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Fixes to handle shadows on edges that are near to the light better.

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This commit is contained in:
Jeffery Myers 2021-12-07 16:32:13 -08:00
parent e5ce5ef05e
commit a5d33a6116
1 changed files with 17 additions and 11 deletions
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28
examples/effects/top_down_lights.c
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@ -35,7 +35,7 @@ typedef struct
Vector2 Vertecies[4];
}ShadowGeometry;
#define MAX_SHADOWS MAX_BOXES*2 // MAX_BOXES * 2. Each box can cast up to two shadow volumes for the edges
#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
typedef struct
{
@ -79,7 +79,6 @@ void MoveLight(int slot, float x, float y)
Lights[slot].Bounds.y = y - Lights[slot].OuterRadius;
}
// compute a shadow volume for the edge
// 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)
@ -87,7 +86,7 @@ void ComputeShadowVolumeForEdge(int slot, Vector2 sp, Vector2 ep)
if (Lights[slot].ShadowCount >= MAX_SHADOWS)
return;
float extension = Lights[slot].OuterRadius;
float extension = Lights[slot].OuterRadius*2;
Vector2 spVector = Vector2Normalize(Vector2Subtract(sp, Lights[slot].Position));
Vector2 spProjection = Vector2Add(sp, Vector2Scale(spVector, extension));
@ -96,9 +95,9 @@ void ComputeShadowVolumeForEdge(int slot, Vector2 sp, Vector2 ep)
Vector2 epProjection = Vector2Add(ep, Vector2Scale(epVector, extension));
Lights[slot].Shadows[Lights[slot].ShadowCount].Vertecies[0] = sp;
Lights[slot].Shadows[Lights[slot].ShadowCount].Vertecies[1] = spProjection;
Lights[slot].Shadows[Lights[slot].ShadowCount].Vertecies[2] = epProjection;
Lights[slot].Shadows[Lights[slot].ShadowCount].Vertecies[3] = ep;
Lights[slot].Shadows[Lights[slot].ShadowCount].Vertecies[1] = ep;
Lights[slot].Shadows[Lights[slot].ShadowCount].Vertecies[2] = epProjection;
Lights[slot].Shadows[Lights[slot].ShadowCount].Vertecies[3] = spProjection;
Lights[slot].ShadowCount++;
}
@ -120,7 +119,7 @@ void UpdateLightMask(int slot)
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 raidus by forcing the alpha to maxium
// 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);
@ -181,26 +180,33 @@ bool UpdateLight(int slot, Rectangle* boxes, int count)
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)
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)
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)
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)
if (Lights[slot].Position.x > ep.x)
ComputeShadowVolumeForEdge(slot, sp, ep);
// the box itself
Lights[slot].Shadows[Lights[slot].ShadowCount].Vertecies[0] = (Vector2){ boxes[i].x, boxes[i].y };
Lights[slot].Shadows[Lights[slot].ShadowCount].Vertecies[1] = (Vector2){ boxes[i].x, boxes[i].y + boxes[i].height };
Lights[slot].Shadows[Lights[slot].ShadowCount].Vertecies[2] = (Vector2){ boxes[i].x + boxes[i].width, boxes[i].y + boxes[i].height };
Lights[slot].Shadows[Lights[slot].ShadowCount].Vertecies[3] = (Vector2){ boxes[i].x + boxes[i].width, boxes[i].y };
Lights[slot].ShadowCount++;
}
Lights[slot].Valid = true;