Fix: Detect collision if one line is almost vertical (#5510) (#5531)

Co-authored-by: maiconpintoabreu <maicon@thinkpad02.exads.com>

CONTRIBUTING.md

@@ -4,7 +4,7 @@ Hello contributors! Welcome to raylib!
 
 Do you enjoy raylib and want to contribute? Nice! You can help with the following points:
 
-- `C programming` - Can you write/review/test/improve the code? 
+- `C programming` - Can you write/review/test/improve the code?
 - `Documentation/Tutorials/Example` - Can you write some tutorials/examples?
 - `Porting to other platforms` - Can you port/adapt/compile raylib on other systems?
 - `Web Development` - Can you help [with the website](https://github.com/raysan5/raylib.com)?

examples/shaders/resources/shaders/glsl100/ascii.fs

@@ -44,7 +44,7 @@ float GetCharacter(float n, vec2 p)
 // Main shader logic
 // -----------------------------------------------------------------------------
 
-void main() 
+void main()
 {
     vec2 charPixelSize = vec2(fontSize, fontSize);
     vec2 uvCellSize = charPixelSize/resolution;

examples/shaders/resources/shaders/glsl100/hybrid_raymarch.fs

@@ -63,7 +63,7 @@ float sdSixWayCutHollowSphere(vec3 p, float r, float h, float t)
 }
 
 // SRC: https://iquilezles.org/articles/boxfunctions
-vec2 iBox(in vec3 ro, in vec3 rd, in vec3 rad) 
+vec2 iBox(in vec3 ro, in vec3 rd, in vec3 rad)
 {
     vec3 m = 1.0/rd;
     vec3 n = m*ro;

examples/shaders/resources/shaders/glsl100/wave.fs

@@ -19,7 +19,8 @@ uniform float ampY;
 uniform float speedX;
 uniform float speedY;
 
-void main() {
+void main()
+{
     float pixelWidth = 1.0/size.x;
     float pixelHeight = 1.0/size.y;
     float aspect = pixelHeight/pixelWidth;

examples/shaders/resources/shaders/glsl120/ascii.fs

@@ -42,7 +42,7 @@ float GetCharacter(float n, vec2 p)
 // Main shader logic
 // -----------------------------------------------------------------------------
 
-void main() 
+void main()
 {
     vec2 charPixelSize = vec2(fontSize, fontSize);
     vec2 uvCellSize = charPixelSize / resolution;

examples/shaders/resources/shaders/glsl120/hybrid_raymarch.fs

@@ -61,7 +61,7 @@ float sdSixWayCutHollowSphere(vec3 p, float r, float h, float t)
 }
 
 // SRC: https://iquilezles.org/articles/boxfunctions
-vec2 iBox(in vec3 ro, in vec3 rd, in vec3 rad) 
+vec2 iBox(in vec3 ro, in vec3 rd, in vec3 rad)
 {
     vec3 m = 1.0/rd;
     vec3 n = m*ro;

examples/shaders/resources/shaders/glsl120/wave.fs

@@ -17,7 +17,8 @@ uniform float ampY;
 uniform float speedX;
 uniform float speedY;
 
-void main() {
+void main()
+{
     float pixelWidth = 1.0/size.x;
     float pixelHeight = 1.0/size.y;
     float aspect = pixelHeight/pixelWidth;

examples/shaders/resources/shaders/glsl330/ascii.fs

@@ -38,7 +38,7 @@ float GetCharacter(int n, vec2 p)
 // Main shader logic
 // -----------------------------------------------------------------------------
 
-void main() 
+void main()
 {
     vec2 charPixelSize = vec2(fontSize, fontSize);
     vec2 uvCellSize = charPixelSize/resolution;

examples/shaders/resources/shaders/glsl330/deferred_shading.fs

@@ -23,7 +23,8 @@ uniform vec3 viewPosition;
 const float QUADRATIC = 0.032;
 const float LINEAR = 0.09;
 
-void main() {
+void main()
+{
     vec3 fragPosition = texture(gPosition, texCoord).rgb;
     vec3 normal = texture(gNormal, texCoord).rgb;
     vec3 albedo = texture(gAlbedoSpec, texCoord).rgb;

examples/shaders/resources/shaders/glsl330/deferred_shading.vs

@@ -5,7 +5,8 @@ layout (location = 1) in vec2 vertexTexCoord;
 
 out vec2 texCoord;
 
-void main() {
+void main()
+{
     gl_Position = vec4(vertexPosition, 1.0);
     texCoord = vertexTexCoord;
 }

examples/shaders/resources/shaders/glsl330/gbuffer.fs

@@ -10,7 +10,8 @@ in vec3 fragNormal;
 uniform sampler2D diffuseTexture;
 uniform sampler2D specularTexture;
 
-void main() {
+void main()
+{
     // store the fragment position vector in the first gbuffer texture
     gPosition = fragPosition;
     // also store the per-fragment normals into the gbuffer

examples/shaders/resources/shaders/glsl330/hybrid_raymarch.fs

@@ -59,7 +59,7 @@ float sdSixWayCutHollowSphere(vec3 p, float r, float h, float t)
 }
 
 // https://iquilezles.org/articles/boxfunctions
-vec2 iBox(in vec3 ro, in vec3 rd, in vec3 rad) 
+vec2 iBox(in vec3 ro, in vec3 rd, in vec3 rad)
 {
     vec3 m = 1.0/rd;
     vec3 n = m*ro;

examples/shaders/resources/shaders/glsl330/wave.fs

@@ -22,7 +22,8 @@ uniform float ampY;
 uniform float speedX;
 uniform float speedY;
 
-void main() {
+void main()
+{
     float pixelWidth = 1.0/size.x;
     float pixelHeight = 1.0/size.y;
     float aspect = pixelHeight/pixelWidth;

examples/shapes/shapes_ball_physics.c

@@ -139,14 +139,14 @@ int main(void)
             Ball *ball = &balls[i];
 
             // The ball is not grabbed
-            if (!ball->grabbed) 
+            if (!ball->grabbed)
             {
                 // Ball repositioning using the velocity
                 ball->pos.x += ball->vel.x * delta;
                 ball->pos.y += ball->vel.y * delta;
 
                 // Does the ball hit the screen right boundary?
-                if ((ball->pos.x + ball->radius) >= screenWidth) 
+                if ((ball->pos.x + ball->radius) >= screenWidth)
                 {
                     ball->pos.x = screenWidth - ball->radius; // Ball repositioning
                     ball->vel.x = -ball->vel.x*ball->elasticity;  // Elasticity makes the ball lose 10% of its velocity on hit
@@ -159,12 +159,12 @@ int main(void)
                 }
 
                 // The same for y axis
-                if ((ball->pos.y + ball->radius) >= screenHeight) 
+                if ((ball->pos.y + ball->radius) >= screenHeight)
                 {
                     ball->pos.y = screenHeight - ball->radius;
                     ball->vel.y = -ball->vel.y*ball->elasticity;
                 } 
-                else if ((ball->pos.y - ball->radius) <= 0) 
+                else if ((ball->pos.y - ball->radius) <= 0)
                 { 
                     ball->pos.y = ball->radius;
                     ball->vel.y = -ball->vel.y*ball->elasticity;

projects/4coder/main.c

@@ -1,7 +1,8 @@
 #include <math.h>
 #include "raylib.h"
 
-int main() {
+int main()
+{
     int screenWidth = 800;
     int screenHeight = 450;
 
@@ -17,7 +18,8 @@ int main() {
 
     SetTargetFPS(60);
 
-    while (!WindowShouldClose()) {
+    while (!WindowShouldClose())
+    {
         cam.position.x = sin(GetTime())*10.0f;
         cam.position.z = cos(GetTime())*10.0f;
 

src/platforms/rcore_web.c

@@ -894,7 +894,8 @@ void SwapScreenBuffer(void)
         const canvas = Module.canvas;
         const ctx = canvas.getContext('2d');
 
-        if (!Module.__img || (Module.__img.width !== width) || (Module.__img.height !== height)) {
+        if (!Module.__img || (Module.__img.width !== width) || (Module.__img.height !== height))
+        {
             Module.__img = ctx.createImageData(width, height);
         }
 

src/platforms/rcore_web_emscripten.c

@@ -875,7 +875,8 @@ void SwapScreenBuffer(void)
         //const canvas = Module['canvas'];
         const ctx = canvas.getContext('2d');
 
-        if (!Module.__img || (Module.__img.width !== width) || (Module.__img.height !== height)) {
+        if (!Module.__img || (Module.__img.width !== width) || (Module.__img.height !== height))
+        {
             Module.__img = ctx.createImageData(width, height);
         }
 

src/rshapes.c

@@ -2365,30 +2365,30 @@ bool CheckCollisionCircleRec(Vector2 center, float radius, Rectangle rec)
 // Check the collision between two lines defined by two points each, returns collision point by reference
 bool CheckCollisionLines(Vector2 startPos1, Vector2 endPos1, Vector2 startPos2, Vector2 endPos2, Vector2 *collisionPoint)
 {
-    bool collision = false;
+    // According to https://en.wikipedia.org/wiki/Line–line_intersection#Given_two_points_on_each_line_segment
+    float rx = endPos1.x - startPos1.x;
+    float ry = endPos1.y - startPos1.y;
+    float sx = endPos2.x - startPos2.x;
+    float sy = endPos2.y - startPos2.y;
 
-    float div = (endPos2.y - startPos2.y)*(endPos1.x - startPos1.x) - (endPos2.x - startPos2.x)*(endPos1.y - startPos1.y);
+    float div = rx * sy - ry * sx;
 
-    if (fabsf(div) >= FLT_EPSILON)
+    if (fabsf(div) < FLT_EPSILON) {
-    {
+        return false;
-        collision = true;
-
-        float xi = ((startPos2.x - endPos2.x)*(startPos1.x*endPos1.y - startPos1.y*endPos1.x) - (startPos1.x - endPos1.x)*(startPos2.x*endPos2.y - startPos2.y*endPos2.x))/div;
-        float yi = ((startPos2.y - endPos2.y)*(startPos1.x*endPos1.y - startPos1.y*endPos1.x) - (startPos1.y - endPos1.y)*(startPos2.x*endPos2.y - startPos2.y*endPos2.x))/div;
-
-        if (((fabsf(startPos1.x - endPos1.x) > FLT_EPSILON) && (xi < fminf(startPos1.x, endPos1.x) || (xi > fmaxf(startPos1.x, endPos1.x)))) ||
-            ((fabsf(startPos2.x - endPos2.x) > FLT_EPSILON) && (xi < fminf(startPos2.x, endPos2.x) || (xi > fmaxf(startPos2.x, endPos2.x)))) ||
-            ((fabsf(startPos1.y - endPos1.y) > FLT_EPSILON) && (yi < fminf(startPos1.y, endPos1.y) || (yi > fmaxf(startPos1.y, endPos1.y)))) ||
-            ((fabsf(startPos2.y - endPos2.y) > FLT_EPSILON) && (yi < fminf(startPos2.y, endPos2.y) || (yi > fmaxf(startPos2.y, endPos2.y))))) collision = false;
-
-        if (collision && (collisionPoint != 0))
-        {
-            collisionPoint->x = xi;
-            collisionPoint->y = yi;
-        }
     }
 
-    return collision;
+    float s12x = startPos2.x - startPos1.x;
+    float s12y = startPos2.y - startPos1.y;
+
+    float t = (s12x * sy - s12y * sx) / div;
+    float u = (s12x * ry - s12y * rx) / div;
+
+    if (0.0f <= t && t <= 1.0f && 0.0f <= u && u <= 1.0f) {
+        collisionPoint->x = startPos1.x + t * rx;
+        collisionPoint->y = startPos1.y + t * ry;
+        return true;
+    }
+    return false;
 }
 
 // Check if point belongs to line created between two points [p1] and [p2] with defined margin in pixels [threshold]

tools/rlparser/rlparser.c

@@ -721,7 +721,8 @@ int main(int argc, char *argv[])
                             char v = structs[i].fieldType[originalIndex][k];
                             if ((v == '*') || (v == ' ') || (v == ','))
                             {
-                                if (nameEnd != -1) {
+                                if (nameEnd != -1)
+                                {
                                     // Don't copy to last additional field
                                     if (fieldsRemaining != additionalFields)
                                     {
@@ -1011,7 +1012,8 @@ int main(int argc, char *argv[])
                     ((linePtr[c - 4] == 'v') &&
                      (linePtr[c - 3] == 'o') &&
                      (linePtr[c - 2] == 'i') &&
-                     (linePtr[c - 1] == 'd'))) {
+                     (linePtr[c - 1] == 'd')))
+                {
                   break;
                 }