+#include "GL/glew.h"
#include "debug.hpp"
-#include "simulation.h"
#include "program.hpp"
-#include <GL/glew.h>
+#include "simulation.hpp"
#include <GLUT/glut.h>
+#include <array>
+#include <chrono>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <glm/ext.hpp>
#include <glm/glm.hpp>
+#include <sys/stat.h>
#include <vector>
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+enum Mode { render, debugContDist, debugColor, debugProbExt, debugProbAct };
+Mode curMode = render;
+
using namespace std;
using namespace glm;
-// calculate continuous distribution
-void calcContDist(Clouds *clds);
-
-float w(int i, int j, int k) { return 1; }
-
-const float metaballR = 1;
-float metaballField(float r) {
- if (r > metaballR)
+const float metaballR = 1.f / 16.f;
+inline float metaballField(float r) {
+ if (r > 1)
return 0;
- const float a = r / metaballR;
+ const float a = r / (1);
return (-4.f / 9.f * powf(a, 6)) + (17.f / 9.f * powf(a, 4)) -
(22.f / 9.f * powf(a, 2)) + 1;
}
-/* const float normalizationFactor = 748.f / 405.f * M_PI * metaballR; */
-
-void calcContDist(Clouds *clds, float t) {
- const int i0 = 2, j0 = 2, k0 = 2, t0 = 2;
- const float divisor =
- 1.f / ((2 * t0 + 1) * (2 * k0 + 1) * (2 * j0 + 1) * (2 * i0 + 1));
- float sum = 0;
- for (int i = 0; i < CLOUD_DIM; i++) {
- for (int j = 0; j < CLOUD_DIM; j++) {
- for (int k = 0; k < CLOUD_DIM; k++) {
-
- // inner sums
- /* for (int tp = -t0, tp < t0; tp++) { */
- for (int ip = -i0; ip < i0; ip++) {
- for (int jp = -j0; jp < j0; jp++) {
- for (int kp = -k0; kp < k0; kp++) {
-
- sum += w(ip, jp, kp) * (float)clds->cld[i + ip][j + jp][k + kp];
- }
- }
- }
- /* } */
-
- clds->contDist[i][j][k] = sum / divisor;
- }
- }
- }
-}
+const float normalizationFactor = (748.f / 405.f) * M_PI;
void checkError() {
if (GLenum e = glGetError()) {
}
}
-vector<vec4> bbColors;
-
-GLuint bbProg;
+GLuint bbProg, sunProg;
GLuint bbVao;
// Here we need to generate n_q textures for different densities of metaballs
// These textures then go on the billboards
// The texture stores attenuation ratio?
-#define NQ 1
+#define NQ 64
GLuint bbTexIds[NQ];
// Stores attenuation ratio inside r channel
// Should be highest value at center
void precalculateBillboardTextures() {
+ fprintf(stderr, "Calculating billboard textures...\n");
+ glGenTextures(NQ, bbTexIds);
+
+ for (int d = 0; d < NQ; d++) {
float data[32 * 32];
+ for (int j = 0; j < 32; j++) {
+ for (int i = 0; i < 32; i++) {
// 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 + 2.f * (distance(vec2(i, j), vec2(16, 16)) / 16));
+ float r = distance(vec2(i, j), vec2(16, 16)) / 16;
+ float density = (float)d / NQ;
+ data[i + j * 32] =
+ 1 - fmin(1, (3 * density * (metaballField(r) / normalizationFactor)));
+ }
+ }
- glGenTextures(NQ, bbTexIds);
+ mkdir("bbtex", 0777);
+ char path[32];
+ snprintf(path, 32, "bbtex/%i.tga", d);
+ saveGrayscale(data, 32, 32, path);
- for (int i = 0; i < NQ; i++) {
- glBindTexture(GL_TEXTURE_2D, bbTexIds[i]);
- checkError();
+ glBindTexture(GL_TEXTURE_2D, bbTexIds[d]);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, 32, 32, 0, GL_RED, GL_FLOAT, data);
glGenerateMipmap(GL_TEXTURE_2D); // required, otherwise texture is blank
- checkError();
+ fprintf(stderr, "\r%i out of %i densities calculated%s", d + 1, NQ,
+ d == NQ - 1 ? "\n" : "");
}
}
struct Metaball {
vec3 pos;
- float r;
+ ivec3 coords;
+ /** Density */
+ float d;
+ vec4 col;
};
-// TODO: why is the x axis flipped??
-/* vector<Metaball> metaballs = {{{-0.5, 0.5, 0.5}, 0.25}, */
-/* {{-0.3, 0.5, 0.3}, 0.25}}; */
-vector<Metaball> metaballs = {{{0, 0, 0.5}, 1.f},
- {{0, 0.3, 0.3}, 0.7f}};
+array<Metaball, CLOUD_DIM_X * CLOUD_DIM_Y * CLOUD_DIM_Z> metaballs;
+
+const float cloudScale = metaballR;
+const float metaballScale = metaballR * 1.5f;
Clouds cs;
void calculateMetaballs() {
- /* stepClouds(&cs); */
- metaballs.clear();
- 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); */
+ stepClouds(&cs);
+ /* 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); */
/* } */
- /* } */
- /* } */
- /* } */
- fprintf(stderr, "num metaballs: %lu\n", metaballs.size());
+ for (int i = 0; i < CLOUD_DIM_X; i++) {
+ for (int j = 0; j < CLOUD_DIM_Y; j++) {
+ for (int k = 0; k < CLOUD_DIM_Z; k++) {
+ Metaball m = {vec3(i, j, k) * vec3(cloudScale), {i, j, k}};
+ /* m.pos = (m.pos * vec3(2)) - (cloudScale / 2); */
+ m.pos -= vec3(CLOUD_DIM_X, CLOUD_DIM_Y, CLOUD_DIM_Z) * cloudScale / 2.f;
+ m.d = cs.q[i][j][k];
+ /* m.d = 0; */
+ metaballs[i * CLOUD_DIM_Y * CLOUD_DIM_Z + j * CLOUD_DIM_Z + k] = m;
+ }
+ }
+ }
+ /* for (int z = 0; z < CLOUD_DIM_Z; z++) */
+ /* metaballs[32 * CLOUD_DIM_Y * CLOUD_DIM_Z + 32 * CLOUD_DIM_Z + z].d = 1;
+ */
}
-vec3 sunPos = {0, 2, 2}, sunDir = {0, -1, -1};
-vec3 camPos = {0, 0, -5}, viewPos = {0, 0, 0};
+vec3 sunPos = {0, 5, 0}, sunDir = {0, -1, 0};
+size_t envColorIdx = 0;
+// First color is sun color, second is sky color
+std::array<std::array<vec4, 2>, 3> envColors{
+ {{vec4(1, 1, 1, 1), vec4(0.9, 1, 1, 1)},
+ {vec4(0.939, 0.632, 0.815, 1), vec4(0.9, 1, 1, 1)},
+ {vec4(0.999, 0.999, 0.519, 1), vec4(0.981, 0.667, 0.118, 1)}}};
+vec3 camPos = {0, 0, -3}, viewPos = {0, 0, 0};
mat4 proj; // projection matrix
mat4 view; // view matrix
float znear = 0.001, zfar = 1000;
-float width = 600, height = 400;
-float aspect = width / height;
+// for performance with glReadPixels these should be powers of 2!
+float width = 1200, height = 800;
void setProjectionAndViewUniforms(GLuint progId) {
GLuint projLoc = glGetUniformLocation(progId, "projection");
return m;
}
-GLuint attenuationTex;
+#define PBO
-void shadeClouds() {
+/* const int shadeWidth = 256, shadeHeight = 256; */
+const int shadeWidth = 256, shadeHeight = 256;
+
+#ifdef PBO
+const int numPbos = 64;
+GLuint pboBufs[numPbos];
+GLbyte sink[shadeWidth * shadeHeight * 4];
+
+void inline mapPixelRead(int pboBuf, int metaball) {
+ glBindBuffer(GL_PIXEL_PACK_BUFFER, pboBufs[pboBuf]);
+ GLubyte *src = (GLubyte *)glMapBufferRange(GL_PIXEL_PACK_BUFFER, 0, 4 * sizeof(GLubyte),
+ GL_MAP_READ_BIT);
+ vec4 pixel = vec4(src[0], src[1], src[2], src[3]) / vec4(255.f);
+ glUnmapBuffer(GL_PIXEL_PACK_BUFFER);
- bbColors.clear();
+ glBindBuffer(GL_PIXEL_PACK_BUFFER, 0);
+
+ // Multiply the pixel value by the sunlight color.
+ pixel *= envColors[envColorIdx][0];
+
+ // Store the color for the previous set of pixels
+ metaballs[metaball].col = pixel;
+}
+
+#endif
+
+void shadeClouds() {
glDisable(GL_DEPTH_TEST);
// shaderOutput * 0 + buffer * shader alpha
});
glActiveTexture(GL_TEXTURE0);
- glBindTexture(GL_TEXTURE_2D, bbTexIds[0]);
glUniform1i(glGetUniformLocation(bbProg, "tex"), 0);
GLuint modelLoc = glGetUniformLocation(bbProg, "model");
+ glUniform1i(glGetUniformLocation(bbProg, "debug"), 0);
- for (auto k : metaballs) {
+ glViewport(0, 0, shadeWidth, shadeHeight);
+
+#ifdef PBO
+ int pboIdx = 0;
+#endif
+
+ auto begin_time = std::chrono::system_clock::now();
+ size_t i = 0;
+ for (auto &k : metaballs) {
+ /* fprintf(stderr, "\rShading metaball %lu/%lu...", i, metaballs.size()); */
// place the billboard at the center of k
- mat4 model = scale(translate(mat4(1), k.pos), vec3(k.r) * 2.f);
+ mat4 model = translate(mat4(1), k.pos);
// rotate the billboard so that its normal is oriented to the sun
model = faceView(model);
+ model = scale(model, vec3(metaballScale));
+
glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
// Set the billboard color as RGBA = (1.0, 1.0, 1.0, 1.0).
// i.e. multiply rather than add
// but glTexEnv is for the old fixed function pipeline --
// need to just tell our fragment shader then to modulate
+ int dIdx = k.d * NQ;
+ glBindTexture(GL_TEXTURE_2D, bbTexIds[dIdx]);
glUniform1i(glGetUniformLocation(bbProg, "modulate"), 1);
// Render the billboard.
// 1. First get position in opengl screen space: from [-1,1]
// 2. Normalize to [0,1]
// 3. Multiply by (width * height)
- vec2 screenPos = ((vec2(proj * view * model * vec4(0,0,0,1)) + vec2(1)) / vec2(2))
- * vec2(width, height);
+ ivec2 screenPos =
+ ((vec2(proj * view * model * vec4(0, 0, 0, 1)) + vec2(1)) / vec2(2)) *
+ vec2(shadeWidth, shadeHeight);
+
+#ifndef PBO
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); */
+ // TODO: This is a huge bottleneck
+ glReadPixels(screenPos.x, screenPos.y, 1, 1, GL_RGBA, GL_FLOAT, &pixel);
// Multiply the pixel value by the sunlight color.
- vec4 sunColor = {1, 1, 0.9, 1};
- pixel *= sunColor;
+ pixel *= envColors[envColorIdx][0];
// Store the color into an array C[k] as the color of the billboard.
- bbColors.push_back(pixel);
+ k.col = pixel;
+#else
+
+ glBindBuffer(GL_PIXEL_PACK_BUFFER, pboBufs[pboIdx]);
+ glReadPixels(screenPos.x, screenPos.y, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE,
+ NULL);
+ // TODO: use this
+ /* glReadPixels(0, 0, shadeWidth, shadeHeight, GL_RGBA, GL_UNSIGNED_BYTE, */
+ /* NULL); */
+
+ int nextPbo = (pboIdx + 1) % numPbos;
+ if (i >= numPbos - 1) {
+ // start mapping the read values back
+ mapPixelRead(nextPbo, i - numPbos + 1);
}
+ pboIdx = nextPbo;
+#endif
+
+ i++;
+ }
+ /* fprintf(stderr, "\n"); */
+
+#ifdef PBO
+ // sink remaining reads
+ for (int i = 0; i < numPbos; i++) {
+ mapPixelRead(i, metaballs.size() - numPbos + i);
+ }
+#endif
+
+ auto elapsed = std::chrono::system_clock::now() - begin_time;
+ double elapsed_seconds =
+ std::chrono::duration_cast<std::chrono::duration<double>>(elapsed)
+ .count();
+ fprintf(stderr, "Time taken to shade: %fs\n", elapsed_seconds);
saveFBO();
checkError();
+ glViewport(0, 0, width, height);
}
-void renderObject() {}
+void renderObject() {
+ glDisable(GL_BLEND);
+ // render the sun
+ glUseProgram(sunProg);
+ mat4 model = translate(mat4(1), sunPos);
+ model = lookAt(sunPos, sunPos + sunDir, {0, 1, 0}) * model;
+ model = translate(scale(translate(model, -sunPos), vec3(0.3)), sunPos);
+ glUniformMatrix4fv(glGetUniformLocation(sunProg, "model"), 1, GL_FALSE,
+ glm::value_ptr(model));
+ glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
+}
void renderClouds() {
+ glUseProgram(bbProg);
+
// Sort metaballs in descending order from the viewpoint
sort(metaballs.begin(), metaballs.end(), [](Metaball &a, Metaball &b) {
return distance(camPos, a.pos) > distance(camPos, b.pos);
});
+ glUniform1i(glGetUniformLocation(bbProg, "debug"), curMode != render);
+
glDisable(GL_DEPTH_TEST);
glEnable(GL_BLEND);
// shaderOutput * 1 + buffer * shader alpha
glBlendFunc(GL_ONE, GL_SRC_ALPHA);
+
+ /* glBlendColor(1.f,1.f,1.f,1.f); */
+ /* glBlendFuncSeparate(GL_ONE, GL_SRC_ALPHA, GL_CONSTANT_ALPHA, GL_SRC_ALPHA);
+ */
+
+ glActiveTexture(GL_TEXTURE0);
+ glUniform1i(glGetUniformLocation(bbProg, "tex"), 0);
+
for (int i = 0; i < metaballs.size(); i++) {
Metaball k = metaballs[i];
GLuint modelLoc = glGetUniformLocation(bbProg, "model");
// Place the billboard at the center of the corresponding metaball n.
- mat4 model = scale(translate(mat4(1), k.pos), vec3(k.r) * 2.f);
+ mat4 model = translate(mat4(1), k.pos);
// Rotate the billboard so that its normal is oriented to the viewpoint.
model = faceView(model);
+ model = scale(model, vec3(metaballScale));
+
glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
// Set the billboard color as C[n].
- 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; */
- bbColors[i].w = 1;
+ k.col.w = 1;
glUniform4fv(glGetUniformLocation(bbProg, "color"), 1,
- glm::value_ptr(bbColors[i]));
+ glm::value_ptr(k.col));
// Map the billboard texture.
- glActiveTexture(GL_TEXTURE0);
- glBindTexture(GL_TEXTURE_2D, bbTexIds[0]);
- glUniform1i(glGetUniformLocation(bbProg, "tex"), 0);
+ int dIdx = k.d * (NQ - 1);
+ glBindTexture(GL_TEXTURE_2D, bbTexIds[dIdx]);
// Don't modulate it -- blend it
glUniform1i(glGetUniformLocation(bbProg, "modulate"), 0);
+ glUniform1f(glGetUniformLocation(bbProg, "debugColor"),
+ curMode == debugColor);
+ if (curMode != render) {
+ float debugVal = 0;
+ if (curMode == debugContDist)
+ debugVal = k.d;
+ else if (curMode == debugProbAct)
+ debugVal = cs.p_act[k.coords.x][k.coords.y][k.coords.z] / P_ACT;
+ else if (curMode == debugProbExt)
+ debugVal = cs.p_ext[k.coords.x][k.coords.y][k.coords.z] / P_EXT;
+ glUniform1f(glGetUniformLocation(bbProg, "debugVal"), debugVal);
+ glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+ model = scale(model, vec3(0.1));
+ glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
+ }
+
// Render the billboard with the blending function.
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
}
}
+bool curBeenShaded = false;
+
void display() {
+ if (!curBeenShaded && (curMode == render || curMode == debugColor)) {
// 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);
+ view = glm::lookAt(sunPos + sunDir * vec3(100.f), sunPos, {0, 0, 1});
+ // TODO: calculate bounds so everything is covered
+ proj = glm::ortho(2.5f, -2.5f, -2.5f, 2.5f, znear, 10000.f);
+ glUseProgram(bbProg);
setProjectionAndViewUniforms(bbProg);
glClearColor(1, 1, 1, 1);
glClear(GL_COLOR_BUFFER_BIT);
shadeClouds();
+ curBeenShaded = true;
+ }
view = glm::lookAt(camPos, viewPos, {0, 1, 0});
+ const float aspect = width / height;
proj = glm::perspective(45.f, aspect, znear, zfar);
+ glUseProgram(sunProg);
+ setProjectionAndViewUniforms(sunProg);
+ glUseProgram(bbProg);
setProjectionAndViewUniforms(bbProg);
- glClearColor(0.83,1,1,1); // background color
+ vec4 skyColor = envColors[envColorIdx][1];
+ glClearColor(skyColor.r, skyColor.g, skyColor.b,
+ skyColor.a); // background color
glClear(GL_COLOR_BUFFER_BIT);
renderObject(); // render things that aren't clouds
renderClouds();
bool needsRedisplay = false;
void timer(int _) {
- /* calculateMetaballs(); */
if (needsRedisplay) {
glutPostRedisplay();
- needsRedisplay = false;
}
+ needsRedisplay = false;
glutTimerFunc(16, timer, 0);
}
void keyboard(unsigned char key, int x, int y) {
if (key == ' ') {
calculateMetaballs();
- glutPostRedisplay();
+ needsRedisplay = true;
+ curBeenShaded = false;
+ }
+ if (key == '0') {
+ curMode = render;
+ needsRedisplay = true;
+ }
+ if (key == '1') {
+ curMode = debugContDist;
+ needsRedisplay = true;
+ }
+ if (key == '2') {
+ curMode = debugColor;
+ needsRedisplay = true;
+ }
+ if (key == '3') {
+ curMode = debugProbAct;
+ needsRedisplay = true;
+ }
+ if (key == '4') {
+ curMode = debugProbExt;
+ needsRedisplay = true;
+ }
+ if (key == 's') {
+ envColorIdx = (envColorIdx + 1) % envColors.size();
+ needsRedisplay = true;
+ curBeenShaded = false;
}
}
firstMouse = false;
}
float dx = x - prevMouseX, dy = y - prevMouseY;
- prevMouseX = x; prevMouseY = y;
- const vec3 origin(0,18,0);
+ prevMouseX = x;
+ prevMouseY = y;
+ const vec3 origin(0, 0, 0);
const float sensitivity = 0.003f;
auto camMat = translate(mat4(1), origin + camPos);
auto rotation = rotate(rotate(mat4(1), -dx * sensitivity, {0, 1, 0}),
needsRedisplay = true;
}
+void passiveMotion(int x, int y) {
+ prevMouseX = x;
+ prevMouseY = y;
+}
+
+void reshape(int w, int h) {
+ width = w;
+ height = h;
+}
+
int main(int argc, char **argv) {
glutInit(&argc, argv);
- glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGB |
+ glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA | GLUT_ALPHA |
GLUT_3_2_CORE_PROFILE);
glutInitWindowSize(width, height);
glutCreateWindow("Clouds");
glutDisplayFunc(display);
+ glutReshapeFunc(reshape);
+ glutKeyboardFunc(keyboard);
+ glutMotionFunc(motion);
+ glutPassiveMotionFunc(passiveMotion);
+ glutTimerFunc(16, timer, 0);
glewInit();
Program prog("billboardvert.glsl", "billboardfrag.glsl");
-
bbProg = prog.progId;
- glUseProgram(bbProg);
+ Program sProg("sunvert.glsl", "sunfrag.glsl");
+ sunProg = sProg.progId;
glGenVertexArrays(1, &bbVao);
+ glUseProgram(sunProg);
+ glBindVertexArray(bbVao);
+ glUseProgram(bbProg);
glBindVertexArray(bbVao);
GLuint vbos[2];
glGenBuffers(2, vbos);
initClouds(&cs);
calculateMetaballs();
- glGenTextures(1, &attenuationTex);
-
- glutKeyboardFunc(keyboard);
- glutMotionFunc(motion);
- glutTimerFunc(16, timer, 0);
-
- // set up billboard prog
+#ifdef PBO
+ // setup PBOs for buffering readPixels
+ glGenBuffers(numPbos, pboBufs);
+ for (int i = 0; i < numPbos; i++) {
+ glBindBuffer(GL_PIXEL_PACK_BUFFER, pboBufs[i]);
+ glBufferData(GL_PIXEL_PACK_BUFFER, shadeWidth * shadeHeight * 4, NULL,
+ GL_DYNAMIC_READ);
+ }
+ glBindBuffer(GL_PIXEL_PACK_BUFFER, 0);
+#endif
glutMainLoop();