You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
382 lines
14 KiB
382 lines
14 KiB
/*******************************************************************************************
|
|
*
|
|
* raylib [shapes] example - top down lights
|
|
*
|
|
* Example complexity rating: [★★★★] 4/4
|
|
*
|
|
* Example originally created with raylib 4.2, last time updated with raylib 4.2
|
|
*
|
|
* Example contributed by Jeffery Myers (@JeffM2501) 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) 2022-2025 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
|
|
|
|
//----------------------------------------------------------------------------------
|
|
// Types and Structures Definition
|
|
//----------------------------------------------------------------------------------
|
|
// 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;
|
|
|
|
//------------------------------------------------------------------------------------
|
|
// Global Variables Definition
|
|
//------------------------------------------------------------------------------------
|
|
static LightInfo lights[MAX_LIGHTS] = { 0 };
|
|
|
|
//------------------------------------------------------------------------------------
|
|
// Module Functions Declaration
|
|
//------------------------------------------------------------------------------------
|
|
// Move a light and mark it as dirty so that we update it's mask next frame
|
|
static void MoveLight(int slot, float x, float y);
|
|
// Compute a shadow volume for the edge
|
|
static void ComputeShadowVolumeForEdge(int slot, Vector2 sp, Vector2 ep);
|
|
// Draw the light and shadows to the mask for a light
|
|
static void DrawLightMask(int slot);
|
|
// Setup a light
|
|
static void SetupLight(int slot, float x, float y, float radius);
|
|
// See if a light needs to update it's mask
|
|
static bool UpdateLight(int slot, Rectangle* boxes, int count);
|
|
// Set up some boxes
|
|
static void SetupBoxes(Rectangle *boxes, int *count);
|
|
|
|
//------------------------------------------------------------------------------------
|
|
// 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;
|
|
}
|
|
|
|
//------------------------------------------------------------------------------------
|
|
// Module Functions Definition
|
|
//------------------------------------------------------------------------------------
|
|
// Move a light and mark it as dirty so that we update it's mask next frame
|
|
static 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
|
|
static 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++;
|
|
}
|
|
|
|
// Setup a light
|
|
static 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
|
|
static 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;
|
|
}
|
|
|
|
// Draw the light and shadows to the mask for a light
|
|
static 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();
|
|
}
|
|
|
|
// Set up some boxes
|
|
static 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;
|
|
}
|