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@ -20,14 +20,17 @@ |
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#include "rlgl.h" |
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// Custom Blend Modes |
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#define RLGL_SRC_ALPHA 0x0302 |
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#define RLGL_MIN 0x8007 |
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#define RLGL_MAX 0x8008 |
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#define RLGL_SRC_ALPHA 0x0302 |
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#define RLGL_MIN 0x8007 |
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#define RLGL_MAX 0x8008 |
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#define MAX_BOXES 20 |
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#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 |
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#define MAX_LIGHTS 16 |
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#define MAX_BOXES 20 |
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#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 |
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#define MAX_LIGHTS 16 |
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//---------------------------------------------------------------------------------- |
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// Types and Structures Definition |
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//---------------------------------------------------------------------------------- |
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// Shadow geometry type |
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typedef struct ShadowGeometry { |
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Vector2 vertices[4]; |
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@ -48,167 +51,26 @@ typedef struct LightInfo { |
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int shadowCount; |
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} LightInfo; |
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//------------------------------------------------------------------------------------ |
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// Global Variables Definition |
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//------------------------------------------------------------------------------------ |
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static LightInfo lights[MAX_LIGHTS] = { 0 }; |
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LightInfo lights[MAX_LIGHTS] = { 0 }; |
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//------------------------------------------------------------------------------------ |
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// Module Functions Declaration |
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//------------------------------------------------------------------------------------ |
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// Move a light and mark it as dirty so that we update it's mask next frame |
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void MoveLight(int slot, float x, float y) |
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{ |
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lights[slot].dirty = true; |
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lights[slot].position.x = x; |
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lights[slot].position.y = y; |
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// update the cached bounds |
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lights[slot].bounds.x = x - lights[slot].outerRadius; |
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lights[slot].bounds.y = y - lights[slot].outerRadius; |
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} |
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static void MoveLight(int slot, float x, float y); |
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// Compute a shadow volume for the edge |
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// It takes the edge and projects it back by the light radius and turns it into a quad |
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void ComputeShadowVolumeForEdge(int slot, Vector2 sp, Vector2 ep) |
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{ |
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if (lights[slot].shadowCount >= MAX_SHADOWS) return; |
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float extension = lights[slot].outerRadius*2; |
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Vector2 spVector = Vector2Normalize(Vector2Subtract(sp, lights[slot].position)); |
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Vector2 spProjection = Vector2Add(sp, Vector2Scale(spVector, extension)); |
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Vector2 epVector = Vector2Normalize(Vector2Subtract(ep, lights[slot].position)); |
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Vector2 epProjection = Vector2Add(ep, Vector2Scale(epVector, extension)); |
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lights[slot].shadows[lights[slot].shadowCount].vertices[0] = sp; |
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lights[slot].shadows[lights[slot].shadowCount].vertices[1] = ep; |
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lights[slot].shadows[lights[slot].shadowCount].vertices[2] = epProjection; |
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lights[slot].shadows[lights[slot].shadowCount].vertices[3] = spProjection; |
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lights[slot].shadowCount++; |
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} |
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static void ComputeShadowVolumeForEdge(int slot, Vector2 sp, Vector2 ep); |
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// Draw the light and shadows to the mask for a light |
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void DrawLightMask(int slot) |
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{ |
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// Use the light mask |
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BeginTextureMode(lights[slot].mask); |
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ClearBackground(WHITE); |
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// Force the blend mode to only set the alpha of the destination |
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rlSetBlendFactors(RLGL_SRC_ALPHA, RLGL_SRC_ALPHA, RLGL_MIN); |
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rlSetBlendMode(BLEND_CUSTOM); |
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// If we are valid, then draw the light radius to the alpha mask |
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if (lights[slot].valid) DrawCircleGradient((int)lights[slot].position.x, (int)lights[slot].position.y, lights[slot].outerRadius, ColorAlpha(WHITE, 0), WHITE); |
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rlDrawRenderBatchActive(); |
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// Cut out the shadows from the light radius by forcing the alpha to maximum |
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rlSetBlendMode(BLEND_ALPHA); |
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rlSetBlendFactors(RLGL_SRC_ALPHA, RLGL_SRC_ALPHA, RLGL_MAX); |
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rlSetBlendMode(BLEND_CUSTOM); |
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// Draw the shadows to the alpha mask |
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for (int i = 0; i < lights[slot].shadowCount; i++) |
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{ |
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DrawTriangleFan(lights[slot].shadows[i].vertices, 4, WHITE); |
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} |
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rlDrawRenderBatchActive(); |
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// Go back to normal blend mode |
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rlSetBlendMode(BLEND_ALPHA); |
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EndTextureMode(); |
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} |
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static void DrawLightMask(int slot); |
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// Setup a light |
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void SetupLight(int slot, float x, float y, float radius) |
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{ |
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lights[slot].active = true; |
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lights[slot].valid = false; // The light must prove it is valid |
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lights[slot].mask = LoadRenderTexture(GetScreenWidth(), GetScreenHeight()); |
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lights[slot].outerRadius = radius; |
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lights[slot].bounds.width = radius*2; |
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lights[slot].bounds.height = radius*2; |
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MoveLight(slot, x, y); |
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// Force the render texture to have something in it |
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DrawLightMask(slot); |
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} |
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static void SetupLight(int slot, float x, float y, float radius); |
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// See if a light needs to update it's mask |
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bool UpdateLight(int slot, Rectangle* boxes, int count) |
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{ |
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if (!lights[slot].active || !lights[slot].dirty) return false; |
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lights[slot].dirty = false; |
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lights[slot].shadowCount = 0; |
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lights[slot].valid = false; |
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for (int i = 0; i < count; i++) |
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{ |
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// Are we in a box? if so we are not valid |
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if (CheckCollisionPointRec(lights[slot].position, boxes[i])) return false; |
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// If this box is outside our bounds, we can skip it |
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if (!CheckCollisionRecs(lights[slot].bounds, boxes[i])) continue; |
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// Check the edges that are on the same side we are, and cast shadow volumes out from them |
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// Top |
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Vector2 sp = (Vector2){ boxes[i].x, boxes[i].y }; |
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Vector2 ep = (Vector2){ boxes[i].x + boxes[i].width, boxes[i].y }; |
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if (lights[slot].position.y > ep.y) ComputeShadowVolumeForEdge(slot, sp, ep); |
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// Right |
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sp = ep; |
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ep.y += boxes[i].height; |
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if (lights[slot].position.x < ep.x) ComputeShadowVolumeForEdge(slot, sp, ep); |
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// Bottom |
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sp = ep; |
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ep.x -= boxes[i].width; |
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if (lights[slot].position.y < ep.y) ComputeShadowVolumeForEdge(slot, sp, ep); |
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// Left |
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sp = ep; |
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ep.y -= boxes[i].height; |
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if (lights[slot].position.x > ep.x) ComputeShadowVolumeForEdge(slot, sp, ep); |
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// The box itself |
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lights[slot].shadows[lights[slot].shadowCount].vertices[0] = (Vector2){ boxes[i].x, boxes[i].y }; |
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lights[slot].shadows[lights[slot].shadowCount].vertices[1] = (Vector2){ boxes[i].x, boxes[i].y + boxes[i].height }; |
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lights[slot].shadows[lights[slot].shadowCount].vertices[2] = (Vector2){ boxes[i].x + boxes[i].width, boxes[i].y + boxes[i].height }; |
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lights[slot].shadows[lights[slot].shadowCount].vertices[3] = (Vector2){ boxes[i].x + boxes[i].width, boxes[i].y }; |
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lights[slot].shadowCount++; |
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} |
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lights[slot].valid = true; |
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DrawLightMask(slot); |
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return true; |
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} |
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static bool UpdateLight(int slot, Rectangle* boxes, int count); |
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// Set up some boxes |
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void SetupBoxes(Rectangle *boxes, int *count) |
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{ |
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boxes[0] = (Rectangle){ 150,80, 40, 40 }; |
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boxes[1] = (Rectangle){ 1200, 700, 40, 40 }; |
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boxes[2] = (Rectangle){ 200, 600, 40, 40 }; |
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boxes[3] = (Rectangle){ 1000, 50, 40, 40 }; |
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boxes[4] = (Rectangle){ 500, 350, 40, 40 }; |
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for (int i = 5; i < MAX_BOXES; i++) |
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{ |
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boxes[i] = (Rectangle){(float)GetRandomValue(0,GetScreenWidth()), (float)GetRandomValue(0,GetScreenHeight()), (float)GetRandomValue(10,100), (float)GetRandomValue(10,100) }; |
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} |
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*count = MAX_BOXES; |
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} |
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static void SetupBoxes(Rectangle *boxes, int *count); |
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//------------------------------------------------------------------------------------ |
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// Program main entry point |
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@ -356,3 +218,165 @@ int main(void) |
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return 0; |
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} |
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//------------------------------------------------------------------------------------ |
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// Module Functions Definition |
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//------------------------------------------------------------------------------------ |
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// Move a light and mark it as dirty so that we update it's mask next frame |
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static void MoveLight(int slot, float x, float y) |
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{ |
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lights[slot].dirty = true; |
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lights[slot].position.x = x; |
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lights[slot].position.y = y; |
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// update the cached bounds |
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lights[slot].bounds.x = x - lights[slot].outerRadius; |
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lights[slot].bounds.y = y - lights[slot].outerRadius; |
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} |
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// Compute a shadow volume for the edge |
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// It takes the edge and projects it back by the light radius and turns it into a quad |
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static void ComputeShadowVolumeForEdge(int slot, Vector2 sp, Vector2 ep) |
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{ |
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if (lights[slot].shadowCount >= MAX_SHADOWS) return; |
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float extension = lights[slot].outerRadius*2; |
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Vector2 spVector = Vector2Normalize(Vector2Subtract(sp, lights[slot].position)); |
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Vector2 spProjection = Vector2Add(sp, Vector2Scale(spVector, extension)); |
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Vector2 epVector = Vector2Normalize(Vector2Subtract(ep, lights[slot].position)); |
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Vector2 epProjection = Vector2Add(ep, Vector2Scale(epVector, extension)); |
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lights[slot].shadows[lights[slot].shadowCount].vertices[0] = sp; |
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lights[slot].shadows[lights[slot].shadowCount].vertices[1] = ep; |
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lights[slot].shadows[lights[slot].shadowCount].vertices[2] = epProjection; |
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lights[slot].shadows[lights[slot].shadowCount].vertices[3] = spProjection; |
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lights[slot].shadowCount++; |
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} |
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// Setup a light |
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static void SetupLight(int slot, float x, float y, float radius) |
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{ |
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lights[slot].active = true; |
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lights[slot].valid = false; // The light must prove it is valid |
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lights[slot].mask = LoadRenderTexture(GetScreenWidth(), GetScreenHeight()); |
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lights[slot].outerRadius = radius; |
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lights[slot].bounds.width = radius*2; |
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lights[slot].bounds.height = radius*2; |
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MoveLight(slot, x, y); |
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// Force the render texture to have something in it |
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DrawLightMask(slot); |
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} |
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// See if a light needs to update it's mask |
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static bool UpdateLight(int slot, Rectangle* boxes, int count) |
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{ |
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if (!lights[slot].active || !lights[slot].dirty) return false; |
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lights[slot].dirty = false; |
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lights[slot].shadowCount = 0; |
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lights[slot].valid = false; |
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for (int i = 0; i < count; i++) |
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{ |
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// Are we in a box? if so we are not valid |
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if (CheckCollisionPointRec(lights[slot].position, boxes[i])) return false; |
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// If this box is outside our bounds, we can skip it |
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if (!CheckCollisionRecs(lights[slot].bounds, boxes[i])) continue; |
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// Check the edges that are on the same side we are, and cast shadow volumes out from them |
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// Top |
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Vector2 sp = (Vector2){ boxes[i].x, boxes[i].y }; |
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Vector2 ep = (Vector2){ boxes[i].x + boxes[i].width, boxes[i].y }; |
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if (lights[slot].position.y > ep.y) ComputeShadowVolumeForEdge(slot, sp, ep); |
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// Right |
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sp = ep; |
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ep.y += boxes[i].height; |
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if (lights[slot].position.x < ep.x) ComputeShadowVolumeForEdge(slot, sp, ep); |
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// Bottom |
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sp = ep; |
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ep.x -= boxes[i].width; |
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if (lights[slot].position.y < ep.y) ComputeShadowVolumeForEdge(slot, sp, ep); |
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// Left |
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sp = ep; |
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ep.y -= boxes[i].height; |
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if (lights[slot].position.x > ep.x) ComputeShadowVolumeForEdge(slot, sp, ep); |
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// The box itself |
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lights[slot].shadows[lights[slot].shadowCount].vertices[0] = (Vector2){ boxes[i].x, boxes[i].y }; |
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lights[slot].shadows[lights[slot].shadowCount].vertices[1] = (Vector2){ boxes[i].x, boxes[i].y + boxes[i].height }; |
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lights[slot].shadows[lights[slot].shadowCount].vertices[2] = (Vector2){ boxes[i].x + boxes[i].width, boxes[i].y + boxes[i].height }; |
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lights[slot].shadows[lights[slot].shadowCount].vertices[3] = (Vector2){ boxes[i].x + boxes[i].width, boxes[i].y }; |
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lights[slot].shadowCount++; |
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} |
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lights[slot].valid = true; |
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DrawLightMask(slot); |
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return true; |
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} |
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// Draw the light and shadows to the mask for a light |
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static void DrawLightMask(int slot) |
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{ |
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// Use the light mask |
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BeginTextureMode(lights[slot].mask); |
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ClearBackground(WHITE); |
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// Force the blend mode to only set the alpha of the destination |
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rlSetBlendFactors(RLGL_SRC_ALPHA, RLGL_SRC_ALPHA, RLGL_MIN); |
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rlSetBlendMode(BLEND_CUSTOM); |
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// If we are valid, then draw the light radius to the alpha mask |
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if (lights[slot].valid) DrawCircleGradient((int)lights[slot].position.x, (int)lights[slot].position.y, lights[slot].outerRadius, ColorAlpha(WHITE, 0), WHITE); |
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rlDrawRenderBatchActive(); |
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// Cut out the shadows from the light radius by forcing the alpha to maximum |
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rlSetBlendMode(BLEND_ALPHA); |
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rlSetBlendFactors(RLGL_SRC_ALPHA, RLGL_SRC_ALPHA, RLGL_MAX); |
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rlSetBlendMode(BLEND_CUSTOM); |
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// Draw the shadows to the alpha mask |
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for (int i = 0; i < lights[slot].shadowCount; i++) |
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{ |
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DrawTriangleFan(lights[slot].shadows[i].vertices, 4, WHITE); |
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} |
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rlDrawRenderBatchActive(); |
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// Go back to normal blend mode |
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rlSetBlendMode(BLEND_ALPHA); |
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EndTextureMode(); |
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} |
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// Set up some boxes |
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static void SetupBoxes(Rectangle *boxes, int *count) |
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{ |
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boxes[0] = (Rectangle){ 150,80, 40, 40 }; |
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boxes[1] = (Rectangle){ 1200, 700, 40, 40 }; |
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boxes[2] = (Rectangle){ 200, 600, 40, 40 }; |
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boxes[3] = (Rectangle){ 1000, 50, 40, 40 }; |
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boxes[4] = (Rectangle){ 500, 350, 40, 40 }; |
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for (int i = 5; i < MAX_BOXES; i++) |
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{ |
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boxes[i] = (Rectangle){(float)GetRandomValue(0,GetScreenWidth()), (float)GetRandomValue(0,GetScreenHeight()), (float)GetRandomValue(10,100), (float)GetRandomValue(10,100) }; |
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} |
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*count = MAX_BOXES; |
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} |