[client] egl: replace monolithic EGLTexture with modular version

The way things were handled in EGLTexture is not only very hard to
follow, but broken. This change set breaks up EGLTexture into a modular
design making it easier to implement the various versions.

Note that DMABUF is currently broken and needs to be re-implemented.

client/renderers/EGL/texture_util.c

@@ -0,0 +1,166 @@
+/**
+ * Looking Glass
+ * Copyright (C) 2017-2021 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "texture_util.h"
+
+#include <EGL/egl.h>
+#include <GLES3/gl3.h>
+#include <GLES2/gl2ext.h>
+
+#include "egldebug.h"
+
+/**
+ * the following comes from drm_fourcc.h and is included here to avoid the
+ * external dependency for the few simple defines we need
+ */
+#define fourcc_code(a, b, c, d) ((uint32_t)(a) | ((uint32_t)(b) << 8) | \
+         ((uint32_t)(c) << 16) | ((uint32_t)(d) << 24))
+#define DRM_FORMAT_ARGB8888      fourcc_code('A', 'R', '2', '4')
+#define DRM_FORMAT_ABGR8888      fourcc_code('A', 'B', '2', '4')
+#define DRM_FORMAT_BGRA1010102   fourcc_code('B', 'A', '3', '0')
+#define DRM_FORMAT_ABGR16161616F fourcc_code('A', 'B', '4', 'H')
+
+bool eglTexUtilGetFormat(const EGL_TexSetup * setup, EGL_TexFormat * fmt)
+{
+  switch(setup->pixFmt)
+  {
+    case EGL_PF_BGRA:
+      fmt->bpp        = 4;
+      fmt->format     = GL_BGRA_EXT;
+      fmt->intFormat  = GL_BGRA_EXT;
+      fmt->dataType   = GL_UNSIGNED_BYTE;
+      fmt->fourcc     = DRM_FORMAT_ARGB8888;
+      break;
+
+    case EGL_PF_RGBA:
+      fmt->bpp        = 4;
+      fmt->format     = GL_RGBA;
+      fmt->intFormat  = GL_RGBA;
+      fmt->dataType   = GL_UNSIGNED_BYTE;
+      fmt->fourcc     = DRM_FORMAT_ABGR8888;
+      break;
+
+    case EGL_PF_RGBA10:
+      fmt->bpp        = 4;
+      fmt->format     = GL_RGBA;
+      fmt->intFormat  = GL_RGB10_A2;
+      fmt->dataType   = GL_UNSIGNED_INT_2_10_10_10_REV;
+      fmt->fourcc     = DRM_FORMAT_BGRA1010102;
+      break;
+
+    case EGL_PF_RGBA16F:
+      fmt->bpp        = 8;
+      fmt->format     = GL_RGBA;
+      fmt->intFormat  = GL_RGBA16F;
+      fmt->dataType   = GL_HALF_FLOAT;
+      fmt->fourcc     = DRM_FORMAT_ABGR16161616F;
+      break;
+
+    default:
+      DEBUG_ERROR("Unsupported pixel format");
+      return false;
+  }
+
+  fmt->width      = setup->width;
+  fmt->height     = setup->height;
+  fmt->stride     = setup->stride;
+  fmt->pitch      = setup->stride / fmt->bpp;
+  fmt->bufferSize = setup->height * setup->stride;
+
+  return true;
+}
+
+bool eglTexUtilGenBuffers(const EGL_TexFormat * fmt, EGL_TexBuffer * buffers,
+    int count)
+{
+  for(int i = 0; i < count; ++i)
+  {
+    EGL_TexBuffer *buffer = &buffers[i];
+
+    buffer->size = fmt->bufferSize;
+    glGenBuffers(1, &buffer->pbo);
+    glBindBuffer(GL_PIXEL_UNPACK_BUFFER, buffer->pbo);
+    glBufferStorageEXT(
+      GL_PIXEL_UNPACK_BUFFER,
+      fmt->bufferSize,
+      NULL,
+      GL_MAP_WRITE_BIT          |
+      GL_MAP_PERSISTENT_BIT_EXT |
+      GL_MAP_COHERENT_BIT_EXT
+    );
+
+    if (!eglTexUtilMapBuffer(buffer))
+      return false;
+  }
+
+  return true;
+}
+
+void eglTexUtilFreeBuffers(EGL_TexBuffer * buffers, int count)
+{
+  for(int i = 0; i < count; ++i)
+  {
+    EGL_TexBuffer *buffer = &buffers[i];
+
+    if (!buffer->pbo)
+      continue;
+
+    eglTexUtilUnmapBuffer(buffer);
+    glDeleteBuffers(1, &buffer->pbo);
+    if (buffer->sync)
+    {
+      glDeleteSync(buffer->sync);
+      buffer->sync = 0;
+    }
+
+    buffer->pbo = 0;
+  }
+}
+
+bool eglTexUtilMapBuffer(EGL_TexBuffer * buffer)
+{
+  glBindBuffer(GL_PIXEL_UNPACK_BUFFER, buffer->pbo);
+  buffer->map = glMapBufferRange(
+      GL_PIXEL_UNPACK_BUFFER,
+      0,
+      buffer->size,
+      GL_MAP_WRITE_BIT             |
+      GL_MAP_UNSYNCHRONIZED_BIT    |
+      GL_MAP_INVALIDATE_BUFFER_BIT |
+      GL_MAP_PERSISTENT_BIT_EXT    |
+      GL_MAP_COHERENT_BIT_EXT);
+
+  if (!buffer->map)
+    DEBUG_GL_ERROR("glMapBufferRange failed of %lu bytes", buffer->size);
+
+  glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
+  return buffer->map;
+}
+
+void eglTexUtilUnmapBuffer(EGL_TexBuffer * buffer)
+{
+  if (!buffer->map)
+    return;
+
+  glBindBuffer(GL_PIXEL_UNPACK_BUFFER, buffer->pbo);
+  glUnmapBuffer(GL_PIXEL_UNPACK_BUFFER);
+  glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
+  buffer->map = NULL;
+}