Commit 628c069a authored by Maciej Suminski's avatar Maciej Suminski
Browse files

Faster circles & semicircles drawing for the shaderless OpenGL backend.... 

Faster circles & semicircles drawing for the shaderless OpenGL backend. Removed unnecessary variables and computations.
parent 332a7b4b

common/gal/opengl/opengl_gal.cpp

+42 −61
Original line number Diff line number Diff line
@@ -118,17 +118,13 @@ OPENGL_GAL::OPENGL_GAL( wxWindow* aParent, wxEvtHandler* aMouseListener, 
    gluTessProperty( tesselator, GLU_TESS_WINDING_RULE, GLU_TESS_WINDING_POSITIVE );



    // Buffered semicircle & circle vertices

    // (3 vertices per triangle) * (2 items [circle&semicircle]) * (number of points per item)

    precomputedContainer = new VBO_CONTAINER( 3 * 2 * CIRCLE_POINTS );

    // (3 vertices per triangle) * (number of points to draw a circle)

    precomputedContainer = new VBO_CONTAINER( 3 * CIRCLE_POINTS );



    // Compute the unit circles, used for speed up of the circle drawing

    verticesCircle = new VBO_ITEM( precomputedContainer );

    computeUnitCircle();

    verticesCircle->Finish();



    verticesSemiCircle = new VBO_ITEM( precomputedContainer );

    computeUnitSemiCircle();

    verticesSemiCircle->Finish();

}
@@ -137,7 +133,6 @@ OPENGL_GAL::~OPENGL_GAL() 
    glFlush();



    delete verticesCircle;

    delete verticesSemiCircle;

    delete precomputedContainer;



    // Delete the buffers
@@ -1108,30 +1103,45 @@ void OPENGL_GAL::DrawCircle( const VECTOR2D& aCenterPoint, double aRadius ) 
        if( innerScale < outerScale )

        {

            // Draw the outline

            VBO_VERTEX* circle = verticesCircle->GetVertices();

            int next;



            color4( strokeColor.r, strokeColor.g, strokeColor.b, strokeColor.a );



            Save();



            translate3( aCenterPoint.x, aCenterPoint.y, layerDepth );

            translate3( aCenterPoint.x, aCenterPoint.y, 0.0 );

            Scale( VECTOR2D( aRadius, aRadius ) );



            begin( GL_TRIANGLES );



            for( std::deque<VECTOR2D>::const_iterator it = unitCirclePoints.begin();

                    it != unitCirclePoints.end(); it++ )

            for( int i = 0; i < 3 * CIRCLE_POINTS; ++i )

            {

                double v0[] = { it->x * innerScale, it->y * innerScale };

                double v1[] = { it->x * outerScale, it->y * outerScale };

                double v2[] = { ( it + 1 )->x * innerScale, ( it + 1 )->y * innerScale };

                double v3[] = { ( it + 1 )->x * outerScale, ( it + 1 )->y * outerScale };

                // verticesCircle contains precomputed circle points interleaved with vertex

                // (0,0,0), so filled circles can be drawn as consecutive triangles, ie:

                // { 0,a,b, 0,c,d, 0,e,f, 0,g,h, ... }

                // where letters stand for consecutive circle points and 0 for (0,0,0) vertex.



                vertex3( v0[0], v0[1], 0.0 );

                vertex3( v1[0], v1[1], 0.0 );

                vertex3( v2[0], v2[1], 0.0 );

                // We have to skip all (0,0,0) vertices (every third vertex)

                if( i % 3 == 0)

                {

                    i++;

                    // Depending on the vertex, next circle point may be stored in the next vertex..

                    next = i + 1;

                }

                else

                {

                    // ..or 2 vertices away (in case it is preceded by (0,0,0) vertex)

                    next = i + 2;

                }



                vertex3( v1[0], v1[1], 0.0 );

                vertex3( v3[0], v3[1], 0.0 );

                vertex3( v2[0], v2[1], 0.0 );

                vertex3( circle[i].x * innerScale, circle[i].y * innerScale, layerDepth );

                vertex3( circle[i].x * outerScale, circle[i].y * outerScale, layerDepth );

                vertex3( circle[next].x * innerScale, circle[next].y * innerScale, layerDepth );



                vertex3( circle[i].x * outerScale, circle[i].y * outerScale, layerDepth );

                vertex3( circle[next].x * outerScale, circle[next].y * outerScale, layerDepth );

                vertex3( circle[next].x * innerScale, circle[next].y * innerScale, layerDepth );

            }



            end();
@@ -1151,14 +1161,7 @@ void OPENGL_GAL::DrawCircle( const VECTOR2D& aCenterPoint, double aRadius ) 


        if( isGrouping )

        {

            // Multiplied by 3, as this is the number of vertices in a single triangle

            VBO_VERTEX* circle = new VBO_VERTEX[CIRCLE_POINTS * 3];



            memcpy( circle, verticesCircle->GetVertices(),

                    VBO_ITEM::VertByteSize * CIRCLE_POINTS * 3 );

            currentGroup->PushVertices( circle, CIRCLE_POINTS * 3 );



            delete[] circle;

            currentGroup->PushVertices( verticesCircle->GetVertices(), CIRCLE_POINTS * 3 );

        }

        else

        {
@@ -1208,14 +1211,8 @@ void OPENGL_GAL::drawSemiCircle( const VECTOR2D& aCenterPoint, double aRadius, d 


        if( isGrouping )

        {

            // Multiplied by 3, as this is the number of vertices in a single triangle

            VBO_VERTEX* semiCircle = new VBO_VERTEX[CIRCLE_POINTS / 2 * 3];



            memcpy( semiCircle, verticesSemiCircle->GetVertices(),

                    VBO_ITEM::VertByteSize * CIRCLE_POINTS / 2 * 3 );

            currentGroup->PushVertices( semiCircle, CIRCLE_POINTS / 2 * 3 );



            delete[] semiCircle;

            // It is enough just to push just a half of the circle vertices to make a semicircle

            currentGroup->PushVertices( verticesCircle->GetVertices(), CIRCLE_POINTS / 2 * 3 );

        }

        else

        {
@@ -1668,15 +1665,16 @@ void OPENGL_GAL::computeUnitCircle() 


    // Compute the circle points for a given number of segments

    // Insert in a display list and a vector

    const VBO_VERTEX v0 = { 0.0f, 0.0f, 0.0f };



    for( int i = 0; i < CIRCLE_POINTS; i++ )

    {

        VBO_VERTEX v0 = { 0.0f, 0.0f, 0.0f };

        VBO_VERTEX v1 = {

        const VBO_VERTEX v1 = {

            cos( 2.0 * M_PI / CIRCLE_POINTS * i ),          // x

            sin( 2.0 * M_PI / CIRCLE_POINTS * i ),          // y

            0.0f                                            // z

        };

        VBO_VERTEX v2 = {

        const VBO_VERTEX v2 = {

            cos( 2.0 * M_PI / CIRCLE_POINTS * ( i + 1 ) ),  // x

            sin( 2.0 * M_PI / CIRCLE_POINTS * ( i + 1 ) ),  // y

            0.0f                                            // z
@@ -1687,11 +1685,9 @@ void OPENGL_GAL::computeUnitCircle() 


        glVertex2d( v1.x, v1.y );

        verticesCircle->PushVertex( &v1 );

        unitCirclePoints.push_back( VECTOR2D( v1.x, v1.y ) ); // TODO remove



        glVertex2d( v2.x, v2.y );

        verticesCircle->PushVertex( &v2 );

        unitCirclePoints.push_back( VECTOR2D( v2.x, v2.y ) ); // TODO remove

    }



    glEnd();
@@ -1709,26 +1705,11 @@ void OPENGL_GAL::computeUnitSemiCircle() 


    for( int i = 0; i < CIRCLE_POINTS / 2; ++i )

    {

        VBO_VERTEX v0 = { 0.0f, 0.0f, 0.0f };

        VBO_VERTEX v1 = {

            cos( 2.0 * M_PI / CIRCLE_POINTS * i ),          // x

            sin( 2.0 * M_PI / CIRCLE_POINTS * i ),          // y

            0.0f                                            // z

        };

        VBO_VERTEX v2 = {

            cos( 2.0 * M_PI / CIRCLE_POINTS * ( i + 1 ) ),  // x

            sin( 2.0 * M_PI / CIRCLE_POINTS * ( i + 1 ) ),  // y

            0.0f                                            // z

        };



        glVertex2d( 0, 0 );

        verticesSemiCircle->PushVertex( &v0 );



        glVertex2d( v1.x, v1.y );

        verticesSemiCircle->PushVertex( &v1 );



        glVertex2d( v2.x, v2.y );

        verticesSemiCircle->PushVertex( &v2 );

        glVertex2d( 0.0, 0.0 );

        glVertex2d( cos( 2.0 * M_PI / CIRCLE_POINTS * i ),

                    sin( 2.0 * M_PI / CIRCLE_POINTS * i ) );

        glVertex2d( cos( 2.0 * M_PI / CIRCLE_POINTS * ( i + 1 ) ),

                    sin( 2.0 * M_PI / CIRCLE_POINTS * ( i + 1 ) ) );

    }



    glEnd();

include/gal/opengl/opengl_gal.h

+0 −5
Original line number Diff line number Diff line
@@ -358,7 +358,6 @@ private: 
    GLuint                displayListCircle;      ///< Circle display list

    VBO_ITEM*             verticesCircle;

    GLuint                displayListSemiCircle;  ///< Semi circle display list

    VBO_ITEM*             verticesSemiCircle;



    // Vertex buffer objects related fields

    std::map<unsigned int, VBO_ITEM*> groups;     ///< Stores informations about VBO objects (groups)
@@ -374,10 +373,6 @@ private: 
    int                   indicesSize;            ///< Number of indices to be drawn

    GLuint*               indicesPtr;             ///< Pointer to mapped GPU memory



    double                curvePoints[12];        ///< Coefficients for curves

    // FIXME to be removed:

    std::deque<VECTOR2D>  unitCirclePoints;       ///< List of the points on a unit circle



    // Polygon tesselation

    GLUtesselator*        tesselator;             ///< Pointer to the tesselator

    std::vector<GLdouble*> tessIntersects;        ///< Storage of intersecting points