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uniform vec4 bokehParams[2];
#define bokeh_rotation bokehParams[0].x
#define bokeh_ratio bokehParams[0].y
#define bokeh_maxsize bokehParams[0].z
uniform sampler2D nearBuffer;
uniform sampler2D farBuffer;
uniform sampler2D cocBuffer;
flat out vec4 color;
flat out float smoothFac;
flat out ivec2 edge;
out vec2 particlecoord;
#define M_PI 3.1415926535897932384626433832795
/* Scatter pass, calculate a triangle covering the CoC. */
void main()
{
ivec2 tex_size = textureSize(cocBuffer, 0);
/* We render to a double width texture so compute
* the target texel size accordingly */
vec2 texel_size = vec2(0.5, 1.0) / vec2(tex_size);
int t_id = gl_VertexID / 3; /* Triangle Id */
ivec2 texelco = ivec2(0);
/* some math to get the target pixel */
texelco.x = t_id % tex_size.x;
texelco.y = t_id / tex_size.x;
vec2 cocs = texelFetch(cocBuffer, texelco, 0).rg;
bool is_near = (cocs.x > cocs.y);
float coc = (is_near) ? cocs.x : cocs.y;
/* Clamp to max size for performance */
coc = min(coc, bokeh_maxsize);
if (coc >= 1.0) {
if (is_near) {
color = texelFetch(nearBuffer, texelco, 0);
}
else {
color = texelFetch(farBuffer, texelco, 0);
}
/* find the area the pixel will cover and divide the color by it */
color.a = 1.0 / (coc * coc * M_PI);
color.rgb *= color.a;
/* Compute edge to discard fragment that does not belong to the other layer. */
edge.x = (is_near) ? 1 : -1;
edge.y = (is_near) ? -tex_size.x + 1 : tex_size.x;
}
else {
/* Don't produce any fragments */
color = vec4(0.0);
gl_Position = vec4(0.0, 0.0, 0.0, 1.0);
return;
}
/* Generate Triangle : less memory fetches from a VBO */
int v_id = gl_VertexID % 3; /* Vertex Id */
/* Extend to cover at least the unit circle */
const float extend = (cos(M_PI / 4.0) + 1.0) * 2.0;
/* Crappy diagram
* ex 1
* | \
* | \
* 1 | \
* | \
* | \
* 0 | x \
* | Circle \
* | Origin \
* -1 0 --------------- 2
* -1 0 1 ex
**/
gl_Position.x = float(v_id / 2) * extend - 1.0; /* int divisor round down */
gl_Position.y = float(v_id % 2) * extend - 1.0;
gl_Position.z = 0.0;
gl_Position.w = 1.0;
/* Generate Triangle */
particlecoord = gl_Position.xy;
gl_Position.xy *= coc * texel_size * vec2(bokeh_ratio, 1.0);
gl_Position.xy -= 1.0 - 0.5 * texel_size; /* NDC Bottom left */
gl_Position.xy += (0.5 + vec2(texelco) * 2.0) * texel_size;
/* Push far plane to left side. */
gl_Position.x += (!is_near) ? 1.0 : 0.0;
/* don't do smoothing for small sprites */
if (coc > 3.0) {
smoothFac = 1.0 - 1.5 / coc;
}
else {
smoothFac = 1.0;
}
int tex_width = textureSize(cocBuffer, 0).x;
}
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