working symbol rendering based on point sprites

This approach ahs several advantages compared to the old approach. There
is no UNO involved anymore and we have a perfect shape defined by a
mathematical formula. No need for anti-aliasing or complex calculations
on the CPU.

Change-Id: I5018eae516de3368037c4c293d937de66f38568d

chart2/opengl/symbolFragmentShader.glsl

@@ -6,17 +6,70 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
-#
+
 #version 120
 
 varying vec4 fragmentColor;
+uniform int shape;
 
 void main()
 {
     vec2 p = gl_PointCoord * 2.0 - vec2(1.0); // (0,0) in the center
-    if (abs(p.x) < abs(p.y))
-        discard;
-
+    if(shape == 0)
+    {
+    }
+    else if(shape == 1) //diamon
+    {
+        if (abs(p.x) + abs(p.y) > 1)
+            discard;
+    }
+    else if(shape == 2) // arrow
+    {
+        if(p.y < 0 && (abs(p.x) + abs(p.y)) > 1)
+            discard;
+        else if(p.y > 0 && abs(p.x) > 0.5)
+            discard;
+    }
+    else if(shape == 3) //arrow up
+    {
+        if(p.y > 0 && (abs(p.x) + abs(p.y)) > 1)
+            discard;
+        else if(p.y < 0 && abs(p.x) > 0.5)
+            discard;
+    }
+    else if(shape == 4)
+    {
+        if(p.x > 0 && (abs(p.x) + abs(p.y)) > 1)
+            discard;
+        else if(p.x < 0 && abs(p.y) > 0.5)
+            discard;
+    }
+    else if(shape == 5)
+    {
+        if(p.x < 0 && (abs(p.x) + abs(p.y)) > 1)
+            discard;
+        else if(p.x > 0 && abs(p.y) > 0.5)
+            discard;
+    }
+    else if(shape == 6)
+    {
+        if(abs(p.x) < abs(p.y))
+            discard;
+    }
+    else if(shape == 7)
+    {
+        if(abs(p.y) < abs(p.x))
+            discard;
+    }
+    else if(shape == 8)
+    {
+        if(dot(p.x, p.y) > 1)
+            discard;
+    }
+    else if(shape == 9)
+    {
+    }
+    
     gl_FragColor = fragmentColor;
 }
 

chart2/opengl/symbolVertexShader.glsl

@@ -16,9 +16,8 @@ varying vec4 fragmentColor;
 
 void main()
 {
-    gl_Position =  MVP * vec4(vPosition, 1);
+    gl_Position = MVP * vec4(vPosition, 1);
     fragmentColor = vColor;
-    gl_PointSize = 10.0;
 }
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

chart2/source/view/main/OpenGLRender.cxx

@@ -297,8 +297,9 @@ int OpenGLRender::InitOpenGL(GLWindow aWindow)
 
     m_SymbolProID = LoadShaders("symbolVertexShader", "symbolFragmentShader");
     m_SymbolVertexID = glGetAttribLocation(m_SymbolProID, "vPosition");
-    m_SymbolMatrixID = glGetAttribLocation(m_SymbolProID, "MVP");
-    m_SymbolColorID = glGetAttribLocation(m_SymbolProID, "vColor");
+    m_SymbolMatrixID = glGetUniformLocation(m_SymbolProID, "MVP");
+    m_SymbolColorID = glGetUniformLocation(m_SymbolProID, "vColor");
+    m_SymbolShapeID = glGetUniformLocation(m_SymbolProID, "shape");
 
     CHECK_GL_ERROR();
 
@@ -1204,11 +1205,13 @@ int OpenGLRender::RenderRectangleShape(bool bBorder, bool bFill)
     {
         //move the circle to the pos, and scale using the xScale and Y scale
         RectanglePointList &pointList = m_RectangleShapePointList.front();
-        PosVecf3 trans = {0, 0, 0};
-        PosVecf3 angle = {0.0f, 0.0f, 0.0f};
-        PosVecf3 scale = {1, 1, 1.0f};
-        MoveModelf(trans, angle, scale);
-        m_MVP = m_Projection * m_View * m_Model;
+        {
+            PosVecf3 trans = {0, 0, 0};
+            PosVecf3 angle = {0.0f, 0.0f, 0.0f};
+            PosVecf3 scale = {1, 1, 1.0f};
+            MoveModelf(trans, angle, scale);
+            m_MVP = m_Projection * m_View * m_Model;
+        }
 
         //render to fbo
         //fill vertex buffer
@@ -1251,6 +1254,17 @@ int OpenGLRender::RenderRectangleShape(bool bBorder, bool bFill)
         }
         if(bBorder)
         {
+            if(bFill)
+            {
+                PosVecf3 trans = {0.0, 0.0, Z_STEP };
+                PosVecf3 angle = {0.0f, 0.0f, 0.0f};
+                PosVecf3 scale = {1, 1, 1.0f};
+                MoveModelf(trans, angle, scale);
+                m_MVP = m_Projection * m_View * m_Model;
+
+                m_fZStep += Z_STEP;
+                glUniformMatrix4fv(m_BackgroundMatrixID, 1, GL_FALSE, &m_MVP[0][0]);
+            }
             SetBackGroundColor(COL_BLACK, COL_BLACK);
 
             glBindBuffer(GL_ARRAY_BUFFER, m_ColorBuffer);
@@ -1649,31 +1663,36 @@ int OpenGLRender::RenderPieSegment2DShape(float fSize, float fPosX, float fPosY)
     return 0;
 }
 
-int OpenGLRender::RenderSymbol2DShape(float x, float y, float width, float height, sal_Int32)
+int OpenGLRender::RenderSymbol2DShape(float x, float y, float , float , sal_Int32 nSymbol)
 {
     CHECK_GL_ERROR();
 
-    glDisable(GL_POINT_SMOOTH);
-    glDisable(GL_MULTISAMPLE);
-    glPointSize(10.f);
+    glPointSize(20.f);
     CHECK_GL_ERROR();
-    PosVecf3 trans = {x/OPENGL_SCALE_VALUE, y/OPENGL_SCALE_VALUE, m_fZStep};
+    PosVecf3 trans = {0.0, 0.0, 0.0};
     PosVecf3 angle = {0.0f, 0.0f, 0.0f};
-    PosVecf3 scale = {width/OPENGL_SCALE_VALUE, height/OPENGL_SCALE_VALUE, 1.0f};
+    PosVecf3 scale = {1.0, 1.0, 1.0f};
     MoveModelf(trans, angle, scale);
     m_MVP = m_Projection * m_View * m_Model;
 
-    float aPos[3] = { 0.f, 0.f, 0.f };
+    float aPos[3] = { x/OPENGL_SCALE_VALUE, y/OPENGL_SCALE_VALUE, m_fZStep };
     //fill vertex buffer
     glBindBuffer(GL_ARRAY_BUFFER, m_VertexBuffer);
+    CHECK_GL_ERROR();
     glBufferData(GL_ARRAY_BUFFER, 3 * sizeof(float), aPos, GL_STATIC_DRAW);
     CHECK_GL_ERROR();
 
     // Use our shader
     glUseProgram(m_SymbolProID);
+    CHECK_GL_ERROR();
+
     glUniform4fv(m_SymbolColorID, 1, &m_2DColor[0]);
+    glUniform1i(m_SymbolShapeID, nSymbol);
+    CHECK_GL_ERROR();
+
     glUniformMatrix4fv(m_SymbolMatrixID, 1, GL_FALSE, &m_MVP[0][0]);
 
+    CHECK_GL_ERROR();
     // 1rst attribute buffer : vertices
     glEnableVertexAttribArray(m_SymbolVertexID);
     glBindBuffer(GL_ARRAY_BUFFER, m_VertexBuffer);
@@ -1685,12 +1704,11 @@ int OpenGLRender::RenderSymbol2DShape(float x, float y, float width, float heigh
             0,                  // stride
             (void*)0            // array buffer offset
             );
-    glDrawArrays(GL_POINTS, 0, 1); // 12*3 indices starting at 0 -> 12 triangles
+    glDrawArrays(GL_POINTS, 0, 1);
 
     glDisableVertexAttribArray(m_SymbolVertexID);
+    CHECK_GL_ERROR();
     glUseProgram(0);
-    glEnable(GL_MULTISAMPLE);
-    glEnable(GL_POINT_SMOOTH);
     m_fZStep += Z_STEP;
 
     CHECK_GL_ERROR();

chart2/source/view/main/OpenGLRender.hxx

@@ -294,6 +294,7 @@ private:
     GLuint m_SymbolVertexID;
     GLuint m_SymbolMatrixID;
     GLuint m_SymbolColorID;
+    GLuint m_SymbolShapeID;
 
 #if DEBUG_POSITIONING
     GLuint m_DebugProID;