[Bf-blender-cvs] [f883a9c9bbf] greasepencil-refactor: GPencil: Refactor: Add UV / Texture support to strokes

[Clément Foucault]

Commit: f883a9c9bbf83d0bb7a7205e78d274c315762e39
Author: Clément Foucault
Date:   Wed Dec 11 17:18:44 2019 +0100
Branches: greasepencil-refactor
https://developer.blender.org/rBf883a9c9bbf83d0bb7a7205e78d274c315762e39

GPencil: Refactor: Add UV / Texture support to strokes

===================================================================

M	source/blender/draw/engines/gpencil/gpencil_draw_cache_impl.c
M	source/blender/draw/engines/gpencil/shaders/gpencil_vert.glsl

===================================================================

diff --git a/source/blender/draw/engines/gpencil/gpencil_draw_cache_impl.c b/source/blender/draw/engines/gpencil/gpencil_draw_cache_impl.c
index 2d6c64bdd70..630cd55135c 100644
--- a/source/blender/draw/engines/gpencil/gpencil_draw_cache_impl.c
+++ b/source/blender/draw/engines/gpencil/gpencil_draw_cache_impl.c
@@ -67,22 +67,23 @@ static GPUVertBuf *gpencil_dummy_buffer_get(void)
 
 /* MUST match the format below. */
 typedef struct gpStrokeVert {
-  int mat;
+  /** Mat is float because we need to pack other float attribs with it. */
+  float mat, strength;
   /** Position and thickness packed in the same attribute. */
   float pos[3], thickness;
   float col[4];
   /** UV and strength packed in the same attribute. */
-  float uv[2], strength;
+  float uv[2], u_stroke, v_rot;
 } gpStrokeVert;
 
 static GPUVertFormat *gpencil_stroke_format(void)
 {
   static GPUVertFormat format = {0};
   if (format.attr_len == 0) {
-    GPU_vertformat_attr_add(&format, "ma", GPU_COMP_I32, 1, GPU_FETCH_INT);
+    GPU_vertformat_attr_add(&format, "ma", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
     GPU_vertformat_attr_add(&format, "pos", GPU_COMP_F32, 4, GPU_FETCH_FLOAT);
     GPU_vertformat_attr_add(&format, "col", GPU_COMP_F32, 4, GPU_FETCH_FLOAT);
-    GPU_vertformat_attr_add(&format, "uv", GPU_COMP_F32, 3, GPU_FETCH_FLOAT);
+    GPU_vertformat_attr_add(&format, "uv", GPU_COMP_F32, 4, GPU_FETCH_FLOAT);
     /* IMPORTANT: This means having only 4 attributes to fit into opengl limit of 16 attrib. */
     GPU_vertformat_multiload_enable(&format, 4);
   }
@@ -117,6 +118,10 @@ static void gpencil_buffer_add_point(gpStrokeVert *verts,
   copy_v2_v2(verts->uv, pt->uv_fill);
   copy_v4_v4(verts->col, pt->mix_color);
   verts->strength = pt->strength;
+  verts->u_stroke = pt->uv_fac;
+  /* Rotation are in [-90°..90°] range, so we can encode the sign of the angle + the cosine
+   * because the cosine will always be positive. */
+  verts->v_rot = cosf(pt->uv_rot) * signf(pt->uv_rot);
   verts->thickness = gps->thickness * pt->pressure;
   /* Tag endpoint material to -1 so they get discarded by vertex shader. */
   verts->mat = (is_endpoint) ? -1 : (gps->mat_nr % GPENCIL_MATERIAL_BUFFER_LEN);
diff --git a/source/blender/draw/engines/gpencil/shaders/gpencil_vert.glsl b/source/blender/draw/engines/gpencil/shaders/gpencil_vert.glsl
index 051c84ca9a1..26fbbe2fafd 100644
--- a/source/blender/draw/engines/gpencil/shaders/gpencil_vert.glsl
+++ b/source/blender/draw/engines/gpencil/shaders/gpencil_vert.glsl
@@ -12,16 +12,18 @@ uniform float thicknessWorldScale;
 /* Per Layer */
 uniform float thicknessOffset;
 
-in int ma1;
-in int ma2;
+in vec2 ma1;
+in vec2 ma2;
+#define strength1 ma1.y
+#define strength2 ma2.y
 /* Position contains thickness in 4th component. */
 in vec4 pos;  /* Prev adj vert */
 in vec4 pos1; /* Current edge */
 in vec4 pos2; /* Current edge */
 in vec4 pos3; /* Next adj vert */
-
-in vec3 uv1;
-in vec3 uv2;
+/* xy is UV for fills, z is U of stroke, w is cosine of UV angle with sign of sine.  */
+in vec4 uv1;
+in vec4 uv2;
 
 in vec4 col1;
 in vec4 col2;
@@ -72,7 +74,7 @@ vec2 safe_normalize(vec2 v)
 void stroke_vertex()
 {
   /* Enpoints, we discard the vertices. */
-  if (ma1 == -1 || ma2 == -1) {
+  if (ma1.x == -1.0 || ma2.x == -1.0) {
     discard_vert();
     return;
   }
@@ -126,19 +128,24 @@ void stroke_vertex()
     thickness *= thicknessWorldScale * ProjectionMatrix[1][1] * sizeViewport.y;
   }
   /* Multiply scalars first. */
-  y *= thickness;
+  thickness *= y;
 
-  gl_Position.xy += miter * sizeViewportInv.xy * y;
+  gl_Position.xy += miter * sizeViewportInv.xy * thickness;
 
   vec4 vert_col = (x == 0.0) ? col1 : col2;
-  float vert_strength = (x == 0.0) ? uv1.z : uv2.z;
-  vec4 stroke_col = materials[ma1].stroke_color;
+  float vert_strength = (x == 0.0) ? strength1 : strength2;
+
+  int m = int(ma1.x);
+
+  vec4 stroke_col = materials[m].stroke_color;
   finalColor.rgb = mix(stroke_col.rgb, vert_col.rgb, vert_col.a);
   finalColor.a = clamp(stroke_col.a * vert_strength, 0.0, 1.0);
-  // finalColor *= vert_col;
   finalMixColor = vec4(0.0);
-  matFlag = materials[ma1].flag & ~GP_FILL_FLAGS;
-  finalUvs = (x == 0.0) ? uv1.xy : uv2.xy;
+
+  matFlag = materials[m].flag & ~GP_FILL_FLAGS;
+
+  finalUvs.x = (x == 0.0) ? uv1.z : uv2.z;
+  finalUvs.y = y * 0.5 + 0.5;
 }
 
 void dots_vertex()
@@ -154,13 +161,14 @@ void fill_vertex()
   gl_Position = point_world_to_ndc(wpos);
   gl_Position.z += 1e-2;
 
-  finalColor = materials[ma1].fill_color;
-  finalMixColor = materials[ma1].fill_mix_color;
-  matFlag = materials[ma1].flag & GP_FILL_FLAGS;
+  int m = int(ma1.x);
+
+  finalColor = materials[m].fill_color;
+  finalMixColor = materials[m].fill_mix_color;
+  matFlag = materials[m].flag & GP_FILL_FLAGS;
 
-  vec2 loc = materials[ma1].fill_uv_offset.xy;
-  mat2x2 rot_scale = mat2x2(materials[ma1].fill_uv_rot_scale.xy,
-                            materials[ma1].fill_uv_rot_scale.zw);
+  vec2 loc = materials[m].fill_uv_offset.xy;
+  mat2x2 rot_scale = mat2x2(materials[m].fill_uv_rot_scale.xy, materials[m].fill_uv_rot_scale.zw);
   finalUvs = rot_scale * uv1.xy + loc;
 }