diff options
Diffstat (limited to 'source/blender/draw/engines/gpencil/shaders/gpencil_stroke_geom.glsl')
-rw-r--r-- | source/blender/draw/engines/gpencil/shaders/gpencil_stroke_geom.glsl | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/source/blender/draw/engines/gpencil/shaders/gpencil_stroke_geom.glsl b/source/blender/draw/engines/gpencil/shaders/gpencil_stroke_geom.glsl new file mode 100644 index 00000000000..0bcfe8cddb7 --- /dev/null +++ b/source/blender/draw/engines/gpencil/shaders/gpencil_stroke_geom.glsl @@ -0,0 +1,208 @@ +uniform mat4 ModelViewProjectionMatrix; +uniform vec2 Viewport; +uniform int xraymode; +uniform int color_type; + +layout(lines_adjacency) in; +layout(triangle_strip, max_vertices = 13) out; + +in vec4 finalColor[4]; +in float finalThickness[4]; +in vec2 finaluvdata[4]; + +out vec4 mColor; +out vec2 mTexCoord; +out float uvfac; + +#define GP_XRAY_FRONT 0 +#define GP_XRAY_3DSPACE 1 +#define GP_XRAY_BACK 2 + +/* keep this list synchronized with list in gpencil_engine.h */ +#define GPENCIL_COLOR_SOLID 0 +#define GPENCIL_COLOR_TEXTURE 1 +#define GPENCIL_COLOR_PATTERN 2 + +/* project 3d point to 2d on screen space */ +vec2 toScreenSpace(vec4 vertex) +{ + return vec2(vertex.xy / vertex.w) * Viewport; +} + +/* get zdepth value */ +float getZdepth(vec4 point) +{ + if (xraymode == GP_XRAY_FRONT) { + return 0.0; + } + if (xraymode == GP_XRAY_3DSPACE) { + return (point.z / point.w); + } + if (xraymode == GP_XRAY_BACK) { + return 0.999999; + } + + /* in front by default */ + return 0.0; +} +void main(void) +{ + float MiterLimit = 0.75; + uvfac = 0; + + /* receive 4 points */ + vec4 P0 = gl_in[0].gl_Position; + vec4 P1 = gl_in[1].gl_Position; + vec4 P2 = gl_in[2].gl_Position; + vec4 P3 = gl_in[3].gl_Position; + + /* get the four vertices passed to the shader */ + vec2 sp0 = toScreenSpace(P0); // start of previous segment + vec2 sp1 = toScreenSpace(P1); // end of previous segment, start of current segment + vec2 sp2 = toScreenSpace(P2); // end of current segment, start of next segment + vec2 sp3 = toScreenSpace(P3); // end of next segment + + /* culling outside viewport */ + vec2 area = Viewport * 4.0; + if (sp1.x < -area.x || sp1.x > area.x) return; + if (sp1.y < -area.y || sp1.y > area.y) return; + if (sp2.x < -area.x || sp2.x > area.x) return; + if (sp2.y < -area.y || sp2.y > area.y) return; + + /* determine the direction of each of the 3 segments (previous, current, next) */ + vec2 v0 = normalize(sp1 - sp0); + vec2 v1 = normalize(sp2 - sp1); + vec2 v2 = normalize(sp3 - sp2); + + /* determine the normal of each of the 3 segments (previous, current, next) */ + vec2 n0 = vec2(-v0.y, v0.x); + vec2 n1 = vec2(-v1.y, v1.x); + vec2 n2 = vec2(-v2.y, v2.x); + + /* determine miter lines by averaging the normals of the 2 segments */ + vec2 miter_a = normalize(n0 + n1); // miter at start of current segment + vec2 miter_b = normalize(n1 + n2); // miter at end of current segment + + /* determine the length of the miter by projecting it onto normal and then inverse it */ + float an1 = dot(miter_a, n1); + float bn1 = dot(miter_b, n2); + if (an1 == 0) an1 = 1; + if (bn1 == 0) bn1 = 1; + float length_a = finalThickness[1] / an1; + float length_b = finalThickness[2] / bn1; + if (length_a <= 0.0) length_a = 0.01; + if (length_b <= 0.0) length_b = 0.01; + + /* prevent excessively long miters at sharp corners */ + if (dot(v0, v1) < -MiterLimit) { + miter_a = n1; + length_a = finalThickness[1]; + + /* close the gap */ + if (dot(v0, n1) > 0) { + mTexCoord = vec2(0, 0); + mColor = finalColor[1]; + gl_Position = vec4((sp1 + finalThickness[1] * n0) / Viewport, getZdepth(P1), 1.0); + EmitVertex(); + + mTexCoord = vec2(0, 0); + mColor = finalColor[1]; + gl_Position = vec4((sp1 + finalThickness[1] * n1) / Viewport, getZdepth(P1), 1.0); + EmitVertex(); + + mTexCoord = vec2(0, 0.5); + mColor = finalColor[1]; + gl_Position = vec4(sp1 / Viewport, getZdepth(P1), 1.0); + EmitVertex(); + + EndPrimitive(); + } + else { + mTexCoord = vec2(0, 1); + mColor = finalColor[1]; + gl_Position = vec4((sp1 - finalThickness[1] * n1) / Viewport, getZdepth(P1), 1.0); + EmitVertex(); + + mTexCoord = vec2(0, 1); + mColor = finalColor[1]; + gl_Position = vec4((sp1 - finalThickness[1] * n0) / Viewport, getZdepth(P1), 1.0); + EmitVertex(); + + mTexCoord = vec2(0, 0.5); + mColor = finalColor[1]; + gl_Position = vec4(sp1 / Viewport, getZdepth(P1), 1.0); + EmitVertex(); + + EndPrimitive(); + } + } + + if (dot(v1, v2) < -MiterLimit) { + miter_b = n1; + length_b = finalThickness[2]; + } + + /* generate the start endcap (alpha < 0 used as endcap flag)*/ + if ((P0 == P2) && (color_type == GPENCIL_COLOR_SOLID)){ + mTexCoord = vec2(2, 1); + mColor = vec4(finalColor[1].rgb, finalColor[1].a * -1.0) ; + vec2 svn1 = normalize(sp1 - sp2) * length_a * 4.0; + gl_Position = vec4((sp1 + svn1) / Viewport, getZdepth(P1), 1.0); + EmitVertex(); + + mTexCoord = vec2(0, 0); + mColor = vec4(finalColor[1].rgb, finalColor[1].a * -1.0) ; + gl_Position = vec4((sp1 - (length_a * 2.0) * miter_a) / Viewport, getZdepth(P1), 1.0); + EmitVertex(); + + mTexCoord = vec2(0, 2); + mColor = vec4(finalColor[1].rgb, finalColor[1].a * -1.0) ; + gl_Position = vec4((sp1 + (length_a * 2.0) * miter_a) / Viewport, getZdepth(P1), 1.0); + EmitVertex(); + } + + /* generate the triangle strip */ + mTexCoord = (color_type == GPENCIL_COLOR_SOLID) ? vec2(0, 0) : vec2(finaluvdata[1].x, 0); + mColor = finalColor[1]; + gl_Position = vec4((sp1 + length_a * miter_a) / Viewport, getZdepth(P1), 1.0); + EmitVertex(); + + mTexCoord = (color_type == GPENCIL_COLOR_SOLID) ? vec2(0, 1) : vec2(finaluvdata[1].x, 1); + mColor = finalColor[1]; + gl_Position = vec4((sp1 - length_a * miter_a) / Viewport, getZdepth(P1), 1.0); + EmitVertex(); + + mTexCoord = (color_type == GPENCIL_COLOR_SOLID) ? vec2(1, 0) : vec2(finaluvdata[2].x, 0); + mColor = finalColor[2]; + gl_Position = vec4((sp2 + length_b * miter_b) / Viewport, getZdepth(P2), 1.0); + EmitVertex(); + + mTexCoord = (color_type == GPENCIL_COLOR_SOLID) ? vec2(1, 1) : vec2(finaluvdata[2].x, 1); + mColor = finalColor[2]; + gl_Position = vec4((sp2 - length_b * miter_b) / Viewport, getZdepth(P2), 1.0); + EmitVertex(); + + /* generate the end endcap (alpha < 0 used as endcap flag)*/ + if ((P1 == P3) && (color_type == GPENCIL_COLOR_SOLID)){ + mTexCoord = vec2(finaluvdata[2].x, 2); + mColor = vec4(finalColor[2].rgb, finalColor[2].a * -1.0) ; + uvfac = finaluvdata[2].x; + gl_Position = vec4((sp2 + (length_b * 2.0) * miter_b) / Viewport, getZdepth(P2), 1.0); + EmitVertex(); + + mTexCoord = vec2(finaluvdata[2].x, 0); + mColor = vec4(finalColor[2].rgb, finalColor[2].a * -1.0) ; + uvfac = finaluvdata[2].x; + gl_Position = vec4((sp2 - (length_b * 2.0) * miter_b) / Viewport, getZdepth(P2), 1.0); + EmitVertex(); + + mTexCoord = vec2(finaluvdata[2].x + 2, 1); + mColor = vec4(finalColor[2].rgb, finalColor[2].a * -1.0) ; + uvfac = finaluvdata[2].x; + vec2 svn2 = normalize(sp2 - sp1) * length_b * 4.0; + gl_Position = vec4((sp2 + svn2) / Viewport, getZdepth(P2), 1.0); + EmitVertex(); + } + + EndPrimitive(); +} |