sdf-2d/src/graphics/rendering/shaders/shading-fs.glsl
schmelczerandras 374796f398 Fix flashlights
2020-10-02 11:23:10 +02:00

145 lines
4.5 KiB
GLSL

#version 300 es
precision lowp float;
#define INTENSITY_INSIDE_RATIO 0.5
#define SHADOW_TRACE_COUNT {shadowTraceCount}
{macroDefinitions}
uniform float shadingNdcPixelSize;
uniform vec2 squareToAspectRatioTimes2;
uniform vec3 ambientLight;
uniform vec4 backgroundColor;
uniform sampler2D distanceTexture;
uniform sampler2D palette;
in vec2 position;
in vec2 uvCoordinates;
float getDistance(in vec2 target, out vec4 color) {
vec4 values = texture(distanceTexture, target);
color = texture(palette, vec2(values[1], 0.0));
return values[0];
}
float getDistance(in vec2 target) {
return texture(distanceTexture, target)[0];
}
float shadowTransparency(float startingDistance, float lightCenterDistance, vec2 direction) {
float rayLength = startingDistance;
for (int j = 0; j < SHADOW_TRACE_COUNT; j++) {
rayLength += max(0.0, getDistance(uvCoordinates + direction * rayLength));
}
return min(1.0, pow(rayLength / lightCenterDistance, 0.3));
}
#ifdef CIRCLE_LIGHT_COUNT
#if CIRCLE_LIGHT_COUNT > 0
uniform vec2 circleLightCenters[CIRCLE_LIGHT_COUNT];
uniform float circleLightIntensities[CIRCLE_LIGHT_COUNT];
uniform vec3 circleLightColors[CIRCLE_LIGHT_COUNT];
in vec2 circleLightDirections[CIRCLE_LIGHT_COUNT];
vec3 colorInPosition(int lightIndex, out float lightCenterDistance) {
lightCenterDistance = distance(circleLightCenters[lightIndex], position);
return circleLightColors[lightIndex] / pow(
lightCenterDistance / circleLightIntensities[lightIndex] + 1.0, 2.0
);
}
#endif
#endif
#ifdef FLASHLIGHT_COUNT
#if FLASHLIGHT_COUNT > 0
uniform vec2 flashlightCenters[FLASHLIGHT_COUNT];
uniform float flashlightIntensities[FLASHLIGHT_COUNT];
uniform vec3 flashlightColors[FLASHLIGHT_COUNT];
uniform vec2 flashlightDirections[FLASHLIGHT_COUNT];
in vec2 flashlightActualDirections[FLASHLIGHT_COUNT];
float intensityInDirection(vec2 lightDirection, vec2 targetDirection) {
return smoothstep(
0.0,
1.0,
10.0 * max(0.0, dot(targetDirection, -lightDirection) - 0.9)
);
}
vec3 colorInPosition(int lightIndex, vec2 positionDirection, out float lightCenterDistance) {
lightCenterDistance = distance(flashlightCenters[lightIndex], position);
return intensityInDirection(flashlightDirections[lightIndex], positionDirection) *
flashlightColors[lightIndex] / pow(
lightCenterDistance / flashlightIntensities[lightIndex] + 1.0, 2.0
);
}
#endif
#endif
out vec4 fragmentColor;
void main() {
vec4 rgbaColorAtPosition;
float startingDistance = getDistance(uvCoordinates, rgbaColorAtPosition);
vec3 colorAtPosition = rgbaColorAtPosition.rgb;
vec3 lighting = ambientLight;
vec3 lightingInside = lighting;
#ifdef CIRCLE_LIGHT_COUNT
#if CIRCLE_LIGHT_COUNT > 0
for (int i = 0; i < CIRCLE_LIGHT_COUNT; i++) {
float lightCenterDistance;
vec3 lightColorAtPosition = colorInPosition(i, lightCenterDistance);
vec2 direction = normalize(circleLightDirections[i]) / squareToAspectRatioTimes2;
lighting += lightColorAtPosition * shadowTransparency(
startingDistance,
lightCenterDistance,
direction
);
lightingInside += lightColorAtPosition;
}
#endif
#endif
#ifdef FLASHLIGHT_COUNT
#if FLASHLIGHT_COUNT > 0
for (int i = 0; i < FLASHLIGHT_COUNT; i++) {
vec2 originalDirection = normalize(flashlightActualDirections[i]);
float lightCenterDistance;
vec3 lightColorAtPosition = colorInPosition(i, originalDirection, lightCenterDistance);
vec2 direction = originalDirection / squareToAspectRatioTimes2;
if (length(lightColorAtPosition) < 0.0) {
continue;
}
lighting += lightColorAtPosition * shadowTransparency(
startingDistance,
lightCenterDistance,
direction
);
lightingInside += lightColorAtPosition;
}
#endif
#endif
vec3 outsideColor = backgroundColor.rgb * lighting;
vec3 insideColor = colorAtPosition * lightingInside * INTENSITY_INSIDE_RATIO;
float edge = clamp(startingDistance / shadingNdcPixelSize, 0.0, 1.0);
vec3 antialiasedColor = mix(insideColor, outsideColor, edge);
fragmentColor = vec4(
antialiasedColor,
mix(rgbaColorAtPosition.a, backgroundColor.a, step(0.0, startingDistance))
);
}