From 2dbcef218ca5ddf4fa0c7857ac80947af0da16d5 Mon Sep 17 00:00:00 2001
From: chriscamacho <chriscamacho@users.noreply.github.com>
Date: Wed, 25 Mar 2020 09:28:16 +0000
Subject: [PATCH] spotlight example, each spot has own radius, mouse countrol
(#1148)
NB glsl100 shader needs testing on "bare metal"
Co-authored-by: codifies <nospam@antispam.com>
---
.../resources/shaders/glsl100/spotlight.fs | 63 ++++++++-----
.../resources/shaders/glsl330/spotlight.fs | 51 +++++++---
examples/shaders/shaders_spotlight.c | 92 ++++++++++++++-----
3 files changed, 148 insertions(+), 58 deletions(-)
diff --git a/examples/shaders/resources/shaders/glsl100/spotlight.fs b/examples/shaders/resources/shaders/glsl100/spotlight.fs
index 204b89a72..65612753f 100644
--- a/examples/shaders/resources/shaders/glsl100/spotlight.fs
+++ b/examples/shaders/resources/shaders/glsl100/spotlight.fs
@@ -2,50 +2,67 @@
precision mediump float;
-#define MAX_SPOTS 4
-#define RADIUS 256.0
-#define INNER 200.0
+#define MAX_SPOTS 3
-// Inputs
-// array of spotlight positions
-uniform vec2 spots[MAX_SPOTS];
-uniform float screenWidth; // width of the screen
+struct Spot {
+ vec2 pos; // window coords of spot
+ float inner; // inner fully transparent centre radius
+ float radius; // alpha fades out to this radius
+};
+
+uniform Spot spots[MAX_SPOTS]; // Spotlight positions array
+uniform float screenWidth; // Width of the screen
void main()
{
- float alpha;
+ float alpha = 1.0;
// get the position of the current fragment (screen coordinates!)
vec2 pos = vec2(gl_FragCoord.x, gl_FragCoord.y);
// find out which spotlight is nearest
float d = 65000.0; // some high value
- float di = 0.0;
+ int fi = -1;
for (int i = 0; i < MAX_SPOTS; i++)
{
- di = distance(pos, spots[i]);
- if (d > di) d = di;
+ for (int j = 0; j < MAX_SPOTS; j++)
+ {
+ float dj = distance(pos, spots[j].pos) - spots[j].radius + spots[i].radius;
+ if (d > dj )
+ {
+ d = dj;
+ fi = i;
+ }
+ }
}
// d now equals distance to nearest spot...
- if (d > RADIUS) {
- alpha = 1.0;
- } else {
- if (d < INNER) {
- alpha = 0.0;
- } else {
- alpha = (d - INNER) / (RADIUS - INNER);
+ // allowing for the different radii of all spotlights
+ if (fi != -1) {
+
+ if (d > spots[fi].radius)
+ {
+ alpha = 1.0;
+ }
+ else
+ {
+ if (d < spots[fi].inner)
+ {
+ alpha = 0.0;
+ }
+ else
+ {
+ alpha = (d - spots[fi].inner) / (spots[fi].radius - spots[fi].inner);
+ }
}
}
- // right hand side of screen is dimly lit, could make the
- // threshold value user definable.
- if (pos.x > screenWidth/2.0 && alpha > 0.9) {
- alpha = 0.9;
- }
+ // Right hand side of screen is dimly lit,
+ // could make the threshold value user definable
+ if ((pos.x > screenWidth/2.0) && (alpha > 0.9)) alpha = 0.9;
// could make the black out colour user definable...
gl_FragColor = vec4( 0, 0, 0, alpha);
diff --git a/examples/shaders/resources/shaders/glsl330/spotlight.fs b/examples/shaders/resources/shaders/glsl330/spotlight.fs
index f20d92a80..fe53ad61f 100644
--- a/examples/shaders/resources/shaders/glsl330/spotlight.fs
+++ b/examples/shaders/resources/shaders/glsl330/spotlight.fs
@@ -9,36 +9,61 @@ out vec4 finalColor;
// NOTE: Add here your custom variables
-#define MAX_SPOTS 2
-#define RADIUS 128
-#define INNER 96
+#define MAX_SPOTS 3
-uniform vec2 spots[MAX_SPOTS]; // Spotlight positions array
+struct Spot {
+ vec2 pos; // window coords of spot
+ float inner; // inner fully transparent centre radius
+ float radius; // alpha fades out to this radius
+};
+
+uniform Spot spots[MAX_SPOTS]; // Spotlight positions array
uniform float screenWidth; // Width of the screen
void main()
{
- float alpha = 0.0;
+ float alpha = 1.0;
// Get the position of the current fragment (screen coordinates!)
+
vec2 pos = vec2(gl_FragCoord.x, gl_FragCoord.y);
// Find out which spotlight is nearest
float d = 65000; // some high value
- float di = 0;
+ int fi = -1; // found index
for (int i = 0; i < MAX_SPOTS; i++)
{
- di = distance(pos, spots[i]);
- if (d > di) d = di;
+ for (int j = 0; j < MAX_SPOTS; j++)
+ {
+ float dj = distance(pos, spots[j].pos) - spots[j].radius + spots[i].radius;
+ if (d > dj )
+ {
+ d = dj;
+ fi = i;
+ }
+ }
}
// d now equals distance to nearest spot...
- if (d > RADIUS) alpha = 1.0;
- else
- {
- if (d < INNER) alpha = 0.0;
- else alpha = (d - INNER)/(RADIUS - INNER);
+ // allowing for the different radii of all spotlights
+ if (fi != -1) {
+
+ if (d > spots[fi].radius)
+ {
+ alpha = 1.0;
+ }
+ else
+ {
+ if (d < spots[fi].inner)
+ {
+ alpha = 0.0;
+ }
+ else
+ {
+ alpha = (d - spots[fi].inner) / (spots[fi].radius - spots[fi].inner);
+ }
+ }
}
// Right hand side of screen is dimly lit,
diff --git a/examples/shaders/shaders_spotlight.c b/examples/shaders/shaders_spotlight.c
index 5955d96cf..944f3d588 100644
--- a/examples/shaders/shaders_spotlight.c
+++ b/examples/shaders/shaders_spotlight.c
@@ -39,9 +39,24 @@
#define GLSL_VERSION 100
#endif
-#define MAXSPOT 2
+
+#define MAXSPOT 3 // NB must be the same as define in shader
#define numStars 400
+
+// Spot data
+typedef struct {
+ Vector2 pos;
+ Vector2 vel;
+ float inner;
+ float radius;
+
+ // Shader locations
+ unsigned int posLoc;
+ unsigned int innerLoc;
+ unsigned int radiusLoc;
+} Spot;
+
// Stars in the star field have a position and velocity
typedef struct Star {
Vector2 pos;
@@ -59,6 +74,7 @@ int main(void)
const int screenHeight = 450;
InitWindow(screenWidth, screenHeight, "raylib - shader spotlight");
+ HideCursor();
Texture texRay = LoadTexture("resources/raysan.png");
@@ -74,20 +90,32 @@ int main(void)
int frameCounter = 0;
- unsigned int spotLoc[MAXSPOT]; // shader locations
-
- Vector2 spotPos[MAXSPOT]; // position and velocity
- Vector2 spotVel[MAXSPOT];
+
// Use default vert shader
Shader spotShader = LoadShader(0, FormatText("resources/shaders/glsl%i/spotlight.fs", GLSL_VERSION));
// Get the locations of spots in the shader
- char spotName[32] = "spots[x]\0";
+ Spot spots[MAXSPOT];
+/*
+ unsigned int posLoc;
+ unsigned int innerLoc;
+ unsigned int radiusLoc;
+*/
for (int i = 0; i < MAXSPOT; i++)
{
- spotName[6] = '0' + i;
- spotLoc[i] = GetShaderLocation(spotShader, spotName);
+ char posName[32] = "spots[x].pos\0";
+ char innerName[32] = "spots[x].inner\0";
+ char radiusName[32] = "spots[x].radius\0";
+
+ posName[6] = '0' + i;
+ innerName[6] = '0' + i;
+ radiusName[6] = '0' + i;
+
+ spots[i].posLoc = GetShaderLocation(spotShader, posName);
+ spots[i].innerLoc = GetShaderLocation(spotShader, innerName);
+ spots[i].radiusLoc = GetShaderLocation(spotShader, radiusName);
+
}
// tell the shader how wide the screen is so we can have
@@ -99,17 +127,26 @@ int main(void)
}
// randomise the locations and velocities of the spotlights
+ // and initialise the shader locations
for (int i = 0; i < MAXSPOT; i++)
{
- spotPos[i].x = GetRandomValue(64, screenWidth - 64);
- spotPos[i].y = GetRandomValue(64, screenHeight - 64);
- spotVel[i] = (Vector2){ 0, 0 };
+
+ spots[i].pos.x = GetRandomValue(64, screenWidth - 64);
+ spots[i].pos.y = GetRandomValue(64, screenHeight - 64);
+ spots[i].vel = (Vector2){ 0, 0 };
- while ((fabs(spotVel[i].x) + fabs(spotVel[i].y)) < 2)
+ while ((fabs(spots[i].vel.x) + fabs(spots[i].vel.y)) < 2)
{
- spotVel[i].x = GetRandomValue(-40, 40)/10.0;
- spotVel[i].y = GetRandomValue(-40, 40)/10.0;
+ spots[i].vel.x = GetRandomValue(-40, 40)/10.0;
+ spots[i].vel.y = GetRandomValue(-40, 40)/10.0;
}
+
+ spots[i].inner = 28 * (i + 1);
+ spots[i].radius = 48 * (i + 1);
+
+ SetShaderValue(spotShader, spots[i].posLoc, &spots[i].pos.x, UNIFORM_VEC2);
+ SetShaderValue(spotShader, spots[i].innerLoc, &spots[i].inner, UNIFORM_FLOAT);
+ SetShaderValue(spotShader, spots[i].radiusLoc, &spots[i].radius, UNIFORM_FLOAT);
}
SetTargetFPS(60); // Set to run at 60 frames-per-second
@@ -128,15 +165,21 @@ int main(void)
// Update the spots, send them to the shader
for (int i = 0; i < MAXSPOT; i++)
{
- spotPos[i].x += spotVel[i].x;
- spotPos[i].y += spotVel[i].y;
-
- if (spotPos[i].x < 64) spotVel[i].x = -spotVel[i].x;
- if (spotPos[i].x > screenWidth - 64) spotVel[i].x = -spotVel[i].x;
- if (spotPos[i].y < 64) spotVel[i].y = -spotVel[i].y;
- if (spotPos[i].y > screenHeight - 64) spotVel[i].y = -spotVel[i].y;
+ if ( i == 0 ) {
+ Vector2 mp = GetMousePosition();
+ spots[i].pos.x = mp.x;
+ spots[i].pos.y = screenHeight - mp.y;
+ } else {
+ spots[i].pos.x += spots[i].vel.x;
+ spots[i].pos.y += spots[i].vel.y;
+
+ if (spots[i].pos.x < 64) spots[i].vel.x = -spots[i].vel.x;
+ if (spots[i].pos.x > screenWidth - 64) spots[i].vel.x = -spots[i].vel.x;
+ if (spots[i].pos.y < 64) spots[i].vel.y = -spots[i].vel.y;
+ if (spots[i].pos.y > screenHeight - 64) spots[i].vel.y = -spots[i].vel.y;
+ }
- SetShaderValue(spotShader, spotLoc[i], &spotPos[i].x, UNIFORM_VEC2);
+ SetShaderValue(spotShader, spots[i].posLoc, &spots[i].pos.x, UNIFORM_VEC2);
}
// Draw
@@ -170,6 +213,11 @@ int main(void)
EndShaderMode();
DrawFPS(10, 10);
+
+ DrawText("Move the mouse!", 10, 30, 20, GREEN);
+ DrawText("Pitch Black", screenWidth * .2, screenHeight / 2, 20, GREEN);
+ DrawText("Dark", screenWidth * .66, screenHeight / 2, 20, GREEN);
+
EndDrawing();
//----------------------------------------------------------------------------------