From feac7aea6995d322a9dfbe759799acd86fc724e2 Mon Sep 17 00:00:00 2001
From: Jeremy Hu <huxingyi@msn.com>
Date: Mon, 16 Jan 2017 22:19:47 +0930
Subject: [PATCH] Add mouse position to world coord translation.

---
 src/draw.h     |  1 +
 src/render.cpp | 58 +++++++++++++++++++++++++++++++++++++++++++++++---
 src/render.h   |  5 ++++-
 3 files changed, 60 insertions(+), 4 deletions(-)

diff --git a/src/draw.h b/src/draw.h
index 742f3c9e..05a3cde8 100644
--- a/src/draw.h
+++ b/src/draw.h
@@ -22,6 +22,7 @@ int drawText(int x, int y, char *text);
 int drawPrintf(int x, int y, const char *fmt, ...);
 int drawDebugPrintf(const char *fmt, ...);
 void drawDebugPoint(vec3 *origin, int colorIndex);
+void drawTestUnproject(void);
 
 #ifdef __cplusplus
 }
diff --git a/src/render.cpp b/src/render.cpp
index fc0d8c15..134804db 100644
--- a/src/render.cpp
+++ b/src/render.cpp
@@ -17,7 +17,7 @@ static const float bmeshBallColors[][4] {
 
 static const float bmeshBoneColor[3] = {1, 1, 0};
 
-static QGLWidget *_this = 0;
+static Render *_this = 0;
 static int debugOutputTop = 0;
 
 int drawDebugPrintf(const char *fmt, ...) {
@@ -35,7 +35,14 @@ int drawDebugPrintf(const char *fmt, ...) {
 }
 
 static int drawBmeshBall(bmesh *bm, bmeshBall *ball) {
-  glColor4fv(bmeshBallColors[ball->type]);
+  float color[4];
+  memcpy(color, bmeshBallColors[ball->type], sizeof(color));
+  vec3 mousePos[] = {{_this->mouseWorldX, _this->mouseWorldY,
+    _this->mouseWorldZ}};
+  if (vec3Distance(&ball->position, mousePos) <= ball->radius * 5) {
+    color[3] = 1;
+  }
+  glColor4fv(color);
   drawSphere(&ball->position, ball->radius, 36, 24);
   return 0;
 }
@@ -43,7 +50,7 @@ static int drawBmeshBall(bmesh *bm, bmeshBall *ball) {
 static void drawBmeshBallRecursively(bmesh *bm, bmeshBall *ball) {
   bmeshBallIterator iterator;
   bmeshBall *child;
-  //drawBmeshBall(bm, ball);
+  drawBmeshBall(bm, ball);
   for (child = bmeshGetBallFirstChild(bm, ball, &iterator);
       child;
       child = bmeshGetBallNextChild(bm, ball, &iterator)) {
@@ -213,6 +220,31 @@ void Render::initializeGL() {
   drawInit();
 }
 
+void screenCoordsToWorld(float winX, float winY,
+    float *worldX, float *worldY, float *worldZ){
+  GLint viewport[4];
+  GLdouble modelview[16];
+  GLdouble projection[16];
+  GLfloat winZ = 0;
+  GLdouble x, y, z;
+
+  glGetDoublev(GL_MODELVIEW_MATRIX, modelview);
+  glGetDoublev(GL_PROJECTION_MATRIX, projection);
+  glGetIntegerv(GL_VIEWPORT, viewport);
+
+  winX = (float)winX;
+  winY = (float)viewport[3] - (float)winY;
+  winZ = 0;
+
+  gluUnProject((GLdouble)winX, (GLdouble)winY, (GLdouble)winZ,
+    (const GLdouble *)modelview, (const GLdouble *)projection, viewport,
+    &x, &y, &z);
+  
+  *worldX = (float)x;
+  *worldY = (float)y;
+  *worldZ = (float)z;
+}
+
 #include "../data/bmesh_test_2.h"
 
 void Render::paintGL() {
@@ -236,6 +268,12 @@ void Render::paintGL() {
   drawGrid(10, 1);
 
   glEnable(GL_LIGHTING);
+  
+  screenCoordsToWorld(_this->mouseX, _this->mouseY,
+    &_this->mouseWorldX, &_this->mouseWorldY, &_this->mouseWorldZ);
+  glColor3f(0.0f, 0.0f, 0.0f);
+  drawDebugPrintf("%d,%d -> %f,%f,%f", _this->mouseX, _this->mouseY,
+    _this->mouseWorldX, _this->mouseWorldY, _this->mouseWorldZ);
 
   if (0 == bm) {
     bmeshBall ball;
@@ -312,6 +350,9 @@ void Render::paintGL() {
       }*/
     }
   }
+  
+  //glColor3f(0.0f, 0.0f, 0.0f);
+  //drawTestUnproject();
 
   glPopMatrix();
   
@@ -332,6 +373,17 @@ void Render::resizeGL(int w, int h) {
   glLoadIdentity();
 }
 
+/*
+void drawTestUnproject(void) {
+  float worldX, worldY, worldZ;
+  if (_this) {
+    screenCoordsToWorld(_this->mouseX, _this->mouseY, &worldX, &worldY, &worldZ);
+    glColor3f(0.0f, 0.0f, 0.0f);
+    drawDebugPrintf("%d,%d -> %f,%f,%f", _this->mouseX, _this->mouseY,
+      worldX, worldY, worldZ);
+  }
+}*/
+
 void Render::mousePressEvent(QMouseEvent *event) {
   mouseX = event->x();
   mouseY = event->y();
diff --git a/src/render.h b/src/render.h
index ff2f9665..6e7cae9a 100644
--- a/src/render.h
+++ b/src/render.h
@@ -18,9 +18,12 @@ protected:
   void mouseMoveEvent(QMouseEvent *event);
   void wheelEvent(QWheelEvent * event);
 
-private:
+public:
   int mouseX;
   int mouseY;
+  float mouseWorldX;
+  float mouseWorldY;
+  float mouseWorldZ;
   float cameraAngleX;
   float cameraAngleY;
   float cameraDistance;