diff options
Diffstat (limited to 'deps/raylib/examples/shapes/shapes_top_down_lights.c')
| -rw-r--r-- | deps/raylib/examples/shapes/shapes_top_down_lights.c | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/deps/raylib/examples/shapes/shapes_top_down_lights.c b/deps/raylib/examples/shapes/shapes_top_down_lights.c new file mode 100644 index 0000000..abe845f --- /dev/null +++ b/deps/raylib/examples/shapes/shapes_top_down_lights.c @@ -0,0 +1,356 @@ +/******************************************************************************************* +* +* raylib [shapes] example - top down lights +* +* Example originally created with raylib 4.2, last time updated with raylib 4.2 +* +* Example contributed by Vlad Adrian (@demizdor) 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) 2022-2024 Jeffery Myers (@JeffM2501) +* +********************************************************************************************/ + +#include "raylib.h" +#include "raymath.h" +#include "rlgl.h" + +// Custom Blend Modes +#define RLGL_SRC_ALPHA 0x0302 +#define RLGL_MIN 0x8007 +#define RLGL_MAX 0x8008 + +#define MAX_BOXES 20 +#define MAX_SHADOWS MAX_BOXES*3 // MAX_BOXES *3. Each box can cast up to two shadow volumes for the edges it is away from, and one for the box itself +#define MAX_LIGHTS 16 + +// Shadow geometry type +typedef struct ShadowGeometry { + Vector2 vertices[4]; +} ShadowGeometry; + +// Light info type +typedef struct LightInfo { + bool active; // Is this light slot active? + bool dirty; // Does this light need to be updated? + bool valid; // Is this light in a valid position? + + Vector2 position; // Light position + RenderTexture mask; // Alpha mask for the light + float outerRadius; // The distance the light touches + Rectangle bounds; // A cached rectangle of the light bounds to help with culling + + ShadowGeometry shadows[MAX_SHADOWS]; + int shadowCount; +} LightInfo; + + +LightInfo lights[MAX_LIGHTS] = { 0 }; + +// Move a light and mark it as dirty so that we update it's mask next frame +void MoveLight(int slot, float x, float y) +{ + lights[slot].dirty = true; + lights[slot].position.x = x; + lights[slot].position.y = y; + + // update the cached bounds + lights[slot].bounds.x = x - lights[slot].outerRadius; + lights[slot].bounds.y = y - lights[slot].outerRadius; +} + +// Compute a shadow volume for the edge +// It takes the edge and projects it back by the light radius and turns it into a quad +void ComputeShadowVolumeForEdge(int slot, Vector2 sp, Vector2 ep) +{ + if (lights[slot].shadowCount >= MAX_SHADOWS) return; + + float extension = lights[slot].outerRadius*2; + + Vector2 spVector = Vector2Normalize(Vector2Subtract(sp, lights[slot].position)); + Vector2 spProjection = Vector2Add(sp, Vector2Scale(spVector, extension)); + + Vector2 epVector = Vector2Normalize(Vector2Subtract(ep, lights[slot].position)); + Vector2 epProjection = Vector2Add(ep, Vector2Scale(epVector, extension)); + + lights[slot].shadows[lights[slot].shadowCount].vertices[0] = sp; + lights[slot].shadows[lights[slot].shadowCount].vertices[1] = ep; + lights[slot].shadows[lights[slot].shadowCount].vertices[2] = epProjection; + lights[slot].shadows[lights[slot].shadowCount].vertices[3] = spProjection; + + lights[slot].shadowCount++; +} + +// Draw the light and shadows to the mask for a light +void DrawLightMask(int slot) +{ + // Use the light mask + BeginTextureMode(lights[slot].mask); + + ClearBackground(WHITE); + + // Force the blend mode to only set the alpha of the destination + rlSetBlendFactors(RLGL_SRC_ALPHA, RLGL_SRC_ALPHA, RLGL_MIN); + rlSetBlendMode(BLEND_CUSTOM); + + // If we are valid, then draw the light radius to the alpha mask + if (lights[slot].valid) DrawCircleGradient((int)lights[slot].position.x, (int)lights[slot].position.y, lights[slot].outerRadius, ColorAlpha(WHITE, 0), WHITE); + + rlDrawRenderBatchActive(); + + // Cut out the shadows from the light radius by forcing the alpha to maximum + rlSetBlendMode(BLEND_ALPHA); + rlSetBlendFactors(RLGL_SRC_ALPHA, RLGL_SRC_ALPHA, RLGL_MAX); + rlSetBlendMode(BLEND_CUSTOM); + + // Draw the shadows to the alpha mask + for (int i = 0; i < lights[slot].shadowCount; i++) + { + DrawTriangleFan(lights[slot].shadows[i].vertices, 4, WHITE); + } + + rlDrawRenderBatchActive(); + + // Go back to normal blend mode + rlSetBlendMode(BLEND_ALPHA); + + EndTextureMode(); +} + +// Setup a light +void SetupLight(int slot, float x, float y, float radius) +{ + lights[slot].active = true; + lights[slot].valid = false; // The light must prove it is valid + lights[slot].mask = LoadRenderTexture(GetScreenWidth(), GetScreenHeight()); + lights[slot].outerRadius = radius; + + lights[slot].bounds.width = radius * 2; + lights[slot].bounds.height = radius * 2; + + MoveLight(slot, x, y); + + // Force the render texture to have something in it + DrawLightMask(slot); +} + +// See if a light needs to update it's mask +bool UpdateLight(int slot, Rectangle* boxes, int count) +{ + if (!lights[slot].active || !lights[slot].dirty) return false; + + lights[slot].dirty = false; + lights[slot].shadowCount = 0; + lights[slot].valid = false; + + for (int i = 0; i < count; i++) + { + // Are we in a box? if so we are not valid + if (CheckCollisionPointRec(lights[slot].position, boxes[i])) return false; + + // If this box is outside our bounds, we can skip it + if (!CheckCollisionRecs(lights[slot].bounds, boxes[i])) continue; + + // Check the edges that are on the same side we are, and cast shadow volumes out from them + + // Top + Vector2 sp = (Vector2){ boxes[i].x, boxes[i].y }; + Vector2 ep = (Vector2){ boxes[i].x + boxes[i].width, boxes[i].y }; + + if (lights[slot].position.y > ep.y) ComputeShadowVolumeForEdge(slot, sp, ep); + + // Right + sp = ep; + ep.y += boxes[i].height; + if (lights[slot].position.x < ep.x) ComputeShadowVolumeForEdge(slot, sp, ep); + + // Bottom + sp = ep; + ep.x -= boxes[i].width; + if (lights[slot].position.y < ep.y) ComputeShadowVolumeForEdge(slot, sp, ep); + + // Left + sp = ep; + ep.y -= boxes[i].height; + if (lights[slot].position.x > ep.x) ComputeShadowVolumeForEdge(slot, sp, ep); + + // The box itself + lights[slot].shadows[lights[slot].shadowCount].vertices[0] = (Vector2){ boxes[i].x, boxes[i].y }; + lights[slot].shadows[lights[slot].shadowCount].vertices[1] = (Vector2){ boxes[i].x, boxes[i].y + boxes[i].height }; + lights[slot].shadows[lights[slot].shadowCount].vertices[2] = (Vector2){ boxes[i].x + boxes[i].width, boxes[i].y + boxes[i].height }; + lights[slot].shadows[lights[slot].shadowCount].vertices[3] = (Vector2){ boxes[i].x + boxes[i].width, boxes[i].y }; + lights[slot].shadowCount++; + } + + lights[slot].valid = true; + + DrawLightMask(slot); + + return true; +} + +// Set up some boxes +void SetupBoxes(Rectangle *boxes, int *count) +{ + boxes[0] = (Rectangle){ 150,80, 40, 40 }; + boxes[1] = (Rectangle){ 1200, 700, 40, 40 }; + boxes[2] = (Rectangle){ 200, 600, 40, 40 }; + boxes[3] = (Rectangle){ 1000, 50, 40, 40 }; + boxes[4] = (Rectangle){ 500, 350, 40, 40 }; + + for (int i = 5; i < MAX_BOXES; i++) + { + boxes[i] = (Rectangle){(float)GetRandomValue(0,GetScreenWidth()), (float)GetRandomValue(0,GetScreenHeight()), (float)GetRandomValue(10,100), (float)GetRandomValue(10,100) }; + } + + *count = MAX_BOXES; +} + +//------------------------------------------------------------------------------------ +// Program main entry point +//------------------------------------------------------------------------------------ +int main(void) +{ + // Initialization + //-------------------------------------------------------------------------------------- + const int screenWidth = 800; + const int screenHeight = 450; + + InitWindow(screenWidth, screenHeight, "raylib [shapes] example - top down lights"); + + // Initialize our 'world' of boxes + int boxCount = 0; + Rectangle boxes[MAX_BOXES] = { 0 }; + SetupBoxes(boxes, &boxCount); + + // Create a checkerboard ground texture + Image img = GenImageChecked(64, 64, 32, 32, DARKBROWN, DARKGRAY); + Texture2D backgroundTexture = LoadTextureFromImage(img); + UnloadImage(img); + + // Create a global light mask to hold all the blended lights + RenderTexture lightMask = LoadRenderTexture(GetScreenWidth(), GetScreenHeight()); + + // Setup initial light + SetupLight(0, 600, 400, 300); + int nextLight = 1; + + bool showLines = false; + + SetTargetFPS(60); // Set our game to run at 60 frames-per-second + //-------------------------------------------------------------------------------------- + + // Main game loop + while (!WindowShouldClose()) // Detect window close button or ESC key + { + // Update + //---------------------------------------------------------------------------------- + // Drag light 0 + if (IsMouseButtonDown(MOUSE_BUTTON_LEFT)) MoveLight(0, GetMousePosition().x, GetMousePosition().y); + + // Make a new light + if (IsMouseButtonPressed(MOUSE_BUTTON_RIGHT) && (nextLight < MAX_LIGHTS)) + { + SetupLight(nextLight, GetMousePosition().x, GetMousePosition().y, 200); + nextLight++; + } + + // Toggle debug info + if (IsKeyPressed(KEY_F1)) showLines = !showLines; + + // Update the lights and keep track if any were dirty so we know if we need to update the master light mask + bool dirtyLights = false; + for (int i = 0; i < MAX_LIGHTS; i++) + { + if (UpdateLight(i, boxes, boxCount)) dirtyLights = true; + } + + // Update the light mask + if (dirtyLights) + { + // Build up the light mask + BeginTextureMode(lightMask); + + ClearBackground(BLACK); + + // Force the blend mode to only set the alpha of the destination + rlSetBlendFactors(RLGL_SRC_ALPHA, RLGL_SRC_ALPHA, RLGL_MIN); + rlSetBlendMode(BLEND_CUSTOM); + + // Merge in all the light masks + for (int i = 0; i < MAX_LIGHTS; i++) + { + if (lights[i].active) DrawTextureRec(lights[i].mask.texture, (Rectangle){ 0, 0, (float)GetScreenWidth(), -(float)GetScreenHeight() }, Vector2Zero(), WHITE); + } + + rlDrawRenderBatchActive(); + + // Go back to normal blend + rlSetBlendMode(BLEND_ALPHA); + EndTextureMode(); + } + //---------------------------------------------------------------------------------- + + // Draw + //---------------------------------------------------------------------------------- + BeginDrawing(); + + ClearBackground(BLACK); + + // Draw the tile background + DrawTextureRec(backgroundTexture, (Rectangle){ 0, 0, (float)GetScreenWidth(), (float)GetScreenHeight() }, Vector2Zero(), WHITE); + + // Overlay the shadows from all the lights + DrawTextureRec(lightMask.texture, (Rectangle){ 0, 0, (float)GetScreenWidth(), -(float)GetScreenHeight() }, Vector2Zero(), ColorAlpha(WHITE, showLines? 0.75f : 1.0f)); + + // Draw the lights + for (int i = 0; i < MAX_LIGHTS; i++) + { + if (lights[i].active) DrawCircle((int)lights[i].position.x, (int)lights[i].position.y, 10, (i == 0)? YELLOW : WHITE); + } + + if (showLines) + { + for (int s = 0; s < lights[0].shadowCount; s++) + { + DrawTriangleFan(lights[0].shadows[s].vertices, 4, DARKPURPLE); + } + + for (int b = 0; b < boxCount; b++) + { + if (CheckCollisionRecs(boxes[b],lights[0].bounds)) DrawRectangleRec(boxes[b], PURPLE); + + DrawRectangleLines((int)boxes[b].x, (int)boxes[b].y, (int)boxes[b].width, (int)boxes[b].height, DARKBLUE); + } + + DrawText("(F1) Hide Shadow Volumes", 10, 50, 10, GREEN); + } + else + { + DrawText("(F1) Show Shadow Volumes", 10, 50, 10, GREEN); + } + + DrawFPS(screenWidth - 80, 10); + DrawText("Drag to move light #1", 10, 10, 10, DARKGREEN); + DrawText("Right click to add new light", 10, 30, 10, DARKGREEN); + + EndDrawing(); + //---------------------------------------------------------------------------------- + } + + // De-Initialization + //-------------------------------------------------------------------------------------- + UnloadTexture(backgroundTexture); + UnloadRenderTexture(lightMask); + for (int i = 0; i < MAX_LIGHTS; i++) + { + if (lights[i].active) UnloadRenderTexture(lights[i].mask); + } + + CloseWindow(); // Close window and OpenGL context + //-------------------------------------------------------------------------------------- + + return 0; +}
\ No newline at end of file |