wip! native: release dumb fb after flip for EGLStreams

fixme probably need to recreate the dumb fb any time doing
an explicit modeset

cogl/cogl/cogl-gpu-info-private.h

@@ -74,12 +74,7 @@ typedef enum
 
 typedef enum
 {
-  /* If this bug is present then it is faster to read pixels into a
+  COGL_GPU_INFO_DRIVER_STUB
-   * PBO and then memcpy out of the PBO into system memory rather than
-   * directly read into system memory.
-   * https://bugs.freedesktop.org/show_bug.cgi?id=46631
-   */
-  COGL_GPU_INFO_DRIVER_BUG_MESA_46631_SLOW_READ_PIXELS = 1 << 0
 } CoglGpuInfoDriverBug;
 
 typedef struct _CoglGpuInfoVersion CoglGpuInfoVersion;

cogl/cogl/cogl-gpu-info.c

@@ -568,13 +568,5 @@ probed:
              gpu->architecture_name);
 
   /* Determine the driver bugs */
-
+  gpu->driver_bugs = 0;
-  /* In Mesa the glReadPixels implementation is really slow
-     when using the Intel driver. The Intel
-     driver has a fast blit path when reading into a PBO. Reading into
-     a temporary PBO and then memcpying back out to the application's
-     memory is faster than a regular glReadPixels in this case */
-  if (gpu->vendor == COGL_GPU_INFO_VENDOR_INTEL &&
-      gpu->driver_package == COGL_GPU_INFO_DRIVER_PACKAGE_MESA)
-    gpu->driver_bugs |= COGL_GPU_INFO_DRIVER_BUG_MESA_46631_SLOW_READ_PIXELS;
 }

cogl/cogl/driver/gl/cogl-framebuffer-gl.c

@@ -4,6 +4,7 @@
  * A Low Level GPU Graphics and Utilities API
  *
  * Copyright (C) 2007,2008,2009,2012 Intel Corporation.
+ * Copyright (C) 2018 DisplayLink (UK) Ltd.
  *
  * Permission is hereby granted, free of charge, to any person
  * obtaining a copy of this software and associated documentation
@@ -1240,96 +1241,6 @@ _cogl_framebuffer_gl_draw_indexed_attributes (CoglFramebuffer *framebuffer,
   _cogl_buffer_gl_unbind (buffer);
 }
 
-static CoglBool
-mesa_46631_slow_read_pixels_workaround (CoglFramebuffer *framebuffer,
-                                        int x,
-                                        int y,
-                                        CoglReadPixelsFlags source,
-                                        CoglBitmap *bitmap,
-                                        CoglError **error)
-{
-  CoglContext *ctx;
-  CoglPixelFormat format;
-  CoglBitmap *pbo;
-  int width;
-  int height;
-  CoglBool res;
-  uint8_t *dst;
-  const uint8_t *src;
-
-  ctx = cogl_framebuffer_get_context (framebuffer);
-
-  width = cogl_bitmap_get_width (bitmap);
-  height = cogl_bitmap_get_height (bitmap);
-  format = cogl_bitmap_get_format (bitmap);
-
-  pbo = cogl_bitmap_new_with_size (ctx, width, height, format);
-
-  /* Read into the pbo. We need to disable the flipping because the
-     blit fast path in the driver does not work with
-     GL_PACK_INVERT_MESA is set */
-  res = _cogl_framebuffer_read_pixels_into_bitmap (framebuffer,
-                                                   x, y,
-                                                   source |
-                                                   COGL_READ_PIXELS_NO_FLIP,
-                                                   pbo,
-                                                   error);
-  if (!res)
-    {
-      cogl_object_unref (pbo);
-      return FALSE;
-    }
-
-  /* Copy the pixels back into application's buffer */
-  dst = _cogl_bitmap_map (bitmap,
-                          COGL_BUFFER_ACCESS_WRITE,
-                          COGL_BUFFER_MAP_HINT_DISCARD,
-                          error);
-  if (!dst)
-    {
-      cogl_object_unref (pbo);
-      return FALSE;
-    }
-
-  src = _cogl_bitmap_map (pbo,
-                          COGL_BUFFER_ACCESS_READ,
-                          0, /* hints */
-                          error);
-  if (src)
-    {
-      int src_rowstride = cogl_bitmap_get_rowstride (pbo);
-      int dst_rowstride = cogl_bitmap_get_rowstride (bitmap);
-      int to_copy =
-        _cogl_pixel_format_get_bytes_per_pixel (format) * width;
-      int y;
-
-      /* If the framebuffer is onscreen we need to flip the
-         data while copying */
-      if (!cogl_is_offscreen (framebuffer))
-        {
-          src += src_rowstride * (height - 1);
-          src_rowstride = -src_rowstride;
-        }
-
-      for (y = 0; y < height; y++)
-        {
-          memcpy (dst, src, to_copy);
-          dst += dst_rowstride;
-          src += src_rowstride;
-        }
-
-      _cogl_bitmap_unmap (pbo);
-    }
-  else
-    res = FALSE;
-
-  _cogl_bitmap_unmap (bitmap);
-
-  cogl_object_unref (pbo);
-
-  return res;
-}
-
 CoglBool
 _cogl_framebuffer_gl_read_pixels_into_bitmap (CoglFramebuffer *framebuffer,
                                               int x,
@@ -1350,40 +1261,6 @@ _cogl_framebuffer_gl_read_pixels_into_bitmap (CoglFramebuffer *framebuffer,
   CoglBool pack_invert_set;
   int status = FALSE;
 
-  /* Workaround for cases where its faster to read into a temporary
-   * PBO. This is only worth doing if:
-   *
-   * • The GPU is an Intel GPU. In that case there is a known
-   *   fast-path when reading into a PBO that will use the blitter
-   *   instead of the Mesa fallback code. The driver bug will only be
-   *   set if this is the case.
-   * • We're not already reading into a PBO.
-   * • The target format is BGRA. The fast-path blit does not get hit
-   *   otherwise.
-   * • The size of the data is not trivially small. This isn't a
-   *   requirement to hit the fast-path blit but intuitively it feels
-   *   like if the amount of data is too small then the cost of
-   *   allocating a PBO will outweigh the cost of temporarily
-   *   converting the data to floats.
-   */
-  if ((ctx->gpu.driver_bugs &
-       COGL_GPU_INFO_DRIVER_BUG_MESA_46631_SLOW_READ_PIXELS) &&
-      (width > 8 || height > 8) &&
-      (format & ~COGL_PREMULT_BIT) == COGL_PIXEL_FORMAT_BGRA_8888 &&
-      cogl_bitmap_get_buffer (bitmap) == NULL)
-    {
-      CoglError *ignore_error = NULL;
-
-      if (mesa_46631_slow_read_pixels_workaround (framebuffer,
-                                                  x, y,
-                                                  source,
-                                                  bitmap,
-                                                  &ignore_error))
-        return TRUE;
-      else
-        cogl_error_free (ignore_error);
-    }
-
   _cogl_framebuffer_flush_state (framebuffer,
                                  framebuffer,
                                  COGL_FRAMEBUFFER_STATE_BIND);
@@ -1397,9 +1274,12 @@ _cogl_framebuffer_gl_read_pixels_into_bitmap (CoglFramebuffer *framebuffer,
   if (!cogl_is_offscreen (framebuffer))
     y = framebuffer_height - y - height;
 
+  /* Use target format ANY, because GL texture_swizzle extension cannot
+   * ever apply for glReadPixels.
+   */
   required_format = ctx->driver_vtable->pixel_format_to_gl_with_target (ctx,
-                                                                        framebuffer->internal_format,
                                                                         format,
+                                                                        COGL_PIXEL_FORMAT_ANY,
                                                                         &gl_intformat,
                                                                         &gl_format,
                                                                         &gl_type);

src/backends/native/meta-renderer-native-gles3.c

@@ -179,6 +179,97 @@ paint_egl_image (MetaGles3   *gles3,
                                     GL_NEAREST));
 }
 
+/* FIXME: all these declarations are just floating here
+ */
+struct __attribute__ ((__packed__)) position
+{
+  float x, y;
+};
+
+struct __attribute__ ((__packed__)) texture_coordinate
+{
+  float u, v;
+};
+
+struct __attribute__ ((__packed__)) vertex
+{
+  struct position position;
+  struct texture_coordinate texture_coordinate;
+};
+
+struct __attribute__ ((__packed__)) triangle
+{
+  unsigned int first_vertex;
+  unsigned int middle_vertex;
+  unsigned int last_vertex;
+};
+
+enum
+{
+  RIGHT_TOP_VERTEX = 0,
+  BOTTOM_RIGHT_VERTEX,
+  BOTTOM_LEFT_VERTEX,
+  TOP_LEFT_VERTEX
+};
+
+static const float view_left = -1.0f, view_right = 1.0f, view_top = 1.0f, view_bottom = -1.0f;
+static const float texture_left = 0.0f, texture_right = 1.0f, texture_top = 0.0f, texture_bottom = 1.0f;
+static GLuint vertex_array;
+static GLuint vertex_buffer;
+static GLuint triangle_buffer;
+
+struct vertex vertices[] = {
+  [RIGHT_TOP_VERTEX] = {{view_right, view_top},
+                        {texture_right, texture_top}},
+  [BOTTOM_RIGHT_VERTEX] = {{view_right, view_bottom},
+                           {texture_right, texture_bottom}},
+  [BOTTOM_LEFT_VERTEX] = {{view_left, view_bottom},
+                          {texture_left, texture_bottom}},
+  [TOP_LEFT_VERTEX] = {{view_left, view_top},
+                       {texture_left, texture_top}},
+};
+
+struct triangle triangles[] = {
+  {TOP_LEFT_VERTEX, BOTTOM_RIGHT_VERTEX, BOTTOM_LEFT_VERTEX},
+  {TOP_LEFT_VERTEX, RIGHT_TOP_VERTEX, BOTTOM_RIGHT_VERTEX},
+};
+
+gboolean
+meta_renderer_native_gles3_draw_pixels (MetaEgl        *egl,
+                                        MetaGles3      *gles3,
+                                        unsigned int    width,
+                                        unsigned int    height,
+                                        uint8_t        *pixels,
+                                        GError        **error)
+{
+  meta_gles3_clear_error (gles3);
+
+  GLBAS (gles3, glClearColor, (0.0,1.0,0.0,1.0));
+  GLBAS (gles3, glClear, (GL_COLOR_BUFFER_BIT));
+
+  GLBAS (gles3, glViewport, (0, 0, width, height));
+  GLBAS (gles3, glTexImage2D, (GL_TEXTURE_2D, 0, GL_RGBA,
+                               width, height, 0, GL_RGBA,
+                               GL_UNSIGNED_BYTE, pixels));
+
+  GLBAS (gles3, glBindBuffer, (GL_ARRAY_BUFFER, vertex_buffer));
+  GLBAS (gles3, glEnableVertexAttribArray, (0));
+  GLBAS (gles3, glVertexAttribPointer, (0,
+                                        sizeof (struct position) / sizeof (float), GL_FLOAT,
+                                        GL_FALSE,
+                                        sizeof (struct vertex), (void *) offsetof (struct vertex, position)));
+  GLBAS (gles3, glEnableVertexAttribArray, (1));
+  GLBAS (gles3, glVertexAttribPointer, (1,
+                                        sizeof (struct texture_coordinate) / sizeof (float), GL_FLOAT,
+                                        GL_FALSE,
+                                        sizeof (struct vertex), (void *) offsetof (struct vertex, texture_coordinate)));
+  GLBAS (gles3, glDrawElements, (GL_TRIANGLES,
+                                 G_N_ELEMENTS (triangles) * (sizeof (struct triangle) / sizeof (unsigned int)), GL_UNSIGNED_INT,
+                                 0));
+
+  return TRUE;
+}
+
 gboolean
 meta_renderer_native_gles3_blit_shared_bo (MetaEgl        *egl,
                                            MetaGles3      *gles3,
@@ -238,3 +329,126 @@ meta_renderer_native_gles3_blit_shared_bo (MetaEgl        *egl,
 
   return TRUE;
 }
+
+static void
+meta_renderer_native_gles3_load_basic_shaders (MetaEgl   *egl,
+                                               MetaGles3 *gles3)
+{
+  GLuint vertex_shader = 0, fragment_shader = 0, shader_program;
+  gboolean status = FALSE;
+  const char *vertex_shader_source =
+"#version 330 core\n"
+"layout (location = 0) in vec2 position;\n"
+"layout (location = 1) in vec2 input_texture_coords;\n"
+"out vec2 texture_coords;\n"
+"void main()\n"
+"{\n"
+"  gl_Position = vec4(position.x, position.y, 0.0f, 1.0f);\n"
+"  texture_coords = input_texture_coords;\n"
+"}\n";
+
+  const char *fragment_shader_source =
+"#version 330 core\n"
+"uniform sampler2D input_texture;\n"
+"in vec2 texture_coords;\n"
+"out vec4 output_color;\n"
+"void main()\n"
+"{\n"
+/* FIXME: cogl uses a framebuffer format of COGL_PIXEL_FORMAT_RGBA_8888_PRE
+ * by default which maps to DRM_FORMAT_ABGR8888 on little endian.  The
+ * destination format is DRM_FORMAT_XRGB8888, so the color channels are
+ * swapped.  The .bgra swizzle here swaps it back, but we should see if
+ * we can find a better fix (this probably breaks on big endian) */
+"  output_color = texture(input_texture, texture_coords).bgra;\n"
+"}\n";
+
+  vertex_shader = glCreateShader (GL_VERTEX_SHADER);
+  glShaderSource (vertex_shader, 1, &vertex_shader_source, NULL);
+  glCompileShader (vertex_shader);
+  glGetShaderiv (vertex_shader, GL_COMPILE_STATUS, &status);
+
+  if (!status)
+    {
+      char compile_log[1024] = "";
+      glGetShaderInfoLog (vertex_shader, sizeof (compile_log), NULL, compile_log);
+      g_warning ("vertex shader compilation failed:\n %s\n", compile_log);
+      goto out;
+    }
+
+  fragment_shader = glCreateShader (GL_FRAGMENT_SHADER);
+  glShaderSource (fragment_shader, 1, &fragment_shader_source, NULL);
+  glCompileShader (fragment_shader);
+  glGetShaderiv (fragment_shader, GL_COMPILE_STATUS, &status);
+
+  if (!status)
+    {
+      char compile_log[1024] = "";
+      glGetShaderInfoLog (fragment_shader, sizeof (compile_log), NULL, compile_log);
+      g_warning ("fragment shader compilation failed:\n %s\n", compile_log);
+      goto out;
+    }
+
+  shader_program = glCreateProgram ();
+  glAttachShader (shader_program, vertex_shader);
+  glAttachShader (shader_program, fragment_shader);
+  glLinkProgram (shader_program);
+
+  glGetProgramiv (shader_program, GL_LINK_STATUS, &status);
+
+  if (!status)
+    {
+      char link_log[1024] = "";
+
+      glGetProgramInfoLog (shader_program, sizeof (link_log), NULL, link_log);
+      g_warning ("shader link failed:\n %s\n", link_log);
+      goto out;
+    }
+
+  glUseProgram (shader_program);
+
+out:
+  if (vertex_shader)
+    glDeleteShader (vertex_shader);
+  if (fragment_shader)
+    glDeleteShader (fragment_shader);
+}
+
+gboolean
+meta_renderer_native_gles3_prepare_for_drawing (MetaEgl    *egl,
+                                                MetaGles3  *gles3,
+                                                GError    **error)
+{
+  GLuint texture;
+
+  meta_renderer_native_gles3_load_basic_shaders (egl, gles3);
+
+  meta_gles3_clear_error (gles3);
+
+  GLBAS (gles3, glGenVertexArrays, (1, &vertex_array));
+  GLBAS (gles3, glBindVertexArray, (vertex_array));
+
+  GLBAS (gles3, glGenBuffers, (1, &vertex_buffer));
+  GLBAS (gles3, glBindBuffer, (GL_ARRAY_BUFFER, vertex_buffer));
+  GLBAS (gles3, glBufferData, (GL_ARRAY_BUFFER, sizeof (vertices), vertices, GL_STREAM_DRAW));
+
+  GLBAS (gles3, glGenBuffers, (1, &triangle_buffer));
+  GLBAS (gles3, glBindBuffer, (GL_ELEMENT_ARRAY_BUFFER, triangle_buffer));
+  GLBAS (gles3, glBufferData, (GL_ELEMENT_ARRAY_BUFFER, sizeof (triangles), triangles, GL_STREAM_DRAW));
+
+  GLBAS (gles3, glActiveTexture, (GL_TEXTURE0));
+  GLBAS (gles3, glGenTextures, (1, &texture));
+  GLBAS (gles3, glBindTexture, (GL_TEXTURE_2D, texture));
+
+  GLBAS (gles3, glTexParameteri, (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,
+                                  GL_NEAREST));
+  GLBAS (gles3, glTexParameteri, (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
+                                  GL_NEAREST));
+  GLBAS (gles3, glTexParameteri, (GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,
+                                  GL_CLAMP_TO_EDGE));
+  GLBAS (gles3, glTexParameteri, (GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,
+                                  GL_CLAMP_TO_EDGE));
+  GLBAS (gles3, glTexParameteri, (GL_TEXTURE_2D, GL_TEXTURE_WRAP_R_OES,
+                                  GL_CLAMP_TO_EDGE));
+
+  return TRUE;
+}

src/backends/native/meta-renderer-native-gles3.h

@@ -37,4 +37,15 @@ gboolean meta_renderer_native_gles3_blit_shared_bo (MetaEgl       *egl,
                                                     struct gbm_bo *shared_bo,
                                                     GError       **error);
 
+gboolean meta_renderer_native_gles3_prepare_for_drawing (MetaEgl    *egl,
+                                                         MetaGles3  *gles3,
+                                                         GError    **error);
+
+gboolean meta_renderer_native_gles3_draw_pixels (MetaEgl        *egl,
+                                                 MetaGles3      *gles3,
+                                                 unsigned int    width,
+                                                 unsigned int    height,
+                                                 uint8_t        *pixels,
+                                                 GError        **error);
+
 #endif /* META_RENDERER_NATIVE_GLES3_H */