1 files changed, 148 insertions, 0 deletions
diff --git a/apps/openmb/renderer/EditorHelpers.cpp b/apps/openmb/renderer/EditorHelpers.cpp
new file mode 100644
index 0000000..9531fb0
--- /dev/null
+++ b/apps/openmb/renderer/EditorHelpers.cpp
@@ -0,0 +1,148 @@
+#include "EditorHelpers.hpp"
+#include <cmath>
+
+#include <glm/gtc/matrix_inverse.hpp>
+#include <vector>
+
+namespace renderer {
+namespace editor {
+Mesh makeWireCube ( float size ) {
+    float              h     = size * 0.5f;
+    std::vector<float> verts = {
+        -h, -h, -h, h, -h, -h, h, -h, -h, h, -h, h, h, -h, h, -h, -h, h, -h, -h, h, -h, -h, -h,
+
+        -h, h, -h, h, h, -h, h, h, -h, h, h, h, h, h, h, -h, h, h, -h, h, h, -h, h, -h,
+
+        -h, -h, -h, -h, h, -h, h, -h, -h, h, h, -h, h, -h, h, h, h, h, -h, -h, h, -h, h, h };
+
+    Mesh m;
+    m.createFromPositions( verts, true );
+    return m;
+}
+
+Mesh makeCircleWire ( float radius, int segments ) {
+    if( segments < 3 )
+        segments = 3;
+
+    std::vector<float> verts;
+    verts.reserve( segments * 3 );
+
+    const float twoPi = 6.28318530717958647692f;
+
+    for( int i = 0; i < segments; ++i ) {
+        int   ni   = ( i + 1 ) % segments;
+        float ti   = (float)i / (float)segments;
+        float angi = ti * twoPi;
+        float xi   = cosf( angi ) * radius;
+        float zi   = sinf( angi ) * radius;
+
+        float tni   = (float)ni / (float)segments;
+        float angni = tni * twoPi;
+        float xni   = cosf( angni ) * radius;
+        float zni   = sinf( angni ) * radius;
+
+        verts.push_back( xi );
+        verts.push_back( 0.0f );
+        verts.push_back( zi );
+
+        verts.push_back( xni );
+        verts.push_back( 0.0f );
+        verts.push_back( zni );
+    }
+
+    Mesh m;
+    m.createFromPositions( verts, true );
+    return m;
+}
+
+Mesh makeCircleFilled ( float radius, int segments ) {
+    if( segments < 3 )
+        segments = 3;
+
+    std::vector<float> data;
+    data.reserve( ( segments + 2 ) * 5 );
+
+    const float twoPi = 6.28318530717958647692f;
+
+    float cx = 0.0f, cz = 0.0f;
+    float cu = 0.5f, cv = 0.5f;
+
+    for( int i = 0; i < segments; ++i ) {
+        int i1 = i;
+        int i2 = ( i + 1 ) % segments;
+
+        float t1   = (float)i1 / (float)segments;
+        float ang1 = t1 * twoPi;
+        float x1   = cosf( ang1 ) * radius;
+        float z1   = sinf( ang1 ) * radius;
+        float u1   = ( x1 / ( radius * 2.0f ) ) + 0.5f;
+        float v1   = ( z1 / ( radius * 2.0f ) ) + 0.5f;
+
+        float t2   = (float)i2 / (float)segments;
+        float ang2 = t2 * twoPi;
+        float x2   = cosf( ang2 ) * radius;
+        float z2   = sinf( ang2 ) * radius;
+        float u2   = ( x2 / ( radius * 2.0f ) ) + 0.5f;
+        float v2   = ( z2 / ( radius * 2.0f ) ) + 0.5f;
+
+        data.push_back( cx );
+        data.push_back( 0.0f );
+        data.push_back( cz );
+        data.push_back( cu );
+        data.push_back( cv );
+
+        data.push_back( x1 );
+        data.push_back( 0.0f );
+        data.push_back( z1 );
+        data.push_back( u1 );
+        data.push_back( v1 );
+
+        data.push_back( x2 );
+        data.push_back( 0.0f );
+        data.push_back( z2 );
+        data.push_back( u2 );
+        data.push_back( v2 );
+    }
+
+    Mesh m;
+    m.createFromPosTex( data );
+    return m;
+}
+
+bool makeRayFromMouse ( const glm::vec2& mousePx, int fbw, int fbh, const glm::mat4& view,
+                        const glm::mat4& proj, const glm::vec3& camPos, glm::vec3& outOrigin,
+                        glm::vec3& outDir ) {
+    if( fbw <= 0 || fbh <= 0 )
+        return false;
+
+    float ndcX = ( mousePx.x / (float)fbw ) * 2.0f - 1.0f;
+    float ndcY = 1.0f - ( mousePx.y / (float)fbh ) * 2.0f;
+
+    glm::vec4 nearPointNDC( ndcX, ndcY, -1.0f, 1.0f );
+    glm::vec4 farPointNDC( ndcX, ndcY, 1.0f, 1.0f );
+
+    glm::mat4 invPV = glm::inverse( proj * view );
+
+    glm::vec4 nearWorld = invPV * nearPointNDC;
+    glm::vec4 farWorld  = invPV * farPointNDC;
+    if( nearWorld.w == 0.0f || farWorld.w == 0.0f )
+        return false;
+
+    nearWorld /= nearWorld.w;
+    farWorld /= farWorld.w;
+
+    glm::vec3 nearPos = glm::vec3( nearWorld );
+    glm::vec3 farPos  = glm::vec3( farWorld );
+
+    outOrigin = nearPos;
+    outDir    = glm::normalize( farPos - nearPos );
+
+    if( !isfinite( outDir.x ) || !isfinite( outDir.y ) || !isfinite( outDir.z ) ) {
+        outOrigin = camPos;
+        outDir    = glm::normalize( glm::vec3( 0.0f, 0.0f, -1.0f ) );
+    }
+
+    return true;
+}
+}   // namespace editor
+}   // namespace renderer