147 lines
3.7 KiB
GLSL
147 lines
3.7 KiB
GLSL
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/* Infinite grid
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* Clément Foucault */
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in vec3 wPos;
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out vec4 FragColor;
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uniform mat4 ProjectionMatrix;
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uniform vec3 cameraPos;
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uniform vec3 eye;
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uniform vec4 gridSettings;
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uniform float gridOneOverLogSubdiv;
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#define gridDistance gridSettings.x
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#define gridResolution gridSettings.y
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#define gridScale gridSettings.z
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#define gridSubdiv gridSettings.w
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uniform int gridFlag;
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#define AXIS_X (1 << 0)
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#define AXIS_Y (1 << 1)
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#define AXIS_Z (1 << 2)
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#define GRID (1 << 3)
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#define PLANE_XY (1 << 4)
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#define PLANE_XZ (1 << 5)
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#define PLANE_YZ (1 << 6)
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#define GRID_LINE_SMOOTH 1.15
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float grid(vec3 uv, vec3 fwidthCos, float grid_size)
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{
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float half_size = grid_size / 2.0;
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/* triangular wave pattern, amplitude is [0, grid_size] */
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vec3 grid_domain = abs(mod(uv + half_size, grid_size) - half_size);
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/* modulate by the absolute rate of change of the uvs
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* (make lines have the same width under perspective) */
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grid_domain /= fwidthCos;
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/* collapse waves and normalize */
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grid_domain.x = min(grid_domain.x, min(grid_domain.y, grid_domain.z)) / grid_size;
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return 1.0 - smoothstep(0.0, GRID_LINE_SMOOTH / grid_size, grid_domain.x);
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}
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float axis(float u, float fwidthU, float line_size)
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{
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float axis_domain = abs(u);
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/* modulate by the absolute rate of change of the uvs
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* (make line have the same width under perspective) */
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axis_domain /= fwidthU;
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return 1.0 - smoothstep(0.0, GRID_LINE_SMOOTH, axis_domain - line_size);
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}
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void main()
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{
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vec3 fwidthCos = fwidth(wPos);
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float dist, fade;
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/* if persp */
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if (ProjectionMatrix[3][3] == 0.0) {
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vec3 viewvec = cameraPos - wPos;
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dist = length(viewvec);
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viewvec /= dist;
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float angle;
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if ((gridFlag & PLANE_XZ) > 0)
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angle = viewvec.y;
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else if ((gridFlag & PLANE_YZ) > 0)
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angle = viewvec.x;
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else
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angle = viewvec.z;
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angle = 1.0 - abs(angle);
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fade = 1.0 - angle * angle;
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fade *= 1.0 - smoothstep(0.0, gridDistance, dist - gridDistance);
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}
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else {
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dist = abs(gl_FragCoord.z * 2.0 - 1.0);
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fade = 1.0 - smoothstep(0.0, 0.5, dist - 0.5);
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dist = 1.0; /* avoid branch after */
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if ((gridFlag & PLANE_XY) > 0) {
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float angle = 1.0 - abs(eye.z);
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fade *= 1.0 - angle * angle * angle;
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dist = 1.0 + angle * 2.0;
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}
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}
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if ((gridFlag & GRID) > 0) {
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float grid_res = log(dist * gridResolution) * gridOneOverLogSubdiv;
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float blend = fract(-max(grid_res, 0.0));
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float lvl = floor(grid_res);
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/* from smallest to biggest */
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float scaleA = gridScale * pow(gridSubdiv, max(lvl - 1.0, 0.0));
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float scaleB = gridScale * pow(gridSubdiv, max(lvl + 0.0, 0.0));
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float scaleC = gridScale * pow(gridSubdiv, max(lvl + 1.0, 1.0));
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float gridA = grid(wPos, fwidthCos, scaleA);
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float gridB = grid(wPos, fwidthCos, scaleB);
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float gridC = grid(wPos, fwidthCos, scaleC);
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FragColor = vec4(colorGrid.rgb, gridA * blend);
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FragColor = mix(FragColor, vec4(mix(colorGrid.rgb, colorGridEmphasise.rgb, blend), 1.0), gridB);
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FragColor = mix(FragColor, vec4(colorGridEmphasise.rgb, 1.0), gridC);
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}
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else {
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FragColor = vec4(colorGrid.rgb, 0.0);
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}
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if ((gridFlag & AXIS_X) > 0) {
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float xAxis;
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if ((gridFlag & PLANE_XZ) > 0) {
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xAxis = axis(wPos.z, fwidthCos.z, 0.1);
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}
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else {
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xAxis = axis(wPos.y, fwidthCos.y, 0.1);
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}
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FragColor = mix(FragColor, colorGridAxisX, xAxis);
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}
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if ((gridFlag & AXIS_Y) > 0) {
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float yAxis;
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if ((gridFlag & PLANE_YZ) > 0) {
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yAxis = axis(wPos.z, fwidthCos.z, 0.1);
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}
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else {
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yAxis = axis(wPos.x, fwidthCos.x, 0.1);
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}
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FragColor = mix(FragColor, colorGridAxisY, yAxis);
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}
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if ((gridFlag & AXIS_Z) > 0) {
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float zAxis;
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if ((gridFlag & PLANE_YZ) > 0) {
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zAxis = axis(wPos.y, fwidthCos.y, 0.1);
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}
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else {
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zAxis = axis(wPos.x, fwidthCos.x, 0.1);
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}
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FragColor = mix(FragColor, colorGridAxisZ, zAxis);
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}
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FragColor.a *= fade;
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} |