136 lines
4.5 KiB
C
136 lines
4.5 KiB
C
#include "raylib.h"
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#include <stdlib.h>
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#include <stdio.h>
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#include <math.h>
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#define MAX_POINTS 10000000
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#define MIN_POINTS 1000
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float randFloat()
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{
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return (float)rand() / RAND_MAX;
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}
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static Mesh GenMeshCustom(int numPoints)
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{
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Mesh mesh = {
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.triangleCount = 1,
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.vertexCount = numPoints,
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.vertices = (float *)MemAlloc(numPoints * 3 * sizeof(float)),
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.colors = (unsigned char*)MemAlloc(numPoints * 4 * sizeof(unsigned char)),
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};
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// https://en.wikipedia.org/wiki/Spherical_coordinate_system
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for (int i = 0; i < numPoints; i++) {
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float theta = PI * randFloat();
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float phi = 2 * PI * randFloat();
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float r = 10.0f * randFloat();
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mesh.vertices[i * 3 + 0] = r * sin(theta) * cos(phi);
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mesh.vertices[i * 3 + 1] = r * sin(theta) * sin(phi);
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mesh.vertices[i * 3 + 2] = r * cos(theta);
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Color color = ColorFromHSV(r * 360.0f, 1.0f, 1.0f);
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mesh.colors[i * 4 + 0] = color.r;
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mesh.colors[i * 4 + 1] = color.g;
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mesh.colors[i * 4 + 2] = color.b;
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mesh.colors[i * 4 + 3] = color.a;
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}
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// Upload mesh data from CPU (RAM) to GPU (VRAM) memory
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UploadMesh(&mesh, false);
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return mesh;
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}
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int main()
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{
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Camera camera = {
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.position = {3.0f, 3.0f, 3.0f},
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.target = {0.0f, 0.0f, 0.0f},
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.up = {0.0f, 1.0f, 0.0f},
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.fovy = 45.0f,
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.projection = CAMERA_PERSPECTIVE,
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};
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InitWindow(800, 600, "Point Rendering");
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Vector3 position = {0.0f, 0.0f, 0.0f};
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bool newMethod = true;
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bool numPointsChanged = false;
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int numPoints = 1000;
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Mesh mesh = GenMeshCustom(numPoints);
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Model model = LoadModelFromMesh(mesh);
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SetTargetFPS(60);
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while(!WindowShouldClose()) {
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UpdateCamera(&camera, CAMERA_ORBITAL);
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if (IsKeyPressed(KEY_SPACE)) newMethod = !newMethod;
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if (IsKeyPressed(KEY_UP)) {
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numPoints = (numPoints * 10 > MAX_POINTS) ? MAX_POINTS : numPoints * 10;
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numPointsChanged = true;
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TraceLog(LOG_INFO, "num points %d", numPoints);
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}
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if (IsKeyPressed(KEY_DOWN)) {
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numPoints = (numPoints / 10 < MIN_POINTS) ? MIN_POINTS : numPoints / 10;
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numPointsChanged = true;
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TraceLog(LOG_INFO, "num points %d", numPoints);
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}
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/* re-upload a different point cloud size */
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if (numPointsChanged) {
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UnloadModel(model);
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mesh = GenMeshCustom(numPoints);
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model = LoadModelFromMesh(mesh);
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numPointsChanged = false;
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}
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BeginDrawing();
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ClearBackground(BLACK);
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BeginMode3D(camera);
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/* The new method only uploads the points once to the GPU */
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if (newMethod) {
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DrawModelPoints(model, position, 1.0f, WHITE);
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} else {
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/* The old method must continually draw the "points" (lines) */
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for (int i = 0; i < numPoints; i++) {
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Vector3 pos = {
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.x = mesh.vertices[i * 3 + 0],
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.y = mesh.vertices[i * 3 + 1],
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.z = mesh.vertices[i * 3 + 2],
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};
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Color color = {
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.r = mesh.colors[i * 4 + 0],
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.g = mesh.colors[i * 4 + 1],
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.b = mesh.colors[i * 4 + 2],
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.a = mesh.colors[i * 4 + 3],
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};
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DrawPoint3D(pos, color);
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}
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}
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DrawSphereWires(position, 1.0f, 10, 10, YELLOW);
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EndMode3D();
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/* Text formatting */
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Color color = WHITE;
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int fps = GetFPS();
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if ((fps < 30) && (fps >= 15)) color = ORANGE;
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else if (fps < 15) color = RED;
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DrawText(TextFormat("%2i FPS", fps), 20, 20, 40, color);
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DrawText(TextFormat("Point Count %d", numPoints), 20, 550, 40, WHITE);
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DrawText("Up - increase points", 20, 70, 20, WHITE);
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DrawText("Down - decrease points", 20, 100, 20, WHITE);
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DrawText("Space - draw mode", 20, 130, 20, WHITE);
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if (newMethod) {
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DrawText("DrawModelPoints", 20, 160, 20, GREEN);
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} else {
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DrawText("DrawPoint3D", 20, 160, 20, RED);
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}
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EndDrawing();
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}
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UnloadModel(model);
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CloseWindow();
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return 0;
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}
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