diff --git a/examples/shapes/shapes_rlgl_triangle.c b/examples/shapes/shapes_rlgl_triangle.c new file mode 100644 index 000000000..9174110e4 --- /dev/null +++ b/examples/shapes/shapes_rlgl_triangle.c @@ -0,0 +1,189 @@ +/******************************************************************************************* +* +* raylib [shapes] example - rlgl triangle +* +* Example complexity rating: [★★☆☆] 2/4 +* +* Example originally created with raylib 5.6-dev, last time updated with raylib 5.6-dev +* +* Example contributed by Robin (@RobinsAviary) and reviewed by Ramon Santamaria (@raysan5) +* +* Example licensed under an unmodified zlib/libpng license, which is an OSI-certified, +* BSD-like license that allows static linking with closed source software +* +* Copyright (c) 2025-2025 Robin (@RobinsAviary) +* +********************************************************************************************/ + +#include "raylib.h" +#include "rlgl.h" +#include "raymath.h" + +//------------------------------------------------------------------------------------ +// Program main entry point +//------------------------------------------------------------------------------------ +int main(void) +{ + // Initialization + //-------------------------------------------------------------------------------------- + const int screenWidth = 800; + const int screenHeight = 450; + + SetConfigFlags(FLAG_MSAA_4X_HINT); + InitWindow(screenWidth, screenHeight, "raylib [shapes] example - rlgl triangle"); + + // Starting postions and rendered triangle positions + Vector2 startingPositions[] = {{ 400.0f, 150.0f }, { 300.0f, 300.0f }, { 500.0f, 300.0f }}; + Vector2 trianglePositions[] = { startingPositions[0], startingPositions[1], startingPositions[2] }; + + // Currently selected vertex, -1 means none + int triangleIndex = -1; + + SetTargetFPS(60); + //-------------------------------------------------------------------------------------- + + // Main game loop + while (!WindowShouldClose()) // Detect window close button or ESC key + { + // Update + //---------------------------------------------------------------------------------- + // Reset index on release + if (IsMouseButtonReleased(MOUSE_BUTTON_LEFT)) + { + triangleIndex = -1; + } + + // If the user has selected a vertex, offset it by the mouse's delta this frame + if (triangleIndex != -1) + { + Vector2 *position = &trianglePositions[triangleIndex]; + + Vector2 mouseDelta = GetMouseDelta(); + position->x += mouseDelta.x; + position->y += mouseDelta.y; + } + + // Enable/disable backface culling (2-sided triangles, slower to render) + if (IsKeyPressed(KEY_LEFT)) + { + rlEnableBackfaceCulling(); + } + + if (IsKeyPressed(KEY_RIGHT)) + { + rlDisableBackfaceCulling(); + } + + // Reset triangle vertices to starting positions and reset backface culling + if (IsKeyPressed(KEY_R)) + { + trianglePositions[0] = startingPositions[0]; + trianglePositions[1] = startingPositions[1]; + trianglePositions[2] = startingPositions[2]; + + rlEnableBackfaceCulling(); + } + //---------------------------------------------------------------------------------- + + // Draw + //---------------------------------------------------------------------------------- + BeginDrawing(); + + ClearBackground(RAYWHITE); + + if (IsKeyDown(KEY_SPACE)) + { + // Draw triangle with lines + rlBegin(RL_LINES); + // Three lines, six points + // Define color for next vertex + rlColor4ub(255, 0, 0, 255); + // Define vertex + rlVertex2f(trianglePositions[0].x, trianglePositions[0].y); + rlColor4ub(0, 255, 0, 255); + rlVertex2f(trianglePositions[1].x, trianglePositions[1].y); + + rlColor4ub(0, 255, 0, 255); + rlVertex2f(trianglePositions[1].x, trianglePositions[1].y); + rlColor4ub(0, 0, 255, 255); + rlVertex2f(trianglePositions[2].x, trianglePositions[2].y); + + rlColor4ub(0, 0, 255, 255); + rlVertex2f(trianglePositions[2].x, trianglePositions[2].y); + rlColor4ub(255, 0, 0, 255); + rlVertex2f(trianglePositions[0].x, trianglePositions[0].y); + rlEnd(); + } + else + { + // Draw triangle as a triangle + rlBegin(RL_TRIANGLES); + // One triangle, three points + // Define color for next vertex + rlColor4ub(255, 0, 0, 255); + // Define vertex + rlVertex2f(trianglePositions[0].x, trianglePositions[0].y); + rlColor4ub(0, 255, 0, 255); + rlVertex2f(trianglePositions[1].x, trianglePositions[1].y); + rlColor4ub(0, 0, 255, 255); + rlVertex2f(trianglePositions[2].x, trianglePositions[2].y); + rlEnd(); + } + + // Render the vertex handles, reacting to mouse movement/input + for (unsigned int i = 0; i < 3; i++) + { + Vector2 position = trianglePositions[i]; + + float size = 4.0f; + + Vector2 mousePosition = GetMousePosition(); + + // If the cursor is within the handle circle + if (Vector2Distance(mousePosition, position) < size) + { + float fillAlpha = 0.0f; + if (triangleIndex == -1) + { + fillAlpha = 0.5f; + } + + // If handle selected/clicked + if (i == triangleIndex) + { + fillAlpha = 1.0f; + } + + // If clicked, set selected index to handle index + if (IsMouseButtonPressed(MOUSE_BUTTON_LEFT)) + { + triangleIndex = i; + } + + // If visible, draw DARKGRAY circle with varying alpha. + if (fillAlpha > 0.0f) + { + Color fillColor = ColorAlpha(DARKGRAY, fillAlpha); + + DrawCircleV(position, size, fillColor); + } + } + + // Draw handle outline + DrawCircleLinesV(position, size, BLACK); + } + + // Draw controls + DrawText("space for lines\nleft for backface culling\nright for no backface culling\nclick and drag points\nr to reset", 10, 10, 20, DARKGRAY); + + EndDrawing(); + //---------------------------------------------------------------------------------- + } + + // De-Initialization + //-------------------------------------------------------------------------------------- + CloseWindow(); // Close window and OpenGL context + //-------------------------------------------------------------------------------------- + + return 0; +} \ No newline at end of file diff --git a/examples/shapes/shapes_rlgl_triangle.png b/examples/shapes/shapes_rlgl_triangle.png new file mode 100644 index 000000000..9fec558ff Binary files /dev/null and b/examples/shapes/shapes_rlgl_triangle.png differ