X-Git-Url: https://git.lukelau.me/?p=clouds.git;a=blobdiff_plain;f=clouds.cpp;h=b8ea3f0071cb0f0e5ce34bdfd48e44b17151edbd;hp=52b3053812d8f16416361e519270e8df1bd23dfa;hb=HEAD;hpb=0258cd283dc666dd89f620179f57343662ab5d1a diff --git a/clouds.cpp b/clouds.cpp index 52b3053..b8ea3f0 100644 --- a/clouds.cpp +++ b/clouds.cpp @@ -1,9 +1,10 @@ +#include "GL/glew.h" #include "debug.hpp" #include "program.hpp" -#include "simulation.h" -#include +#include "simulation.hpp" #include #include +#include #include #include #include @@ -14,21 +15,22 @@ #pragma clang diagnostic ignored "-Wdeprecated-declarations" -bool debugContDist = false; +enum Mode { render, debugContDist, debugColor, debugProbExt, debugProbAct }; +Mode curMode = render; using namespace std; using namespace glm; -const float metaballR = 1.5f; +const float metaballR = 1.f / 16.f; inline float metaballField(float r) { - if (r > metaballR) + 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; +const float normalizationFactor = (748.f / 405.f) * M_PI; void checkError() { if (GLenum e = glGetError()) { @@ -37,7 +39,7 @@ void checkError() { } } -GLuint bbProg; +GLuint bbProg, sunProg; GLuint bbVao; // Here we need to generate n_q textures for different densities of metaballs @@ -61,7 +63,8 @@ void precalculateBillboardTextures() { float r = distance(vec2(i, j), vec2(16, 16)) / 16; float density = (float)d / NQ; data[i + j * 32] = - 1 - (density * metaballField(r) / normalizationFactor); + 1 - + fmin(1, (3 * density * (metaballField(r) / normalizationFactor))); } } @@ -71,13 +74,10 @@ void precalculateBillboardTextures() { saveGrayscale(data, 32, 32, path); glBindTexture(GL_TEXTURE_2D, bbTexIds[d]); - checkError(); 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" : ""); } @@ -85,13 +85,16 @@ void precalculateBillboardTextures() { struct Metaball { vec3 pos; - /** Radius, density */ - float r, d; + ivec3 coords; + /** Density */ + float d; vec4 col; }; -array metaballs; +array metaballs; +const float cloudScale = metaballR; +const float metaballScale = metaballR * 1.5f; Clouds cs; void calculateMetaballs() { @@ -104,27 +107,36 @@ void calculateMetaballs() { /* 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++) { - 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 < 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]; - metaballs[i * CLOUD_DIM * CLOUD_DIM + j * CLOUD_DIM + k] = m; + /* 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, 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"); @@ -149,9 +161,37 @@ mat4 faceView(mat4 m) { return m; } -GLuint attenuationTex; +#define PBO + +/* const int shadeWidth = 256, shadeHeight = 256; */ +const int shadeWidth = 256, shadeHeight = 256; + +#ifdef PBO +const int numPbos = 512; +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); + + 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 glBlendFunc(GL_ZERO, GL_SRC_ALPHA); @@ -166,14 +206,26 @@ void shadeClouds() { glUniform1i(glGetUniformLocation(bbProg, "tex"), 0); GLuint modelLoc = glGetUniformLocation(bbProg, "model"); + glUniform1i(glGetUniformLocation(bbProg, "debug"), 0); + + 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). @@ -196,41 +248,91 @@ void shadeClouds() { // 1. First get position in opengl screen space: from [-1,1] // 2. Normalize to [0,1] // 3. Multiply by (width * height) - vec2 screenPos = + ivec2 screenPos = ((vec2(proj * view * model * vec4(0, 0, 0, 1)) + vec2(1)) / vec2(2)) * - vec2(width, height); + vec2(shadeWidth, shadeHeight); + +#ifndef PBO vec4 pixel; // TODO: This is a huge bottleneck - glReadPixels(screenPos.x, screenPos.y, 1, 1, GL_RGBA, GL_FLOAT, - value_ptr(pixel)); + 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. k.col = pixel; +#else + + glBindBuffer(GL_PIXEL_PACK_BUFFER, pboBufs[pboIdx]); + // It would be nice if this worked. But it doesn't + // macOS driver does this synchronously + /* glReadPixels(screenPos.x, screenPos.y, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, + */ + /* NULL); */ + glReadPixels(screenPos.x, screenPos.y, 64, 64, 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>(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, "debugContDist"), debugContDist); + 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); @@ -240,10 +342,12 @@ void renderClouds() { 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]. @@ -252,16 +356,25 @@ void renderClouds() { glm::value_ptr(k.col)); // Map the billboard texture. - int dIdx = k.d * NQ; + int dIdx = k.d * (NQ - 1); glBindTexture(GL_TEXTURE_2D, bbTexIds[dIdx]); // Don't modulate it -- blend it glUniform1i(glGetUniformLocation(bbProg, "modulate"), 0); - if (debugContDist) { - glUniform1f(glGetUniformLocation(bbProg, "density"), k.d); - glDisable(GL_BLEND); - model = scale(model, vec3(0.02)); + 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)); } @@ -270,25 +383,34 @@ void renderClouds() { } } -bool needsReshading = true; +bool curBeenShaded = false; + void display() { - if (needsReshading) { + 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(); - needsReshading = false; + 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(); @@ -298,11 +420,10 @@ void display() { bool needsRedisplay = false; void timer(int _) { - /* calculateMetaballs(); */ if (needsRedisplay) { glutPostRedisplay(); - needsRedisplay = false; } + needsRedisplay = false; glutTimerFunc(16, timer, 0); } @@ -310,11 +431,32 @@ void keyboard(unsigned char key, int x, int y) { if (key == ' ') { calculateMetaballs(); needsRedisplay = true; - needsReshading = 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 == 'd') { - debugContDist = !debugContDist; + if (key == 's') { + envColorIdx = (envColorIdx + 1) % envColors.size(); needsRedisplay = true; + curBeenShaded = false; } } @@ -329,7 +471,7 @@ void motion(int x, int y) { float dx = x - prevMouseX, dy = y - prevMouseY; prevMouseX = x; prevMouseY = y; - const vec3 origin(0, 18, 0); + 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}), @@ -344,22 +486,35 @@ void passiveMotion(int x, int y) { 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); @@ -385,14 +540,16 @@ int main(int argc, char **argv) { initClouds(&cs); calculateMetaballs(); - glGenTextures(1, &attenuationTex); - - glutKeyboardFunc(keyboard); - glutMotionFunc(motion); - glutPassiveMotionFunc(passiveMotion); - 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, 64 * 64 * 4, NULL, + GL_DYNAMIC_READ); + } + glBindBuffer(GL_PIXEL_PACK_BUFFER, 0); +#endif glutMainLoop();