[gtk/glyphy2: 32/32] wip: Use glyphy for line drawing

[Matthias Clasen <matthiasc src gnome org>]

commit 72e498e2386cb09492bd81d6c06f0cf0a434ce59
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Apr 6 17:10:53 2022 -0400

    wip: Use glyphy for line drawing
    
    This doesn't quite work right yet - our quads are very
    assymmetrical, which causes antialiasing mishaps.

 gsk/gl/gskglglyphylibrary.c        |  33 ++++----
 gsk/gl/gskglglyphylibraryprivate.h |   1 +
 gsk/gl/gskglrenderjob.c            | 160 ++++++++++++++++++++++++-------------
 tests/simple.c                     |  12 +--
 4 files changed, 126 insertions(+), 80 deletions(-)
---
diff --git a/gsk/gl/gskglglyphylibrary.c b/gsk/gl/gskglglyphylibrary.c
index 5d9277f44f..c32e723fab 100644
--- a/gsk/gl/gskglglyphylibrary.c
+++ b/gsk/gl/gskglglyphylibrary.c
@@ -346,6 +346,7 @@ encode_path (GskGLGlyphyLibrary *self,
   double enlighten_max = (double) upem * ENLIGHTEN_MAX;
   double embolden_max = (double) upem * EMBOLDEN_MAX;
   double avg_fetch_achieved;
+  graphene_rect_t bounds;
 
   self->acc_endpoints->len = 0;
 
@@ -358,7 +359,10 @@ encode_path (GskGLGlyphyLibrary *self,
   gsk_path_foreach (path, GSK_PATH_FOREACH_ALLOW_CURVE, acc_callback, self->acc);
 
   if (!glyphy_arc_accumulator_successful (self->acc))
-    return FALSE;
+    {
+      g_print ("failed to accumulate\n");
+      return FALSE;
+    }
 
   g_assert (glyphy_arc_accumulator_get_error (self->acc) <= tolerance);
 
@@ -380,7 +384,10 @@ encode_path (GskGLGlyphyLibrary *self,
                                      nominal_width,
                                      nominal_height,
                                      extents))
-    return FALSE;
+    {
+      g_print ("failed to encode\n");
+      return FALSE;
+    }
 
   glyphy_extents_scale (extents, 1./upem, 1./upem);
 
@@ -538,7 +545,7 @@ gsk_gl_glyphy_library_add (GskGLGlyphyLibrary      *self,
   return TRUE;
 }
 
-static glyphy_rgba_t buffer[128];
+static glyphy_rgba_t buffer[1024];
 static guint output_len = 0;
 static guint nominal_w;
 static guint nominal_h;
@@ -566,7 +573,7 @@ gsk_gl_glyphy_library_init_atlas (GskGLTextureLibrary *library,
       GskPath *path;
 
       builder = gsk_path_builder_new ();
-      gsk_path_builder_add_rect (builder, &GRAPHENE_RECT_INIT (0, 0, 1, 1));
+      gsk_path_builder_add_rect (builder, &GRAPHENE_RECT_INIT (0, 0, 1000, 1000));
       path = gsk_path_builder_free_to_path (builder);
 
       if (!encode_path (self, path, 1000, TOLERANCE,
@@ -588,15 +595,13 @@ gsk_gl_glyphy_library_init_atlas (GskGLTextureLibrary *library,
   glBindTexture (GL_TEXTURE_2D, atlas->texture_id);
   upload_buffer (0, 0, width, height, buffer, output_len);
 
-#if 0
-  value->extents.min_x = extents.min_x;
-  value->extents.min_y = extents.min_y;
-  value->extents.max_x = extents.max_x;
-  value->extents.max_y = extents.max_y;
-  value->nominal_w = nominal_w;
-  value->nominal_h = nominal_h;
-  value->atlas_x = 0;
-  value->atlas_y = 0;
-#endif
+  self->value0.extents.min_x = extents.min_x;
+  self->value0.extents.min_y = extents.min_y;
+  self->value0.extents.max_x = extents.max_x;
+  self->value0.extents.max_y = extents.max_y;
+  self->value0.nominal_w = nominal_w;
+  self->value0.nominal_h = nominal_h;
+  self->value0.atlas_x = 0;
+  self->value0.atlas_y = 0;
 }
 
diff --git a/gsk/gl/gskglglyphylibraryprivate.h b/gsk/gl/gskglglyphylibraryprivate.h
index fece808bcd..1dbb859842 100644
--- a/gsk/gl/gskglglyphylibraryprivate.h
+++ b/gsk/gl/gskglglyphylibraryprivate.h
@@ -99,6 +99,7 @@ struct _GskGLGlyphyLibrary
     GskGLGlyphyKey key;
     const GskGLGlyphyValue *value;
   } front[256];
+  GskGLGlyphyValue value0;
 };
 
 GskGLGlyphyLibrary *gsk_gl_glyphy_library_new (GskGLDriver             *driver);
diff --git a/gsk/gl/gskglrenderjob.c b/gsk/gl/gskglrenderjob.c
index b1f58b0e89..78cec00598 100644
--- a/gsk/gl/gskglrenderjob.c
+++ b/gsk/gl/gskglrenderjob.c
@@ -1420,6 +1420,61 @@ blur_node (GskGLRenderJob       *job,
 
 #define ATLAS_SIZE 512
 
+typedef struct
+{
+  float x;
+  float y;
+  float g16hi;
+  float g16lo;
+} EncodedGlyph;
+
+static inline unsigned int
+glyph_encode (guint atlas_x ,  /* 7 bits */
+              guint atlas_y,   /* 7 bits */
+              guint corner_x,  /* 1 bit */
+              guint corner_y,  /* 1 bit */
+              guint nominal_w, /* 6 bits */
+              guint nominal_h) /* 6 bits */
+{
+  guint x, y;
+
+  g_assert (0 == (atlas_x & ~0x7F));
+  g_assert (0 == (atlas_y & ~0x7F));
+  g_assert (0 == (corner_x & ~1));
+  g_assert (0 == (corner_y & ~1));
+  g_assert (0 == (nominal_w & ~0x3F));
+  g_assert (0 == (nominal_h & ~0x3F));
+
+  x = (((atlas_x << 6) | nominal_w) << 1) | corner_x;
+  y = (((atlas_y << 6) | nominal_h) << 1) | corner_y;
+
+  return (x << 16) | y;
+}
+
+static inline void
+encoded_glyph_init (EncodedGlyph           *eg,
+                    float                   x,
+                    float                   y,
+                    guint                   corner_x,
+                    guint                   corner_y,
+                    const GskGLGlyphyValue *gi)
+{
+  guint encoded = glyph_encode (gi->atlas_x, gi->atlas_y, corner_x, corner_y, gi->nominal_w, gi->nominal_h);
+
+  eg->x = x;
+  eg->y = y;
+  eg->g16hi = encoded >> 16;
+  eg->g16lo = encoded & 0xFFFF;
+}
+
+static inline void
+add_encoded_glyph (GskGLDrawVertex    *vertices,
+                   const EncodedGlyph *eg,
+                   const guint16       c[4])
+{
+  *vertices = (GskGLDrawVertex) { .position = { eg->x, eg->y}, .uv = { eg->g16hi, eg->g16lo}, .color = { 
c[0], c[1], c[2], c[3] } };
+}
+
 static inline void
 gsk_gl_render_job_visit_color_node (GskGLRenderJob      *job,
                                     const GskRenderNode *node)
@@ -1427,7 +1482,9 @@ gsk_gl_render_job_visit_color_node (GskGLRenderJob      *job,
   const GdkRGBA *rgba;
   guint16 color[4];
   GskGLProgram *program;
+  GskGLProgram *program1;
   GskGLCommandBatch *batch;
+  GskGLGlyphyLibrary *library;
 
   rgba = gsk_color_node_get_color (node);
   if (RGBA_IS_CLEAR (rgba))
@@ -1439,13 +1496,57 @@ gsk_gl_render_job_visit_color_node (GskGLRenderJob      *job,
    * rendering a solid color.
    */
   program = CHOOSE_PROGRAM (job, coloring);
+  program1 = CHOOSE_PROGRAM (job, glyphy);
   batch = gsk_gl_command_queue_get_batch (job->command_queue);
+  library = job->driver->glyphy_library;
 
   /* Limit the size, or we end up with a coordinate overflow somwhere. */
-  if (node->bounds.size.width < 300 &&
+  if (0 && node->bounds.size.width < 300 &&
       node->bounds.size.height < 300 &&
       batch->any.kind == GSK_GL_COMMAND_KIND_DRAW &&
-      batch->any.program == program->id)
+      batch->any.program == program1->id)
+    {
+      EncodedGlyph encoded[4];
+      GskGLDrawVertex *vertices;
+      graphene_point_t min, max;
+      graphene_rect_get_top_left (&node->bounds, &min);
+      graphene_rect_get_bottom_right (&node->bounds, &max);
+
+#define ENCODE_CORNER(_cx, _cy) \
+  G_STMT_START { \
+    encoded_glyph_init (&encoded[_cx * 2 + _cy], \
+                                 job->offset_x + (_cx ? max.x : min.x), \
+                                 job->offset_y + (_cy ? max.y : min.y), \
+                                 _cx, _cy, &library->value0); \
+  } G_STMT_END
+      ENCODE_CORNER (0, 0);
+      ENCODE_CORNER (0, 1);
+      ENCODE_CORNER (1, 0);
+      ENCODE_CORNER (1, 1);
+#undef ENCODE_CORNER
+
+      gsk_gl_render_job_begin_draw (job, program1);
+
+      gsk_gl_program_set_uniform1f (job->current_program,
+                                    UNIFORM_GLYPHY_BOLDNESS, 0,
+                                    0.0);
+
+      vertices = gsk_gl_command_queue_add_vertices (job->command_queue);
+
+      add_encoded_glyph (vertices++, &encoded[0], color);
+      add_encoded_glyph (vertices++, &encoded[1], color);
+      add_encoded_glyph (vertices++, &encoded[2], color);
+
+      add_encoded_glyph (vertices++, &encoded[1], color);
+      add_encoded_glyph (vertices++, &encoded[2], color);
+      add_encoded_glyph (vertices++, &encoded[3], color);
+
+      gsk_gl_render_job_end_draw (job);
+    }
+  else if (node->bounds.size.width < 300 &&
+           node->bounds.size.height < 300 &&
+           batch->any.kind == GSK_GL_COMMAND_KIND_DRAW &&
+           batch->any.program == program->id)
     {
       GskGLRenderOffscreen offscreen = {0};
 
@@ -3069,61 +3170,6 @@ gsk_gl_render_job_visit_text_node_legacy (GskGLRenderJob      *job,
   gsk_gl_render_job_end_draw (job);
 }
 
-typedef struct
-{
-  float x;
-  float y;
-  float g16hi;
-  float g16lo;
-} EncodedGlyph;
-
-static inline unsigned int
-glyph_encode (guint atlas_x ,  /* 7 bits */
-              guint atlas_y,   /* 7 bits */
-              guint corner_x,  /* 1 bit */
-              guint corner_y,  /* 1 bit */
-              guint nominal_w, /* 6 bits */
-              guint nominal_h) /* 6 bits */
-{
-  guint x, y;
-
-  g_assert (0 == (atlas_x & ~0x7F));
-  g_assert (0 == (atlas_y & ~0x7F));
-  g_assert (0 == (corner_x & ~1));
-  g_assert (0 == (corner_y & ~1));
-  g_assert (0 == (nominal_w & ~0x3F));
-  g_assert (0 == (nominal_h & ~0x3F));
-
-  x = (((atlas_x << 6) | nominal_w) << 1) | corner_x;
-  y = (((atlas_y << 6) | nominal_h) << 1) | corner_y;
-
-  return (x << 16) | y;
-}
-
-static inline void
-encoded_glyph_init (EncodedGlyph           *eg,
-                    float                   x,
-                    float                   y,
-                    guint                   corner_x,
-                    guint                   corner_y,
-                    const GskGLGlyphyValue *gi)
-{
-  guint encoded = glyph_encode (gi->atlas_x, gi->atlas_y, corner_x, corner_y, gi->nominal_w, gi->nominal_h);
-
-  eg->x = x;
-  eg->y = y;
-  eg->g16hi = encoded >> 16;
-  eg->g16lo = encoded & 0xFFFF;
-}
-
-static inline void
-add_encoded_glyph (GskGLDrawVertex    *vertices,
-                   const EncodedGlyph *eg,
-                   const guint16       c[4])
-{
-  *vertices = (GskGLDrawVertex) { .position = { eg->x, eg->y}, .uv = { eg->g16hi, eg->g16lo}, .color = { 
c[0], c[1], c[2], c[3] } };
-}
-
 static void
 get_synthetic_font_params (PangoFont   *font,
                            gboolean    *embolden,
diff --git a/tests/simple.c b/tests/simple.c
index 062afdc9fa..1434334415 100644
--- a/tests/simple.c
+++ b/tests/simple.c
@@ -45,17 +45,11 @@ main (int argc, char *argv[])
   gtk_init ();
 
   window = gtk_window_new ();
-  gtk_window_set_title (GTK_WINDOW (window), "hello world");
-  gtk_window_set_resizable (GTK_WINDOW (window), FALSE);
+  gtk_window_set_title (GTK_WINDOW (window), "");
   g_signal_connect (window, "destroy", G_CALLBACK (quit_cb), &done);
 
-  button = gtk_button_new ();
-  gtk_button_set_label (GTK_BUTTON (button), "hello world");
-  gtk_widget_set_margin_top (button, 10);
-  gtk_widget_set_margin_bottom (button, 10);
-  gtk_widget_set_margin_start (button, 10);
-  gtk_widget_set_margin_end (button, 10);
-  g_signal_connect (button, "clicked", G_CALLBACK (hello), NULL);
+  button = gtk_label_new ("");
+  gtk_label_set_markup (GTK_LABEL (button), "<s>XYZ</s>");
 
   gtk_window_set_child (GTK_WINDOW (window), button);