Antialiasing)
* for FlightGear.
* See http://www.iryoku.com/smaa/ for details.
* Licensed under the MIT license, see below.
*/
/**
* Copyright (C) 2013 Jorge Jimenez (jorge@iryoku.com)
* Copyright (C) 2013 Jose I. Echevarria (joseignacioechevarria@gmail.com)
* Copyright (C) 2013 Belen Masia (bmasia@unizar.es)
* Copyright (C) 2013 Fernando Navarro (fernandn@microsoft.com)
* Copyright (C) 2013 Diego Gutierrez (diegog@unizar.es)
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is furnished to
* do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software. As clarification, there
* is no requirement that the copyright notice and permission be included in
* binary distributions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#version 330 core
layout(location = 0) out vec4 fragColor;
in vec2 texcoord;
in vec2 pixcoord;
in vec4 v_offset[3];
uniform sampler2D edges_tex;
uniform sampler2D area_tex;
uniform sampler2D search_tex;
uniform vec4 fg_Viewport;
//------------------------------------------------------------------------------
#define SMAA_THRESHOLD 0.1
#define SMAA_MAX_SEARCH_STEPS_DIAG 8
#define SMAA_CORNER_ROUNDING 25
#define SMAA_AREATEX_MAX_DISTANCE 16
#define SMAA_AREATEX_MAX_DISTANCE_DIAG 20
#define SMAA_AREATEX_PIXEL_SIZE (1.0 / vec2(160.0, 560.0))
#define SMAA_AREATEX_SUBTEX_SIZE (1.0 / 7.0)
#define SMAA_SEARCHTEX_SIZE vec2(66.0, 33.0)
#define SMAA_SEARCHTEX_PACKED_SIZE vec2(64.0, 16.0)
#define SMAA_CORNER_ROUNDING_NORM (float(SMAA_CORNER_ROUNDING) / 100.0)
#define SMAA_AREATEX_SELECT(sample) sample.rg
#define SMAA_SEARCHTEX_SELECT(sample) sample.r
//------------------------------------------------------------------------------
#define mad(a, b, c) (a * b + c)
#define SMAA_RT_METRICS vec4(1.0 / fg_Viewport.z, 1.0 / fg_Viewport.w, fg_Viewport.z, fg_Viewport.w)
#define saturate(a) clamp(a, 0.0, 1.0)
#define round(v) floor(v + 0.5)
#define SMAASampleLevelZeroOffset(tex, coord, offset) textureLodOffset(tex, coord, 0.0, offset)
/**
* Conditional move:
*/
void SMAAMovc(bvec2 cond, inout vec2 variable, vec2 value) {
if (cond.x) variable.x = value.x;
if (cond.y) variable.y = value.y;
}
void SMAAMovc(bvec4 cond, inout vec4 variable, vec4 value) {
SMAAMovc(cond.xy, variable.xy, value.xy);
SMAAMovc(cond.zw, variable.zw, value.zw);
}
//-----------------------------------------------------------------------------
// Diagonal Search Functions
/**
* Allows to decode two binary values from a bilinear-filtered access.
*/
vec2 SMAADecodeDiagBilinearAccess(vec2 e) {
// Bilinear access for fetching 'e' have a 0.25 offset, and we are
// interested in the R and G edges:
//
// +---G---+-------+
// | x o R x |
// +-------+-------+
//
// Then, if one of these edge is enabled:
// Red: (0.75 * X + 0.25 * 1) => 0.25 or 1.0
// Green: (0.75 * 1 + 0.25 * X) => 0.75 or 1.0
//
// This function will unpack the values (mad + mul + round):
// wolframalpha.com: round(x * abs(5 * x - 5 * 0.75)) plot 0 to 1
e.r = e.r * abs(5.0 * e.r - 5.0 * 0.75);
return round(e);
}
vec4 SMAADecodeDiagBilinearAccess(vec4 e) {
e.rb = e.rb * abs(5.0 * e.rb - 5.0 * 0.75);
return round(e);
}
/**
* These functions allows to perform diagonal pattern searches.
*/
vec2 SMAASearchDiag1(sampler2D edgesTex, vec2 texcoord, vec2 dir, out vec2 e) {
vec4 coord = vec4(texcoord, -1.0, 1.0);
vec3 t = vec3(SMAA_RT_METRICS.xy, 1.0);
while (coord.z < float(SMAA_MAX_SEARCH_STEPS_DIAG - 1) &&
coord.w > 0.9) {
coord.xyz = mad(t, vec3(dir, 1.0), coord.xyz);
e = textureLod(edgesTex, coord.xy, 0.0).rg;
coord.w = dot(e, vec2(0.5, 0.5));
}
return coord.zw;
}
vec2 SMAASearchDiag2(sampler2D edgesTex, vec2 texcoord, vec2 dir, out vec2 e) {
vec4 coord = vec4(texcoord, -1.0, 1.0);
coord.x += 0.25 * SMAA_RT_METRICS.x; // See @SearchDiag2Optimization
vec3 t = vec3(SMAA_RT_METRICS.xy, 1.0);
while (coord.z < float(SMAA_MAX_SEARCH_STEPS_DIAG - 1) &&
coord.w > 0.9) {
coord.xyz = mad(t, vec3(dir, 1.0), coord.xyz);
// @SearchDiag2Optimization
// Fetch both edges at once using bilinear filtering:
e = textureLod(edgesTex, coord.xy, 0.0).rg;
e = SMAADecodeDiagBilinearAccess(e);
// Non-optimized version:
// e.g = SMAASampleLevelZero(edgesTex, coord.xy).g;
// e.r = SMAASampleLevelZeroOffset(edgesTex, coord.xy, int2(1, 0)).r;
coord.w = dot(e, vec2(0.5, 0.5));
}
return coord.zw;
}
/**
* Similar to SMAAArea, this calculates the area corresponding to a certain
* diagonal distance and crossing edges 'e'.
*/
vec2 SMAAAreaDiag(sampler2D areaTex, vec2 dist, vec2 e, float offset) {
vec2 texcoord = mad(vec2(SMAA_AREATEX_MAX_DISTANCE_DIAG, SMAA_AREATEX_MAX_DISTANCE_DIAG), e, dist);
// We do a scale and bias for mapping to texel space:
texcoord = mad(SMAA_AREATEX_PIXEL_SIZE, texcoord, 0.5 * SMAA_AREATEX_PIXEL_SIZE);
// Diagonal areas are on the second half of the texture:
texcoord.x += 0.5;
// Move to proper place, according to the subpixel offset:
texcoord.y += SMAA_AREATEX_SUBTEX_SIZE * offset;
// Do it!
return SMAA_AREATEX_SELECT(textureLod(areaTex, texcoord, 0.0));
}
/**
* This searches for diagonal patterns and returns the corresponding weights.
*/
vec2 SMAACalculateDiagWeights(sampler2D edgesTex, sampler2D areaTex, vec2 texcoord, vec2 e, vec4 subsampleIndices) {
vec2 weights = vec2(0.0, 0.0);
// Search for the line ends:
vec4 d;
vec2 end;
if (e.r > 0.0) {
d.xz = SMAASearchDiag1(edgesTex, texcoord, vec2(-1.0, 1.0), end);
d.x += float(end.y > 0.9);
} else
d.xz = vec2(0.0, 0.0);
d.yw = SMAASearchDiag1(edgesTex, texcoord, vec2(1.0, -1.0), end);
if (d.x + d.y > 2.0) { // d.x + d.y + 1 > 3
// Fetch the crossing edges:
vec4 coords = mad(vec4(-d.x + 0.25, d.x, d.y, -d.y - 0.25), SMAA_RT_METRICS.xyxy, texcoord.xyxy);
vec4 c;
c.xy = SMAASampleLevelZeroOffset(edgesTex, coords.xy, ivec2(-1, 0)).rg;
c.zw = SMAASampleLevelZeroOffset(edgesTex, coords.zw, ivec2( 1, 0)).rg;
c.yxwz = SMAADecodeDiagBilinearAccess(c.xyzw);
// Non-optimized version:
// vec4 coords = mad(float4(-d.x, d.x, d.y, -d.y), SMAA_RT_METRICS.xyxy, texcoord.xyxy);
// vec4 c;
// c.x = SMAASampleLevelZeroOffset(edgesTex, coords.xy, ivec2(-1, 0)).g;
// c.y = SMAASampleLevelZeroOffset(edgesTex, coords.xy, ivec2( 0, 0)).r;
// c.z = SMAASampleLevelZeroOffset(edgesTex, coords.zw, ivec2( 1, 0)).g;
// c.w = SMAASampleLevelZeroOffset(edgesTex, coords.zw, ivec2( 1, -1)).r;
// Merge crossing edges at each side into a single value:
vec2 cc = mad(vec2(2.0, 2.0), c.xz, c.yw);
// Remove the crossing edge if we didn't found the end of the line:
SMAAMovc(bvec2(step(0.9, d.zw)), cc, vec2(0.0, 0.0));
// Fetch the areas for this line:
weights += SMAAAreaDiag(areaTex, d.xy, cc, subsampleIndices.z);
}
// Search for the line ends:
d.xz = SMAASearchDiag2(edgesTex, texcoord, vec2(-1.0, -1.0), end);
if (SMAASampleLevelZeroOffset(edgesTex, texcoord, ivec2(1, 0)).r > 0.0) {
d.yw = SMAASearchDiag2(edgesTex, texcoord, vec2(1.0, 1.0), end);
d.y += float(end.y > 0.9);
} else
d.yw = vec2(0.0, 0.0);
if (d.x + d.y > 2.0) { // d.x + d.y + 1 > 3
// Fetch the crossing edges:
vec4 coords = mad(vec4(-d.x, -d.x, d.y, d.y), SMAA_RT_METRICS.xyxy, texcoord.xyxy);
vec4 c;
c.x = SMAASampleLevelZeroOffset(edgesTex, coords.xy, ivec2(-1, 0)).g;
c.y = SMAASampleLevelZeroOffset(edgesTex, coords.xy, ivec2( 0, -1)).r;
c.zw = SMAASampleLevelZeroOffset(edgesTex, coords.zw, ivec2( 1, 0)).gr;
vec2 cc = mad(vec2(2.0, 2.0), c.xz, c.yw);
// Remove the crossing edge if we didn't found the end of the line:
SMAAMovc(bvec2(step(0.9, d.zw)), cc, vec2(0.0, 0.0));
// Fetch the areas for this line:
weights += SMAAAreaDiag(areaTex, d.xy, cc, subsampleIndices.w).gr;
}
return weights;
}
//-----------------------------------------------------------------------------
// Horizontal/Vertical Search Functions
/**
* This allows to determine how much length should we add in the last step
* of the searches. It takes the bilinearly interpolated edge (see
* @PSEUDO_GATHER4), and adds 0, 1 or 2, depending on which edges and
* crossing edges are active.
*/
float SMAASearchLength(sampler2D searchTex, vec2 e, float offset) {
// The texture is flipped vertically, with left and right cases taking half
// of the space horizontally:
vec2 scale = SMAA_SEARCHTEX_SIZE * vec2(0.5, -1.0);
vec2 bias = SMAA_SEARCHTEX_SIZE * vec2(offset, 1.0);
// Scale and bias to access texel centers:
scale += vec2(-1.0, 1.0);
bias += vec2( 0.5, -0.5);
// Convert from pixel coordinates to texcoords:
// (We use SMAA_SEARCHTEX_PACKED_SIZE because the texture is cropped)
scale *= 1.0 / SMAA_SEARCHTEX_PACKED_SIZE;
bias *= 1.0 / SMAA_SEARCHTEX_PACKED_SIZE;
// Lookup the search texture:
return SMAA_SEARCHTEX_SELECT(textureLod(searchTex, mad(scale, e, bias), 0.0));
}
/**
* Horizontal/vertical search functions for the 2nd pass.
*/
float SMAASearchXLeft(sampler2D edgesTex, sampler2D searchTex, vec2 texcoord, float end) {
/**
* @PSEUDO_GATHER4
* This texcoord has been offset by (-0.25, -0.125) in the vertex shader to
* sample between edge, thus fetching four edges in a row.
* Sampling with different offsets in each direction allows to disambiguate
* which edges are active from the four fetched ones.
*/
vec2 e = vec2(0.0, 1.0);
while (texcoord.x > end &&
e.g > 0.8281 && // Is there some edge not activated?
e.r == 0.0) { // Or is there a crossing edge that breaks the line?
e = textureLod(edgesTex, texcoord, 0.0).rg;
texcoord = mad(-vec2(2.0, 0.0), SMAA_RT_METRICS.xy, texcoord);
}
float offset = mad(-(255.0 / 127.0), SMAASearchLength(searchTex, e, 0.0), 3.25);
return mad(SMAA_RT_METRICS.x, offset, texcoord.x);
// Non-optimized version:
// We correct the previous (-0.25, -0.125) offset we applied:
// texcoord.x += 0.25 * SMAA_RT_METRICS.x;
// The searches are bias by 1, so adjust the coords accordingly:
// texcoord.x += SMAA_RT_METRICS.x;
// Disambiguate the length added by the last step:
// texcoord.x += 2.0 * SMAA_RT_METRICS.x; // Undo last step
// texcoord.x -= SMAA_RT_METRICS.x * (255.0 / 127.0) * SMAASearchLength(SMAATexturePass2D(searchTex), e, 0.0);
// return mad(SMAA_RT_METRICS.x, offset, texcoord.x);
}
float SMAASearchXRight(sampler2D edgesTex, sampler2D searchTex, vec2 texcoord, float end) {
vec2 e = vec2(0.0, 1.0);
while (texcoord.x < end &&
e.g > 0.8281 && // Is there some edge not activated?
e.r == 0.0) { // Or is there a crossing edge that breaks the line?
e = textureLod(edgesTex, texcoord, 0.0).rg;
texcoord = mad(vec2(2.0, 0.0), SMAA_RT_METRICS.xy, texcoord);
}
float offset = mad(-(255.0 / 127.0), SMAASearchLength(searchTex, e, 0.5), 3.25);
return mad(-SMAA_RT_METRICS.x, offset, texcoord.x);
}
float SMAASearchYUp(sampler2D edgesTex, sampler2D searchTex, vec2 texcoord, float end) {
vec2 e = vec2(1.0, 0.0);
while (texcoord.y > end &&
e.r > 0.8281 && // Is there some edge not activated?
e.g == 0.0) { // Or is there a crossing edge that breaks the line?
e = textureLod(edgesTex, texcoord, 0.0).rg;
texcoord = mad(-vec2(0.0, 2.0), SMAA_RT_METRICS.xy, texcoord);
}
float offset = mad(-(255.0 / 127.0), SMAASearchLength(searchTex, e.gr, 0.0), 3.25);
return mad(SMAA_RT_METRICS.y, offset, texcoord.y);
}
float SMAASearchYDown(sampler2D edgesTex, sampler2D searchTex, vec2 texcoord, float end) {
vec2 e = vec2(1.0, 0.0);
while (texcoord.y < end &&
e.r > 0.8281 && // Is there some edge not activated?
e.g == 0.0) { // Or is there a crossing edge that breaks the line?
e = textureLod(edgesTex, texcoord, 0.0).rg;
texcoord = mad(vec2(0.0, 2.0), SMAA_RT_METRICS.xy, texcoord);
}
float offset = mad(-(255.0 / 127.0), SMAASearchLength(searchTex, e.gr, 0.5), 3.25);
return mad(-SMAA_RT_METRICS.y, offset, texcoord.y);
}
/**
* Ok, we have the distance and both crossing edges. So, what are the areas
* at each side of current edge?
*/
vec2 SMAAArea(sampler2D area_tex, vec2 dist, float e1, float e2, float offset) {
// Rounding prevents precision errors of bilinear filtering:
vec2 texcoord = mad(vec2(SMAA_AREATEX_MAX_DISTANCE, SMAA_AREATEX_MAX_DISTANCE), round(4.0 * vec2(e1, e2)), dist);
// We do a scale and bias for mapping to texel space:
texcoord = mad(SMAA_AREATEX_PIXEL_SIZE, texcoord, 0.5 * SMAA_AREATEX_PIXEL_SIZE);
// Move to proper place, according to the subpixel offset:
texcoord.y = mad(SMAA_AREATEX_SUBTEX_SIZE, offset, texcoord.y);
// Do it!
return SMAA_AREATEX_SELECT(textureLod(area_tex, texcoord, 0.0));
}
//-----------------------------------------------------------------------------
// Corner Detection Functions
void SMAADetectHorizontalCornerPattern(sampler2D edgesTex, inout vec2 weights, vec4 texcoord, vec2 d) {
#if !defined(SMAA_DISABLE_CORNER_DETECTION)
vec2 leftRight = step(d.xy, d.yx);
vec2 rounding = (1.0 - SMAA_CORNER_ROUNDING_NORM) * leftRight;
rounding /= leftRight.x + leftRight.y; // Reduce blending for pixels in the center of a line.
vec2 factor = vec2(1.0, 1.0);
factor.x -= rounding.x * SMAASampleLevelZeroOffset(edgesTex, texcoord.xy, ivec2(0, 1)).r;
factor.x -= rounding.y * SMAASampleLevelZeroOffset(edgesTex, texcoord.zw, ivec2(1, 1)).r;
factor.y -= rounding.x * SMAASampleLevelZeroOffset(edgesTex, texcoord.xy, ivec2(0, -2)).r;
factor.y -= rounding.y * SMAASampleLevelZeroOffset(edgesTex, texcoord.zw, ivec2(1, -2)).r;
weights *= saturate(factor);
#endif
}
void SMAADetectVerticalCornerPattern(sampler2D edgesTex, inout vec2 weights, vec4 texcoord, vec2 d) {
#if !defined(SMAA_DISABLE_CORNER_DETECTION)
vec2 leftRight = step(d.xy, d.yx);
vec2 rounding = (1.0 - SMAA_CORNER_ROUNDING_NORM) * leftRight;
rounding /= leftRight.x + leftRight.y;
vec2 factor = vec2(1.0, 1.0);
factor.x -= rounding.x * SMAASampleLevelZeroOffset(edgesTex, texcoord.xy, ivec2( 1, 0)).g;
factor.x -= rounding.y * SMAASampleLevelZeroOffset(edgesTex, texcoord.zw, ivec2( 1, 1)).g;
factor.y -= rounding.x * SMAASampleLevelZeroOffset(edgesTex, texcoord.xy, ivec2(-2, 0)).g;
factor.y -= rounding.y * SMAASampleLevelZeroOffset(edgesTex, texcoord.zw, ivec2(-2, 1)).g;
weights *= saturate(factor);
#endif
}
//-----------------------------------------------------------------------------
// Blending Weight Calculation Pixel Shader (Second Pass)
void main()
{
vec4 subsampleIndices = vec4(0.0); // Just pass zero for SMAA 1x, see @SUBSAMPLE_INDICES.
vec4 weights = vec4(0.0, 0.0, 0.0, 0.0);
vec2 e = texture(edges_tex, texcoord).rg;
if (e.g > 0.0) { // Edge at north
#if !defined(SMAA_DISABLE_DIAG_DETECTION)
// Diagonals have both north and west edges, so searching for them in
// one of the boundaries is enough.
weights.rg = SMAACalculateDiagWeights(edges_tex, area_tex, texcoord, e, subsampleIndices);
// We give priority to diagonals, so if we find a diagonal we skip
// horizontal/vertical processing.
if (weights.r == -weights.g) { // weights.r + weights.g == 0.0
#endif
vec2 d;
// Find the distance to the left:
vec3 coords;
coords.x = SMAASearchXLeft(edges_tex, search_tex, v_offset[0].xy, v_offset[2].x);
coords.y = v_offset[1].y; // v_offset[1].y = texcoord.y - 0.25 * SMAA_RT_METRICS.y (@CROSSING_OFFSET)
d.x = coords.x;
// Now fetch the left crossing edges, two at a time using bilinear
// filtering. Sampling at -0.25 (see @CROSSING_OFFSET) enables to
// discern what value each edge has:
float e1 = textureLod(edges_tex, coords.xy, 0.0).r;
// Find the distance to the right:
coords.z = SMAASearchXRight(edges_tex, search_tex, v_offset[0].zw, v_offset[2].y);
d.y = coords.z;
// We want the distances to be in pixel units (doing this here allow to
// better interleave arithmetic and memory accesses):
d = abs(round(mad(SMAA_RT_METRICS.zz, d, -pixcoord.xx)));
// SMAAArea below needs a sqrt, as the areas texture is compressed
// quadratically:
vec2 sqrt_d = sqrt(d);
// Fetch the right crossing edges:
float e2 = SMAASampleLevelZeroOffset(edges_tex, coords.zy, ivec2(1, 0)).r;
// Ok, we know how this pattern looks like, now it is time for getting
// the actual area:
weights.rg = SMAAArea(area_tex, sqrt_d, e1, e2, subsampleIndices.y);
// Fix corners:
coords.y = texcoord.y;
SMAADetectHorizontalCornerPattern(edges_tex, weights.rg, coords.xyzy, d);
#if !defined(SMAA_DISABLE_DIAG_DETECTION)
} else
e.r = 0.0; // Skip vertical processing.
#endif
}
if (e.r > 0.0) { // Edge at west
vec2 d;
// Find the distance to the top:
vec3 coords;
coords.y = SMAASearchYUp(edges_tex, search_tex, v_offset[1].xy, v_offset[2].z);
coords.x = v_offset[0].x; // v_offset[1].x = texcoord.x - 0.25 * SMAA_RT_METRICS.x;
d.x = coords.y;
// Fetch the top crossing edges:
float e1 = textureLod(edges_tex, coords.xy, 0.0).g;
// Find the distance to the bottom:
coords.z = SMAASearchYDown(edges_tex, search_tex, v_offset[1].zw, v_offset[2].w);
d.y = coords.z;
// We want the distances to be in pixel units:
d = abs(round(mad(SMAA_RT_METRICS.ww, d, -pixcoord.yy)));
// SMAAArea below needs a sqrt, as the areas texture is compressed
// quadratically:
vec2 sqrt_d = sqrt(d);
// Fetch the bottom crossing edges:
float e2 = SMAASampleLevelZeroOffset(edges_tex, coords.xz, ivec2(0, 1)).g;
// Get the area for this direction:
weights.ba = SMAAArea(area_tex, sqrt_d, e1, e2, subsampleIndices.x);
// Fix corners:
coords.x = texcoord.x;
SMAADetectVerticalCornerPattern(edges_tex, weights.ba, coords.xyxz, d);
}
fragColor = weights;
}