Fix billboard orientation

diff --git a/Makefile b/Makefile
index fcdd4226d889e68a55d9d9ed08ca4f9aa99b87b3..67b688d8f657a20bf428114d10798df30a3f8cb8 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 clouds: clouds.cpp program.cpp simulation.cpp
-       clang++ -std=c++17 $^ -Ofast -o $@ \
+       clang++ -std=c++17 $^ -o $@ \
                -Wall -g \
                -I/usr/local/include -L/usr/local/lib \
                -framework OpenGL -framework glut -lglew

diff --git a/clouds.cpp b/clouds.cpp
index e406f5c6b7500aa06d1c055a819834a43c677ae4..d5c8f6ad628ff1e1c23d22a09abfdd5e7a180bcd 100644 (file)
--- a/clouds.cpp
+++ b/clouds.cpp
@@ -84,7 +84,7 @@ void precalculateBillboardTextures() {
   // TODO: properly calculate this instead of whatever this is
   for (int j = 0; j < 32; j++)
     for (int i = 0; i < 32; i++)
-      data[i + j * 32] = fmin(1.f, 0.5f + 1.f * (distance(vec2(i, j), vec2(16, 16)) / 16));
+      data[i + j * 32] = fmin(1.f, 0.5f + 2.f * (distance(vec2(i, j), vec2(16, 16)) / 16));
 
   glGenTextures(NQ, bbTexIds);
 
@@ -112,30 +112,33 @@ vector<Metaball> metaballs = {{{0, 0, 0.5}, 1.f},
 Clouds cs;
 
 void calculateMetaballs() {
-  stepClouds(&cs);
+  /* stepClouds(&cs); */
   metaballs.clear();
-  for (int i = 0; i < CLOUD_DIM; i++) {
-    for (int j = 0; j < CLOUD_DIM; j++) {
-      for (int k = 0; k < CLOUD_DIM; k++) {
-        if (cs.cld[i][j][k]) {
-          /* float x = (float)rand()/(float)(RAND_MAX); */
-          /* float y = (float)rand()/(float)(RAND_MAX); */
-          /* float z = (float)rand()/(float)(RAND_MAX); */
-          /* float r = (float)rand()/(float)(RAND_MAX); */
-          /* Metaball m = {{x,y, 0.3 + z * 0.5}, r}; */
-          /* metaballs.push_back(m); */
-          Metaball m = {{i / (float)CLOUD_DIM, j / (float)CLOUD_DIM, k / (float)CLOUD_DIM},
-                        1.f / (float)CLOUD_DIM };
-          m.pos = (m.pos * vec3(2)) - vec3(1);
+  for (int i = 0; i < 256; i++) {
+    float x = ((float)rand()/(float)(RAND_MAX) - 0.5) * 2;
+    float y = ((float)rand()/(float)(RAND_MAX) - 0.5) * 2;
+    float z = ((float)rand()/(float)(RAND_MAX) - 0.5) * 2;
+    float r = (float)rand()/(float)(RAND_MAX) * 1;
+    Metaball m = {{x,y,z}, r};
     metaballs.push_back(m);
   }
-      }
-    }
-  }
+  /* for (int i = 0; i < CLOUD_DIM; i++) { */
+  /*   for (int j = 0; j < CLOUD_DIM; j++) { */
+  /*     for (int k = 0; k < CLOUD_DIM; k++) { */
+  /*       if (cs.cld[i][j][k]) { */
+  /*         Metaball m = {{i / (float)CLOUD_DIM, j / (float)CLOUD_DIM, k / (float)CLOUD_DIM}, */
+  /*                       1.f / (float)CLOUD_DIM }; */
+  /*         m.pos = (m.pos * vec3(2)) - vec3(1); */
+  /*         metaballs.push_back(m); */
+  /*       } */
+  /*     } */
+  /*   } */
+  /* } */
   fprintf(stderr, "num metaballs: %lu\n", metaballs.size());
 }
 
-vec3 sunPos = {0, 2, 2}, viewPos = {0, 0, 0}, lookPos = {0, 0, 1};
+vec3 sunPos = {0, 2, 2}, sunDir = {0, -1, -1};
+vec3 camPos = {0, 0, -5}, viewPos = {0, 0, 0};
 mat4 proj; // projection matrix
 mat4 view; // view matrix
 float znear = 0.001, zfar = 1000;
@@ -152,7 +155,7 @@ void setProjectionAndViewUniforms(GLuint progId) {
 
 /** Orientates the transformation matrix to face the camera in the view matrix
  */
-void faceView(mat4 m) {
+mat4 faceView(mat4 m) {
   m[0][0] = view[0][0];
   m[0][1] = view[1][0];
   m[0][2] = view[2][0];
@@ -162,6 +165,7 @@ void faceView(mat4 m) {
   m[2][0] = view[0][2];
   m[2][1] = view[1][2];
   m[2][2] = view[2][2];
+  return m;
 }
 
 GLuint attenuationTex;
@@ -191,7 +195,7 @@ void shadeClouds() {
     mat4 model = scale(translate(mat4(1), k.pos), vec3(k.r) * 2.f);
 
     // rotate the billboard so that its normal is oriented to the sun
-    faceView(model);
+    model = faceView(model);
 
     glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
 
@@ -217,6 +221,7 @@ void shadeClouds() {
                       * vec2(width, height);
     vec4 pixel;
     glReadPixels(screenPos.x, screenPos.y, 1, 1, GL_RGBA, GL_FLOAT, value_ptr(pixel));
+    /* if (pixel.g == 0 && pixel.b == 0) abort(); */
     /* fprintf(stderr, "pixel:"); */
     /* dump(pixel); */
 
@@ -237,7 +242,7 @@ void renderObject() {}
 void renderClouds() {
   // Sort metaballs in descending order from the viewpoint
   sort(metaballs.begin(), metaballs.end(), [](Metaball &a, Metaball &b) {
-    return distance(viewPos, a.pos) > distance(viewPos, b.pos);
+    return distance(camPos, a.pos) > distance(camPos, b.pos);
   });
 
   glDisable(GL_DEPTH_TEST);
@@ -252,13 +257,13 @@ void renderClouds() {
     // Place the billboard at the center of the corresponding metaball n.
     mat4 model = scale(translate(mat4(1), k.pos), vec3(k.r) * 2.f);
     // Rotate the billboard so that its normal is oriented to the viewpoint.
-    faceView(model);
+    model = faceView(model);
 
     glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
 
     // Set the billboard color as C[n].
-    /* fprintf(stderr, "bbColors[i]: "); */
-    /* dump(bbColors[i]); */
+    fprintf(stderr, "bbColors[i]: ");
+    dump(bbColors[i]);
     /* bbColors[i].x = 1 - bbColors[i].x; */
     /* bbColors[i].y = 1 - bbColors[i].y; */
     /* bbColors[i].z = 1 - bbColors[i].z; */
@@ -280,7 +285,8 @@ void renderClouds() {
 }
 
 void display() {
-  view = glm::lookAt(sunPos, viewPos, {0, 1, 0});
+  // TODO: find a way to make sure there's no clipping
+  view = glm::lookAt(sunPos + sunDir * vec3(20), sunPos, {0, 1, 0});
   proj = glm::ortho(1.f * aspect, -1.f * aspect, -1.f, 1.f, znear, zfar);
   setProjectionAndViewUniforms(bbProg);
 
@@ -288,11 +294,11 @@ void display() {
   glClear(GL_COLOR_BUFFER_BIT);
   shadeClouds();
 
-  view = glm::lookAt(viewPos, lookPos, {0, 1, 0});
-  proj = glm::perspective(60.f, aspect, znear, zfar);
+  view = glm::lookAt(camPos, viewPos, {0, 1, 0});
+  proj = glm::perspective(45.f, aspect, znear, zfar);
   setProjectionAndViewUniforms(bbProg);
 
-  glClearColor(0.73,1,1,1); // background color
+  glClearColor(0.83,1,1,1); // background color
   glClear(GL_COLOR_BUFFER_BIT);
   renderObject();               // render things that aren't clouds
   renderClouds();
@@ -300,10 +306,14 @@ void display() {
   glutSwapBuffers();
 }
 
+bool needsRedisplay = false;
 void timer(int _) {
   /* calculateMetaballs(); */
-  /* glutPostRedisplay(); */
-  /* glutTimerFunc(16, timer, 0); */
+  if (needsRedisplay) {
+    glutPostRedisplay();
+    needsRedisplay = false;
+  }
+  glutTimerFunc(16, timer, 0);
 }
 
 void keyboard(unsigned char key, int x, int y) {
@@ -313,6 +323,26 @@ void keyboard(unsigned char key, int x, int y) {
        }
 }
 
+int prevMouseX, prevMouseY;
+bool firstMouse = true;
+void motion(int x, int y) {
+       if (firstMouse) {
+               prevMouseX = x;
+               prevMouseY = y;
+               firstMouse = false;
+       }
+       float dx = x - prevMouseX, dy = y - prevMouseY;
+       prevMouseX = x; prevMouseY = y;
+       const vec3 origin(0,18,0);
+       const float sensitivity = 0.003f;
+       auto camMat = translate(mat4(1), origin + camPos);
+       auto rotation = rotate(rotate(mat4(1), -dx * sensitivity, {0, 1, 0}),
+                       -dy * sensitivity, {1, 0, 0});
+       auto rotAroundOrig = camMat * rotation * translate(mat4(1), origin - camPos);
+       camPos = rotAroundOrig * glm::vec4(camPos, 0);
+    needsRedisplay = true;
+}
+
 int main(int argc, char **argv) {
   glutInit(&argc, argv);
   glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGB |
@@ -357,6 +387,7 @@ int main(int argc, char **argv) {
   glGenTextures(1, &attenuationTex);
 
   glutKeyboardFunc(keyboard);
+  glutMotionFunc(motion);
   glutTimerFunc(16, timer, 0);
 
   // set up billboard prog