[gtk/wip/chergert/glproto] gskglrenderer: First class support of repeating-radial-gradient

[Christian Hergert <chergert src gnome org>]

commit 51ed811e4c63121586103f1fa31528672ac8f87b
Author: Fabio Lagalla <lagfabio amazon com>
Date:   Tue Jan 26 12:49:16 2021 +0100

    gskglrenderer: First class support of repeating-radial-gradient

 gsk/gl/gskglrenderer.c                  | 7 ++++++-
 gsk/gl/gskglrenderops.c                 | 2 ++
 gsk/gl/gskglrenderopsprivate.h          | 2 ++
 gsk/gl/opbuffer.h                       | 1 +
 gsk/resources/glsl/radial_gradient.glsl | 5 +++++
 5 files changed, 16 insertions(+), 1 deletion(-)
---
diff --git a/gsk/gl/gskglrenderer.c b/gsk/gl/gskglrenderer.c
index ecd1028a69..b18f8e9efc 100644
--- a/gsk/gl/gskglrenderer.c
+++ b/gsk/gl/gskglrenderer.c
@@ -1486,6 +1486,7 @@ render_radial_gradient_node (GskGLRenderer   *self,
       ops_set_radial_gradient (builder,
                                n_color_stops,
                                stops,
+                               gsk_render_node_get_node_type (node) == GSK_REPEATING_RADIAL_GRADIENT_NODE,
                                builder->dx + center->x,
                                builder->dy + center->y,
                                start, end,
@@ -3078,6 +3079,8 @@ apply_radial_gradient_op (const Program          *program,
 
   scale = 1.0f / (op->end - op->start);
   bias = -op->start * scale;
+
+  glUniform1i (program->radial_gradient.repeat_location, op->repeat);
   glUniform2f (program->radial_gradient.range_location, scale, bias);
   glUniform4f (program->radial_gradient.geometry_location,
                op->center[0], op->center[1],
@@ -3405,6 +3408,7 @@ gsk_gl_renderer_create_programs (GskGLRenderer  *self,
   /* radial gradient */
   INIT_PROGRAM_UNIFORM_LOCATION (radial_gradient, color_stops);
   INIT_PROGRAM_UNIFORM_LOCATION (radial_gradient, num_color_stops);
+  INIT_PROGRAM_UNIFORM_LOCATION (radial_gradient, repeat);
   INIT_PROGRAM_UNIFORM_LOCATION (radial_gradient, geometry);
   INIT_PROGRAM_UNIFORM_LOCATION (radial_gradient, range);
 
@@ -3763,6 +3767,8 @@ gsk_gl_renderer_add_render_ops (GskGLRenderer   *self,
     break;
 
     case GSK_RADIAL_GRADIENT_NODE:
+      /* Intentional fall-through */
+    case GSK_REPEATING_RADIAL_GRADIENT_NODE:
       render_radial_gradient_node (self, node, builder);
     break;
 
@@ -3829,7 +3835,6 @@ gsk_gl_renderer_add_render_ops (GskGLRenderer   *self,
       render_gl_shader_node (self, node, builder);
     break;
 
-    case GSK_REPEATING_RADIAL_GRADIENT_NODE:
     case GSK_CAIRO_NODE:
     default:
       {
diff --git a/gsk/gl/gskglrenderops.c b/gsk/gl/gskglrenderops.c
index ec14be1e13..ad9518b228 100644
--- a/gsk/gl/gskglrenderops.c
+++ b/gsk/gl/gskglrenderops.c
@@ -924,6 +924,7 @@ void
 ops_set_radial_gradient (RenderOpBuilder    *self,
                          guint               n_color_stops,
                          const GskColorStop *color_stops,
+                         bool                repeat,
                          float               center_x,
                          float               center_y,
                          float               start,
@@ -947,6 +948,7 @@ ops_set_radial_gradient (RenderOpBuilder    *self,
   op->radius[1] = vradius;
   op->start = start;
   op->end = end;
+  op->repeat = repeat;
 }
 
 void
diff --git a/gsk/gl/gskglrenderopsprivate.h b/gsk/gl/gskglrenderopsprivate.h
index ccc63ab074..d556009d06 100644
--- a/gsk/gl/gskglrenderopsprivate.h
+++ b/gsk/gl/gskglrenderopsprivate.h
@@ -126,6 +126,7 @@ struct _Program
       int color_stops_location;
       int geometry_location;
       int range_location;
+      int repeat_location;
     } radial_gradient;
     struct {
       int num_color_stops_location;
@@ -324,6 +325,7 @@ void              ops_set_linear_gradient (RenderOpBuilder     *self,
 void              ops_set_radial_gradient (RenderOpBuilder        *self,
                                            guint                   n_color_stops,
                                            const GskColorStop     *color_stops,
+                                           bool                    repeat,
                                            float                   center_x,
                                            float                   center_y,
                                            float                   start,
diff --git a/gsk/gl/opbuffer.h b/gsk/gl/opbuffer.h
index 4241214a37..a5c1af9189 100644
--- a/gsk/gl/opbuffer.h
+++ b/gsk/gl/opbuffer.h
@@ -157,6 +157,7 @@ typedef struct
   float end;
   float radius[2];
   float center[2];
+  bool repeat;
 } OpRadialGradient;
 
 typedef struct
diff --git a/gsk/resources/glsl/radial_gradient.glsl b/gsk/resources/glsl/radial_gradient.glsl
index 9834a69ba4..0ab3fdf07a 100644
--- a/gsk/resources/glsl/radial_gradient.glsl
+++ b/gsk/resources/glsl/radial_gradient.glsl
@@ -22,6 +22,7 @@ uniform int u_num_color_stops;
 uniform highp int u_num_color_stops;
 #endif
 
+uniform bool u_repeat;
 uniform vec2 u_range;
 uniform float u_color_stops[6 * 5];
 
@@ -44,6 +45,10 @@ void main() {
   // Reverse scale
   float offset = length(coord) * u_range.x + u_range.y;
 
+  if (u_repeat) {
+    offset = fract(offset);
+  }
+
   if (offset < get_offset(0)) {
     gskSetOutputColor(gsk_scaled_premultiply(get_color(0), u_alpha));
     return;