VrShell: implement insecure content warning display

chrome/browser/android/vr_shell/vr_shell_renderer.cc

Index: chrome/browser/android/vr_shell/vr_shell_renderer.cc
diff --git a/chrome/browser/android/vr_shell/vr_shell_renderer.cc b/chrome/browser/android/vr_shell/vr_shell_renderer.cc
index 33e87fc6059a4fcb0206815df610fbed170a001f..7ed269e64b7f8b2097418c91ed04695fc2c3699a 100644
--- a/chrome/browser/android/vr_shell/vr_shell_renderer.cc
+++ b/chrome/browser/android/vr_shell/vr_shell_renderer.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "chrome/browser/android/vr_shell/vr_shell_icons.h"
 #include "chrome/browser/android/vr_shell/vr_shell_renderer.h"
 
 #include "chrome/browser/android/vr_shell/vr_gl_util.h"
@@ -41,6 +42,14 @@ const float kWebVrVertices[32] = {
      1.f,  1.f, 1.f, 0.f };
 const int kWebVrVerticesSize = sizeof(float) * 32;
 
+const float kOverlayIconVertices[32] = {
+  //   x     y    u,   v
+    -1.f,  1.f, 0.f, 0.f,
+    -1.f, -1.f, 0.f, 1.f,
+     1.f, -1.f, 1.f, 1.f,
+     1.f,  1.f, 1.f, 0.f};
+const int kOverlayIconVerticesSize = sizeof(float) * 16;
+
 // Reticle constants
 static constexpr float kRingDiameter = 1.0f;
 static constexpr float kInnerHole = 0.0f;
@@ -174,6 +183,27 @@ const char* GetShaderSource(vr_shell::ShaderID shader) {
             lowp vec4 final_color = color * texture_color;
             gl_FragColor = vec4(final_color.xyz, final_color.w * total_fade);
           });
+    case vr_shell::ShaderID::OVERLAY_ICON_VERTEX_SHADER:
+      return SHADER(
+          uniform mat4 u_CombinedMatrix;
+          attribute vec2 a_Position;
+          attribute vec2 a_TexCoordinate;
+          uniform vec4 u_SrcRect;
+          varying vec2 v_TexCoordinate;
+
+          void main() {
+            v_TexCoordinate = u_SrcRect.xy + (a_TexCoordinate * u_SrcRect.zw);
+            gl_Position = u_CombinedMatrix * vec4(a_Position, 0.0, 1.0);
+          });
+    case vr_shell::ShaderID::OVERLAY_ICON_FRAGMENT_SHADER:
+      return SHADER(
+          precision highp float;
+          uniform sampler2D u_Texture;
+          varying vec2 v_TexCoordinate;
+
+          void main() {
+            gl_FragColor = texture2D(u_Texture, v_TexCoordinate);
+          });
     default:
       LOG(ERROR) << "Shader source requested for unknown shader";
       return "";
@@ -439,11 +469,130 @@ void LaserRenderer::Draw(const gvr::Mat4f& combined_matrix) {
 
 LaserRenderer::~LaserRenderer() = default;
 
+void MakeTexImage(const icon_rle_image_t& icon,
+                  GLuint texture_data_handles[],
+                  int icon_id) {
+  // Helper function to decode a bitmap from Gimp ".c file"
+  // run length encoded format and store it as a texture.
+  // TODO(klausw): remove the Gimp decoding bits once we
+  // can create the content from text.
+
+  int image_pixels = icon.width * icon.height;
+  int image_bytes = image_pixels * icon.bytes_per_pixel;
+
+  char* image_data = (char*)malloc(image_bytes);
+  if (!image_data) {
+    LOG(ERROR) << "Failed to allocate memory for image " << icon_id;
+    exit(1);
+  }
+  ICON_RUN_LENGTH_DECODE(image_data, icon.rle_pixel_data,
+                         image_pixels, icon.bytes_per_pixel);
+
+  glBindTexture(GL_TEXTURE_2D, texture_data_handles[icon_id]);
+
+  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, icon.width, icon.height,
+               0, GL_RGBA, GL_UNSIGNED_BYTE, image_data);
+
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+}
+
+OverlayIconRenderer::OverlayIconRenderer() {
+  bounds_ = { 0.0f, 0.0f, 1.0f, 1.0f };
+
+  std::string error;
+  GLuint vertex_shader_handle = CompileShader(
+      GL_VERTEX_SHADER, GetShaderSource(OVERLAY_ICON_VERTEX_SHADER), error);
+  CHECK(vertex_shader_handle) << error;
+
+  GLuint fragment_shader_handle = CompileShader(
+      GL_FRAGMENT_SHADER, GetShaderSource(OVERLAY_ICON_FRAGMENT_SHADER), error);
+  CHECK(fragment_shader_handle) << error;
+
+  program_handle_ = CreateAndLinkProgram(
+      vertex_shader_handle, fragment_shader_handle, error);
+  CHECK(program_handle_) << error;
+
+  // Once the program is linked the shader objects are no longer needed
+  glDeleteShader(vertex_shader_handle);
+  glDeleteShader(fragment_shader_handle);
+
+  combined_matrix_handle_ =
+      glGetUniformLocation(program_handle_, "u_CombinedMatrix");
+  tex_uniform_handle_ = glGetUniformLocation(program_handle_, "u_Texture");
+  src_rect_uniform_handle_ = glGetUniformLocation(program_handle_, "u_SrcRect");
+  position_handle_ = glGetAttribLocation(program_handle_, "a_Position");
+  texcoord_handle_ = glGetAttribLocation(program_handle_, "a_TexCoordinate");
+
+  // TODO(bajones): Figure out why this need to be restored.
+  GLint old_buffer;
+  glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &old_buffer);
+
+  glGenBuffersARB(1, &vertex_buffer_);
+  glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer_);
+  glBufferData(GL_ARRAY_BUFFER, kOverlayIconVerticesSize, kOverlayIconVertices,
+      GL_STATIC_DRAW);
+
+  glBindBuffer(GL_ARRAY_BUFFER, old_buffer);
+
+  glGenTextures(ICON_ID_MAX, texture_data_handles_);
+
+  MakeTexImage(icon_not_secure_small, texture_data_handles_,
+               ICON_INSECURE_PERMANENT);
+  MakeTexImage(icon_not_secure_verbose, texture_data_handles_,
+               ICON_INSECURE_TRANSIENT);
+}
+
+void OverlayIconRenderer::Draw(const gvr::Mat4f& combined_matrix,
+                               int icon_num) {
+  // TODO(bajones): Figure out why this need to be restored.
+  GLint old_buffer;
+  glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &old_buffer);
+
+  glUseProgram(program_handle_);
+
+  // Bind vertex attributes
+  glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer_);
+
+  glEnableVertexAttribArray(position_handle_);
+  glEnableVertexAttribArray(texcoord_handle_);
+
+  // Pass in model view project matrix.
+  glUniformMatrix4fv(combined_matrix_handle_, 1, false,
+                     MatrixToGLArray(combined_matrix).data());
+
+  glVertexAttribPointer(position_handle_, POSITION_ELEMENTS, GL_FLOAT, false,
+      VERTEX_STRIDE, VOID_OFFSET(POSITION_OFFSET));
+  glVertexAttribPointer(texcoord_handle_, TEXCOORD_ELEMENTS, GL_FLOAT, false,
+      VERTEX_STRIDE, VOID_OFFSET(TEXCOORD_OFFSET));
+
+  // Bind texture.
+  glActiveTexture(GL_TEXTURE0);
+  glBindTexture(GL_TEXTURE_2D, texture_data_handles_[icon_num]);
+  glUniform1i(tex_uniform_handle_, 0);
+
+  glEnable(GL_BLEND);
+  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+  glUniform4fv(src_rect_uniform_handle_, 1, (float*)(&bounds_));
+  glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
+
+  glDisableVertexAttribArray(position_handle_);
+  glDisableVertexAttribArray(texcoord_handle_);
+
+  glBindBuffer(GL_ARRAY_BUFFER, old_buffer);
+}
+
+OverlayIconRenderer::~OverlayIconRenderer() = default;
+
 VrShellRenderer::VrShellRenderer()
     : textured_quad_renderer_(new TexturedQuadRenderer),
       webvr_renderer_(new WebVrRenderer),
       reticle_renderer_(new ReticleRenderer),
-      laser_renderer_(new LaserRenderer) {}
+      laser_renderer_(new LaserRenderer),
+      overlay_icon_renderer_(new OverlayIconRenderer) {}
 
 VrShellRenderer::~VrShellRenderer() = default;