openpilot_comma/selfdrive/ui/paint.cc

#include "ui.hpp"

#include <assert.h>
#include <map>
#include <cmath>
#include <iostream>
#include "common/util.h"
#include "common/timing.h"
#include <algorithm>

#define NANOVG_GLES3_IMPLEMENTATION
#include "nanovg_gl.h"
#include "nanovg_gl_utils.h"

extern "C"{
#include "common/glutil.h"
}

#include "paint.hpp"
#include "sidebar.hpp"


// TODO: this is also hardcoded in common/transformations/camera.py
// TODO: choose based on frame input size
#ifdef QCOM2
const float y_offset = 150.0;
const float zoom = 1.1;
const mat3 intrinsic_matrix = (mat3){{
  2648.0, 0.0, 1928.0/2,
  0.0, 2648.0, 1208.0/2,
  0.0,   0.0,   1.0
}};
#else
const float y_offset = 0.0;
const float zoom = 2.35;
const mat3 intrinsic_matrix = (mat3){{
  910., 0., 1164.0/2,
  0., 910., 874.0/2,
  0.,   0.,   1.
}};
#endif

// Projects a point in car to space to the corresponding point in full frame
// image space.
bool car_space_to_full_frame(const UIState *s, float in_x, float in_y, float in_z, vertex_data *out, float margin) {
  const vec4 car_space_projective = (vec4){{in_x, in_y, in_z, 1.}};
  // We'll call the car space point p.
  // First project into normalized image coordinates with the extrinsics matrix.
  const vec4 Ep4 = matvecmul(s->scene.extrinsic_matrix, car_space_projective);

  // The last entry is zero because of how we store E (to use matvecmul).
  const vec3 Ep = {{Ep4.v[0], Ep4.v[1], Ep4.v[2]}};
  const vec3 KEp = matvecmul3(intrinsic_matrix, Ep);

  // Project.
  out->x = KEp.v[0] / KEp.v[2];
  out->y = KEp.v[1] / KEp.v[2];

  return out->x >= -margin && out->x <= s->fb_w + margin && out->y >= -margin && out->y <= s->fb_h + margin;
}


static void ui_draw_text(NVGcontext *vg, float x, float y, const char* string, float size, NVGcolor color, int font){
  nvgFontFaceId(vg, font);
  nvgFontSize(vg, size);
  nvgFillColor(vg, color);
  nvgText(vg, x, y, string, NULL);
}

static void draw_chevron(UIState *s, float x_in, float y_in, float sz,
                          NVGcolor fillColor, NVGcolor glowColor) {
  vertex_data out;
  if (!car_space_to_full_frame(s, x_in, y_in, 0.0, &out)) return;

  auto [x, y] = out;
  sz = std::clamp((sz * 30) / (x_in / 3 + 30), 15.0f, 30.0f);

  // glow
  float g_xo = sz/5;
  float g_yo = sz/10;
  nvgBeginPath(s->vg);
  nvgMoveTo(s->vg, x+(sz*1.35)+g_xo, y+sz+g_yo);
  nvgLineTo(s->vg, x, y-g_xo);
  nvgLineTo(s->vg, x-(sz*1.35)-g_xo, y+sz+g_yo);
  nvgClosePath(s->vg);
  nvgFillColor(s->vg, glowColor);
  nvgFill(s->vg);

  // chevron
  nvgBeginPath(s->vg);
  nvgMoveTo(s->vg, x+(sz*1.25), y+sz);
  nvgLineTo(s->vg, x, y);
  nvgLineTo(s->vg, x-(sz*1.25), y+sz);
  nvgClosePath(s->vg);
  nvgFillColor(s->vg, fillColor);
  nvgFill(s->vg);
}

static void ui_draw_circle_image(NVGcontext *vg, int x, int y, int size, int image, NVGcolor color, float img_alpha, int img_y = 0) {
  const int img_size = size * 1.5;
  nvgBeginPath(vg);
  nvgCircle(vg, x, y + (bdr_s * 1.5), size);
  nvgFillColor(vg, color);
  nvgFill(vg);
  const Rect rect = {x - (img_size / 2), img_y ? img_y : y - (size / 4), img_size, img_size};
  ui_draw_image(vg, rect, image, img_alpha);
}

static void ui_draw_circle_image(NVGcontext *vg, int x, int y, int size, int image, bool active) {
  float bg_alpha = active ? 0.3f : 0.1f;
  float img_alpha = active ? 1.0f : 0.15f;
  ui_draw_circle_image(vg, x, y, size, image, nvgRGBA(0, 0, 0, (255 * bg_alpha)), img_alpha);
}

static void draw_lead(UIState *s, const cereal::RadarState::LeadData::Reader &lead){
  // Draw lead car indicator
  float fillAlpha = 0;
  float speedBuff = 10.;
  float leadBuff = 40.;
  float d_rel = lead.getDRel();
  float v_rel = lead.getVRel();
  if (d_rel < leadBuff) {
    fillAlpha = 255*(1.0-(d_rel/leadBuff));
    if (v_rel < 0) {
      fillAlpha += 255*(-1*(v_rel/speedBuff));
    }
    fillAlpha = (int)(fmin(fillAlpha, 255));
  }
  draw_chevron(s, d_rel, lead.getYRel(), 25, nvgRGBA(201, 34, 49, fillAlpha), COLOR_YELLOW);
}

static void ui_draw_line(UIState *s, const vertex_data *v, const int cnt, NVGcolor *color, NVGpaint *paint) {
  if (cnt == 0) return;

  nvgBeginPath(s->vg);
  nvgMoveTo(s->vg, v[0].x, v[0].y);
  for (int i = 1; i < cnt; i++) {
    nvgLineTo(s->vg, v[i].x, v[i].y);
  }
  nvgClosePath(s->vg);
  if (color) {
    nvgFillColor(s->vg, *color);
  } else if (paint) {
    nvgFillPaint(s->vg, *paint);
  }
  nvgFill(s->vg);
}

static void draw_frame(UIState *s) {
  mat4 *out_mat;
  if (s->scene.frontview) {
    glBindVertexArray(s->frame_vao[1]);
    out_mat = &s->front_frame_mat;
  } else {
    glBindVertexArray(s->frame_vao[0]);
    out_mat = &s->rear_frame_mat;
  }
  glActiveTexture(GL_TEXTURE0);

  if (s->last_frame) {
    glBindTexture(GL_TEXTURE_2D, s->texture[s->last_frame->idx]->frame_tex);
#ifndef QCOM
    // this is handled in ion on QCOM
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, s->last_frame->width, s->last_frame->height,
                 0, GL_RGB, GL_UNSIGNED_BYTE, s->last_frame->addr);
#endif
  }

  glUseProgram(s->frame_program);
  glUniform1i(s->frame_texture_loc, 0);
  glUniformMatrix4fv(s->frame_transform_loc, 1, GL_TRUE, out_mat->v);

  assert(glGetError() == GL_NO_ERROR);
  glEnableVertexAttribArray(0);
  glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_BYTE, (const void*)0);
  glDisableVertexAttribArray(0);
  glBindVertexArray(0);
}

static void ui_draw_vision_lane_lines(UIState *s) {
  const UIScene &scene = s->scene;
  // paint lanelines
  for (int i = 0; i < std::size(scene.lane_line_vertices); i++) {
    NVGcolor color = nvgRGBAf(1.0, 1.0, 1.0, scene.lane_line_probs[i]);
    ui_draw_line(s, scene.lane_line_vertices[i].v, scene.lane_line_vertices[i].cnt, &color, nullptr);
  }

  // paint road edges
  for (int i = 0; i < std::size(scene.road_edge_vertices); i++) {
    NVGcolor color = nvgRGBAf(1.0, 0.0, 0.0, std::clamp<float>(1.0 - scene.road_edge_stds[i], 0.0, 1.0));
    ui_draw_line(s, scene.road_edge_vertices[i].v, scene.road_edge_vertices[i].cnt, &color, nullptr);
  }

  // paint path
  NVGpaint track_bg = nvgLinearGradient(s->vg, s->fb_w, s->fb_h, s->fb_w, s->fb_h * .4,
                                        COLOR_WHITE, COLOR_WHITE_ALPHA(0));
  ui_draw_line(s, scene.track_vertices.v, scene.track_vertices.cnt, nullptr, &track_bg);
}

// Draw all world space objects.
static void ui_draw_world(UIState *s) {
  const UIScene *scene = &s->scene;

  nvgSave(s->vg);

  // Don't draw on top of sidebar
  nvgScissor(s->vg, scene->viz_rect.x, scene->viz_rect.y, scene->viz_rect.w, scene->viz_rect.h);

  // Apply transformation such that video pixel coordinates match video
  // 1) Put (0, 0) in the middle of the video
  nvgTranslate(s->vg, s->video_rect.x + s->video_rect.w / 2, s->video_rect.y + s->video_rect.h / 2 + y_offset);

  // 2) Apply same scaling as video
  nvgScale(s->vg, zoom, zoom);

  // 3) Put (0, 0) in top left corner of video
  nvgTranslate(s->vg, -intrinsic_matrix.v[2], -intrinsic_matrix.v[5]);

  // Draw lane edges and vision/mpc tracks
  ui_draw_vision_lane_lines(s);

  // Draw lead indicators if openpilot is handling longitudinal
  if (s->longitudinal_control) {
    if (scene->lead_data[0].getStatus()) {
      draw_lead(s, scene->lead_data[0]);
    }
    if (scene->lead_data[1].getStatus() && (std::abs(scene->lead_data[0].getDRel() - scene->lead_data[1].getDRel()) > 3.0)) {
      draw_lead(s, scene->lead_data[1]);
    }
  }
  nvgRestore(s->vg);
}

static void ui_draw_vision_maxspeed(UIState *s) {
  float maxspeed = s->scene.controls_state.getVCruise();
  const bool is_cruise_set = maxspeed != 0 && maxspeed != SET_SPEED_NA;
  if (is_cruise_set && !s->is_metric) { maxspeed *= 0.6225; }

  auto [x, y, w, h] = std::tuple(s->scene.viz_rect.x + (bdr_s * 2), s->scene.viz_rect.y + (bdr_s * 1.5), 184, 202);

  ui_draw_rect(s->vg, x, y, w, h, COLOR_BLACK_ALPHA(100), 30);
  ui_draw_rect(s->vg, x, y, w, h, COLOR_WHITE_ALPHA(100), 20, 10);

  nvgTextAlign(s->vg, NVG_ALIGN_CENTER | NVG_ALIGN_BASELINE);
  ui_draw_text(s->vg, x + w / 2, 148, "MAX", 26 * 2.5, COLOR_WHITE_ALPHA(is_cruise_set ? 200 : 100), s->font_sans_regular);
  if (is_cruise_set) {
    const std::string maxspeed_str = std::to_string((int)std::nearbyint(maxspeed));
    ui_draw_text(s->vg, x + w / 2, 242, maxspeed_str.c_str(), 48 * 2.5, COLOR_WHITE, s->font_sans_bold);
  } else {
    ui_draw_text(s->vg, x + w / 2, 242, "N/A", 42 * 2.5, COLOR_WHITE_ALPHA(100), s->font_sans_semibold);
  }
}

static void ui_draw_vision_speed(UIState *s) {
  const float speed = std::max(0.0, s->scene.controls_state.getVEgo() * (s->is_metric ? 3.6 : 2.2369363));
  const std::string speed_str = std::to_string((int)std::nearbyint(speed));
  nvgTextAlign(s->vg, NVG_ALIGN_CENTER | NVG_ALIGN_BASELINE);
  ui_draw_text(s->vg, s->scene.viz_rect.centerX(), 240, speed_str.c_str(), 96 * 2.5, COLOR_WHITE, s->font_sans_bold);
  ui_draw_text(s->vg, s->scene.viz_rect.centerX(), 320, s->is_metric ? "km/h" : "mph", 36 * 2.5, COLOR_WHITE_ALPHA(200), s->font_sans_regular);
}

static void ui_draw_vision_event(UIState *s) {
  const int viz_event_w = 220;
  const int viz_event_x = s->scene.viz_rect.right() - (viz_event_w + bdr_s*2);
  const int viz_event_y = s->scene.viz_rect.y + (bdr_s*1.5);
  if (s->scene.controls_state.getDecelForModel() && s->scene.controls_state.getEnabled()) {
    // draw winding road sign
    const int img_turn_size = 160*1.5;
    const Rect rect = {viz_event_x - (img_turn_size / 4), viz_event_y + bdr_s - 25, img_turn_size, img_turn_size};
    ui_draw_image(s->vg, rect, s->img_turn, 1.0f);
  } else if (s->scene.controls_state.getEngageable()) {
    // draw steering wheel
    const int bg_wheel_size = 96;
    const int bg_wheel_x = viz_event_x + (viz_event_w-bg_wheel_size);
    const int bg_wheel_y = viz_event_y + (bg_wheel_size/2);
    const NVGcolor color = bg_colors[s->status];

    ui_draw_circle_image(s->vg, bg_wheel_x, bg_wheel_y, bg_wheel_size, s->img_wheel, color, 1.0f, bg_wheel_y - 25);
  }
}

static void ui_draw_vision_face(UIState *s) {
  const int face_size = 96;
  const int face_x = (s->scene.viz_rect.x + face_size + (bdr_s * 2));
  const int face_y = (s->scene.viz_rect.bottom() - footer_h + ((footer_h - face_size) / 2));
  ui_draw_circle_image(s->vg, face_x, face_y, face_size, s->img_face, s->scene.dmonitoring_state.getFaceDetected());
}

static void ui_draw_driver_view(UIState *s) {
  s->scene.sidebar_collapsed = true;
  const bool is_rhd = s->scene.is_rhd;
  const Rect &viz_rect = s->scene.viz_rect; 
  const int width = 3 * viz_rect.w / 4;
  const Rect rect = {viz_rect.centerX() - width / 2, viz_rect.y, width, viz_rect.h};  // x, y, w, h
  const Rect valid_rect = {is_rhd ? rect.right() - rect.h / 2 : rect.x, rect.y, rect.h / 2, rect.h};

  // blackout
  const int blackout_x = is_rhd ? rect.x : valid_rect.right();
  const int blackout_w = rect.w - valid_rect.w;
  NVGpaint gradient = nvgLinearGradient(s->vg, blackout_x, rect.y, blackout_x + blackout_w, rect.y,
                                        COLOR_BLACK_ALPHA(is_rhd ? 255 : 0), COLOR_BLACK_ALPHA(is_rhd ? 0 : 255));
  ui_draw_rect(s->vg, blackout_x, rect.y, blackout_w, rect.h, gradient);
  ui_draw_rect(s->vg, blackout_x, rect.y, blackout_w, rect.h, COLOR_BLACK_ALPHA(144));
  // border
  ui_draw_rect(s->vg, rect.x, rect.y, rect.w, rect.h, bg_colors[STATUS_OFFROAD], 0, 1);

  const bool face_detected = s->scene.dmonitoring_state.getFaceDetected();
  if (face_detected) {
    auto fxy_list = s->scene.driver_state.getFacePosition();
    float face_x = fxy_list[0];
    float face_y = fxy_list[1];
    float fbox_x = valid_rect.centerX() + (is_rhd ? face_x : -face_x) * valid_rect.w;
    float fbox_y = valid_rect.centerY() + face_y * valid_rect.h;

    float alpha = 0.2;
    if (face_x = std::abs(face_x), face_y = std::abs(face_y); face_x <= 0.35 && face_y <= 0.4)
      alpha = 0.8 - (face_x > face_y ? face_x : face_y) * 0.6 / 0.375;

    const float box_size = 0.6 * rect.h / 2;
    ui_draw_rect(s->vg, fbox_x - box_size / 2, fbox_y - box_size / 2, box_size, box_size, nvgRGBAf(1.0, 1.0, 1.0, alpha), 35, 10);
  }

  // draw face icon
  const int face_size = 85;
  const int icon_x = is_rhd ? rect.right() - face_size - bdr_s * 2 : rect.x + face_size + bdr_s * 2;
  const int icon_y = rect.bottom() - face_size - bdr_s * 2.5;
  ui_draw_circle_image(s->vg, icon_x, icon_y, face_size, s->img_face, face_detected);
}

static void ui_draw_vision_header(UIState *s) {
  const Rect &viz_rect = s->scene.viz_rect;
  NVGpaint gradient = nvgLinearGradient(s->vg, viz_rect.x,
                        viz_rect.y+(header_h-(header_h/2.5)),
                        viz_rect.x, viz_rect.y+header_h,
                        nvgRGBAf(0,0,0,0.45), nvgRGBAf(0,0,0,0));

  ui_draw_rect(s->vg, viz_rect.x, viz_rect.y, viz_rect.w, header_h, gradient);

  ui_draw_vision_maxspeed(s);
  ui_draw_vision_speed(s);
  ui_draw_vision_event(s);
}

static void ui_draw_vision_footer(UIState *s) {
  ui_draw_vision_face(s);
}

static float get_alert_alpha(float blink_rate) {
  return 0.375 * cos((millis_since_boot() / 1000) * 2 * M_PI * blink_rate) + 0.625;
}

static void ui_draw_vision_alert(UIState *s) {
  static std::map<cereal::ControlsState::AlertSize, const int> alert_size_map = {
      {cereal::ControlsState::AlertSize::SMALL, 241},
      {cereal::ControlsState::AlertSize::MID, 390},
      {cereal::ControlsState::AlertSize::FULL, s->fb_h}};
  const UIScene *scene = &s->scene;
  bool longAlert1 = scene->alert_text1.length() > 15;

  NVGcolor color = bg_colors[s->status];
  color.a *= get_alert_alpha(scene->alert_blinking_rate);
  int alr_s = alert_size_map[scene->alert_size];

  const int alr_x = scene->viz_rect.x - bdr_s;
  const int alr_w = scene->viz_rect.w + (bdr_s * 2);
  const int alr_h = alr_s + bdr_s;
  const int alr_y = s->fb_h - alr_h;

  ui_draw_rect(s->vg, alr_x, alr_y, alr_w, alr_h, color);

  NVGpaint gradient = nvgLinearGradient(s->vg, alr_x, alr_y, alr_x, alr_y+alr_h,
                                        nvgRGBAf(0.0,0.0,0.0,0.05), nvgRGBAf(0.0,0.0,0.0,0.35));
  ui_draw_rect(s->vg, alr_x, alr_y, alr_w, alr_h, gradient);

  nvgFillColor(s->vg, COLOR_WHITE);
  nvgTextAlign(s->vg, NVG_ALIGN_CENTER | NVG_ALIGN_BASELINE);

  if (scene->alert_size == cereal::ControlsState::AlertSize::SMALL) {
    ui_draw_text(s->vg, alr_x+alr_w/2, alr_y+alr_h/2+15, scene->alert_text1.c_str(), 40*2.5, COLOR_WHITE, s->font_sans_semibold);
  } else if (scene->alert_size == cereal::ControlsState::AlertSize::MID) {
    ui_draw_text(s->vg, alr_x+alr_w/2, alr_y+alr_h/2-45, scene->alert_text1.c_str(), 48*2.5, COLOR_WHITE, s->font_sans_bold);
    ui_draw_text(s->vg, alr_x+alr_w/2, alr_y+alr_h/2+75, scene->alert_text2.c_str(), 36*2.5, COLOR_WHITE, s->font_sans_regular);
  } else if (scene->alert_size == cereal::ControlsState::AlertSize::FULL) {
    nvgFontSize(s->vg, (longAlert1?72:96)*2.5);
    nvgFontFaceId(s->vg, s->font_sans_bold);
    nvgTextAlign(s->vg, NVG_ALIGN_CENTER | NVG_ALIGN_MIDDLE);
    nvgTextBox(s->vg, alr_x, alr_y+(longAlert1?360:420), alr_w-60, scene->alert_text1.c_str(), NULL);
    nvgFontSize(s->vg, 48*2.5);
    nvgFontFaceId(s->vg,  s->font_sans_regular);
    nvgTextAlign(s->vg, NVG_ALIGN_CENTER | NVG_ALIGN_BOTTOM);
    nvgTextBox(s->vg, alr_x, alr_h-(longAlert1?300:360), alr_w-60, scene->alert_text2.c_str(), NULL);
  }
}

static void ui_draw_vision_frame(UIState *s) {
  const UIScene *scene = &s->scene;
  const Rect &viz_rect = scene->viz_rect;

  // Draw video frames
  glEnable(GL_SCISSOR_TEST);
  glViewport(s->video_rect.x, s->video_rect.y, s->video_rect.w, s->video_rect.h);
  glScissor(viz_rect.x, viz_rect.y, viz_rect.w, viz_rect.h);
  draw_frame(s);
  glDisable(GL_SCISSOR_TEST);

  glViewport(0, 0, s->fb_w, s->fb_h);
}

static void ui_draw_vision(UIState *s) {
  const UIScene *scene = &s->scene;
  if (!scene->frontview) {
    // Draw augmented elements
    if (scene->world_objects_visible) {
      ui_draw_world(s);
    }
    // Set Speed, Current Speed, Status/Events
    ui_draw_vision_header(s);
    if (scene->alert_size == cereal::ControlsState::AlertSize::NONE) {
      ui_draw_vision_footer(s);
    }
  } else {
    ui_draw_driver_view(s);
  }
}

static void ui_draw_background(UIState *s) {
  const NVGcolor color = bg_colors[s->status];
  glClearColor(color.r, color.g, color.b, 1.0);
  glClear(GL_STENCIL_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
}

void ui_draw(UIState *s) {
  s->scene.viz_rect = Rect{bdr_s, bdr_s, s->fb_w - 2 * bdr_s, s->fb_h - 2 * bdr_s};
  if (!s->scene.sidebar_collapsed) {
    s->scene.viz_rect.x += sbr_w;
    s->scene.viz_rect.w -= sbr_w;
  }

  const bool draw_vision = s->started && s->status != STATUS_OFFROAD &&
    s->active_app == cereal::UiLayoutState::App::NONE && s->vipc_client->connected;

  // GL drawing functions
  ui_draw_background(s);
  if (draw_vision) {
    ui_draw_vision_frame(s);
  }
  glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  glViewport(0, 0, s->fb_w, s->fb_h);

  // NVG drawing functions - should be no GL inside NVG frame
  nvgBeginFrame(s->vg, s->fb_w, s->fb_h, 1.0f);
  ui_draw_sidebar(s);
  if (draw_vision) {
    ui_draw_vision(s);
  }

  if (draw_vision && s->scene.alert_size != cereal::ControlsState::AlertSize::NONE) {
    ui_draw_vision_alert(s);
  }
  nvgEndFrame(s->vg);
  glDisable(GL_BLEND);
}

void ui_draw_image(NVGcontext *vg, const Rect &r, int image, float alpha){
  nvgBeginPath(vg);
  NVGpaint imgPaint = nvgImagePattern(vg, r.x, r.y, r.w, r.h, 0, image, alpha);
  nvgRect(vg, r.x, r.y, r.w, r.h);
  nvgFillPaint(vg, imgPaint);
  nvgFill(vg);
}

void ui_draw_rect(NVGcontext *vg, float x, float y, float w, float h, NVGcolor color, float r, int width) {
  nvgBeginPath(vg);
  r > 0 ? nvgRoundedRect(vg, x, y, w, h, r) : nvgRect(vg, x, y, w, h);
  if (width) {
    nvgStrokeColor(vg, color);
    nvgStrokeWidth(vg, width);
    nvgStroke(vg);
  } else {
    nvgFillColor(vg, color);
    nvgFill(vg);
  }
}

void ui_draw_rect(NVGcontext *vg, float x, float y, float w, float h, NVGpaint &paint, float r){
  nvgBeginPath(vg);
  r > 0? nvgRoundedRect(vg, x, y, w, h, r) : nvgRect(vg, x, y, w, h);
  nvgFillPaint(vg, paint);
  nvgFill(vg);
}

static const char frame_vertex_shader[] =
#ifdef NANOVG_GL3_IMPLEMENTATION
  "#version 150 core\n"
#else
  "#version 300 es\n"
#endif
  "in vec4 aPosition;\n"
  "in vec4 aTexCoord;\n"
  "uniform mat4 uTransform;\n"
  "out vec4 vTexCoord;\n"
  "void main() {\n"
  "  gl_Position = uTransform * aPosition;\n"
  "  vTexCoord = aTexCoord;\n"
  "}\n";

static const char frame_fragment_shader[] =
#ifdef NANOVG_GL3_IMPLEMENTATION
  "#version 150 core\n"
#else
  "#version 300 es\n"
#endif
  "precision mediump float;\n"
  "uniform sampler2D uTexture;\n"
  "in vec4 vTexCoord;\n"
  "out vec4 colorOut;\n"
  "void main() {\n"
  "  colorOut = texture(uTexture, vTexCoord.xy);\n"
  "}\n";

static const mat4 device_transform = {{
  1.0,  0.0, 0.0, 0.0,
  0.0,  1.0, 0.0, 0.0,
  0.0,  0.0, 1.0, 0.0,
  0.0,  0.0, 0.0, 1.0,
}};

// frame from 4/3 to 16/9 display
static const mat4 full_to_wide_frame_transform = {{
  .75,  0.0, 0.0, 0.0,
  0.0,  1.0, 0.0, 0.0,
  0.0,  0.0, 1.0, 0.0,
  0.0,  0.0, 0.0, 1.0,
}};

void ui_nvg_init(UIState *s) {
  // init drawing
#ifdef QCOM
  // on QCOM, we enable MSAA
  s->vg = nvgCreate(0);
#else
  s->vg = nvgCreate(NVG_ANTIALIAS | NVG_STENCIL_STROKES | NVG_DEBUG);
#endif

  assert(s->vg);

  s->font_sans_regular = nvgCreateFont(s->vg, "sans-regular", "../assets/fonts/opensans_regular.ttf");
  assert(s->font_sans_regular >= 0);
  s->font_sans_semibold = nvgCreateFont(s->vg, "sans-semibold", "../assets/fonts/opensans_semibold.ttf");
  assert(s->font_sans_semibold >= 0);
  s->font_sans_bold = nvgCreateFont(s->vg, "sans-bold", "../assets/fonts/opensans_bold.ttf");
  assert(s->font_sans_bold >= 0);

  s->img_wheel = nvgCreateImage(s->vg, "../assets/img_chffr_wheel.png", 1);
  assert(s->img_wheel != 0);
  s->img_turn = nvgCreateImage(s->vg, "../assets/img_trafficSign_turn.png", 1);
  assert(s->img_turn != 0);
  s->img_face = nvgCreateImage(s->vg, "../assets/img_driver_face.png", 1);
  assert(s->img_face != 0);
  s->img_button_settings = nvgCreateImage(s->vg, "../assets/images/button_settings.png", 1);
  assert(s->img_button_settings != 0);
  s->img_button_home = nvgCreateImage(s->vg, "../assets/images/button_home.png", 1);
  assert(s->img_button_home != 0);
  s->img_battery = nvgCreateImage(s->vg, "../assets/images/battery.png", 1);
  assert(s->img_battery != 0);
  s->img_battery_charging = nvgCreateImage(s->vg, "../assets/images/battery_charging.png", 1);
  assert(s->img_battery_charging != 0);

  for(int i=0;i<=5;++i) {
    char network_asset[32];
    snprintf(network_asset, sizeof(network_asset), "../assets/images/network_%d.png", i);
    s->img_network[i] = nvgCreateImage(s->vg, network_asset, 1);
    assert(s->img_network[i] != 0);
  }

  // init gl
  s->frame_program = load_program(frame_vertex_shader, frame_fragment_shader);
  assert(s->frame_program);

  s->frame_pos_loc = glGetAttribLocation(s->frame_program, "aPosition");
  s->frame_texcoord_loc = glGetAttribLocation(s->frame_program, "aTexCoord");

  s->frame_texture_loc = glGetUniformLocation(s->frame_program, "uTexture");
  s->frame_transform_loc = glGetUniformLocation(s->frame_program, "uTransform");

  glViewport(0, 0, s->fb_w, s->fb_h);

  glDisable(GL_DEPTH_TEST);

  assert(glGetError() == GL_NO_ERROR);

  for(int i = 0; i < 2; i++) {
    float x1, x2, y1, y2;
    if (i == 1) {
      // flip horizontally so it looks like a mirror
      x1 = 0.0;
      x2 = 1.0;
      y1 = 1.0;
      y2 = 0.0;
    } else {
      x1 = 1.0;
      x2 = 0.0;
      y1 = 1.0;
      y2 = 0.0;
    }
    const uint8_t frame_indicies[] = {0, 1, 2, 0, 2, 3};
    const float frame_coords[4][4] = {
      {-1.0, -1.0, x2, y1}, //bl
      {-1.0,  1.0, x2, y2}, //tl
      { 1.0,  1.0, x1, y2}, //tr
      { 1.0, -1.0, x1, y1}, //br
    };

    glGenVertexArrays(1, &s->frame_vao[i]);
    glBindVertexArray(s->frame_vao[i]);
    glGenBuffers(1, &s->frame_vbo[i]);
    glBindBuffer(GL_ARRAY_BUFFER, s->frame_vbo[i]);
    glBufferData(GL_ARRAY_BUFFER, sizeof(frame_coords), frame_coords, GL_STATIC_DRAW);
    glEnableVertexAttribArray(s->frame_pos_loc);
    glVertexAttribPointer(s->frame_pos_loc, 2, GL_FLOAT, GL_FALSE,
                          sizeof(frame_coords[0]), (const void *)0);
    glEnableVertexAttribArray(s->frame_texcoord_loc);
    glVertexAttribPointer(s->frame_texcoord_loc, 2, GL_FLOAT, GL_FALSE,
                          sizeof(frame_coords[0]), (const void *)(sizeof(float) * 2));
    glGenBuffers(1, &s->frame_ibo[i]);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, s->frame_ibo[i]);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(frame_indicies), frame_indicies, GL_STATIC_DRAW);
    glBindBuffer(GL_ARRAY_BUFFER,0);
    glBindVertexArray(0);
  }

  s->video_rect = Rect{bdr_s, bdr_s, s->fb_w - 2 * bdr_s, s->fb_h - 2 * bdr_s};
  float zx = zoom * 2 * intrinsic_matrix.v[2] / s->video_rect.w;
  float zy = zoom * 2 * intrinsic_matrix.v[5] / s->video_rect.h;

  const mat4 frame_transform = {{
    zx, 0.0, 0.0, 0.0,
    0.0, zy, 0.0, -y_offset / s->video_rect.h * 2,
    0.0, 0.0, 1.0, 0.0,
    0.0, 0.0, 0.0, 1.0,
  }};

  s->front_frame_mat = matmul(device_transform, full_to_wide_frame_transform);
  s->rear_frame_mat = matmul(device_transform, frame_transform);
}