From d81394156a9549338ae0f31fdd30d809156acfe9 Mon Sep 17 00:00:00 2001
From: ExMix <rahuba.youri@mapswithme.com>
Date: Tue, 13 Jan 2015 15:23:46 +0300
Subject: [PATCH] [drape] texture coord generation for stipple lines

---
 drape_frontend/line_shape.cpp | 177 ++++++++++++++++++++++++++++------
 1 file changed, 147 insertions(+), 30 deletions(-)

diff --git a/drape_frontend/line_shape.cpp b/drape_frontend/line_shape.cpp
index 0b6c8f7868..eb434dcffe 100644
--- a/drape_frontend/line_shape.cpp
+++ b/drape_frontend/line_shape.cpp
@@ -18,6 +18,70 @@ namespace
   float const CAP = 1.0f;
   float const LEFT_WIDTH = 1.0f;
   float const RIGHT_WIDTH = -1.0f;
+  size_t const TEX_BEG_IDX = 0;
+  size_t const TEX_END_IDX = 1;
+
+  struct TexDescription
+  {
+    float m_globalLength;
+    glsl::vec2 m_texCoord;
+  };
+
+  class TextureCoordGenerator
+  {
+  public:
+    TextureCoordGenerator(float const baseGtoPScale)
+      : m_baseGtoPScale(baseGtoPScale)
+      , m_basePtoGScale(1.0f / baseGtoPScale)
+    {
+    }
+
+    void SetRegion(dp::TextureManager::StippleRegion const & region, bool isSolid)
+    {
+      m_isSolid = isSolid;
+      m_region = region;
+      if (!m_isSolid)
+      {
+        m_maskLength = static_cast<float>(m_region.GetMaskPixelLength());
+        m_patternLength = static_cast<float>(m_region.GetPatternPixelLength());
+      }
+    }
+
+    bool GetTexCoords(TexDescription & desc)
+    {
+      if (m_isSolid)
+      {
+        desc.m_texCoord = glsl::ToVec2(m_region.GetTexRect().Center());
+        return true;
+      }
+
+      float const pxLength = desc.m_globalLength * m_baseGtoPScale;
+      float const maskRest = m_maskLength - m_pxCursor;
+
+      m2::RectF const & texRect = m_region.GetTexRect();
+      if (maskRest < pxLength)
+      {
+        desc.m_globalLength = maskRest * m_basePtoGScale;
+        desc.m_texCoord = glsl::vec2(texRect.maxX(), texRect.Center().y);
+        return false;
+      }
+
+      float texX = texRect.minX() + ((m_pxCursor + pxLength) / m_maskLength) * texRect.SizeX();
+      m_pxCursor = fmodf(m_pxCursor + pxLength, m_patternLength);
+
+      desc.m_texCoord = glsl::vec2(texX, texRect.Center().y);
+      return true;
+    }
+
+  private:
+    float const m_baseGtoPScale;
+    float const m_basePtoGScale;
+    dp::TextureManager::StippleRegion m_region;
+    float m_maskLength = 0.0f;
+    float m_patternLength = 0.0f;
+    bool m_isSolid = true;
+    float m_pxCursor = 0.0f;
+  };
 }
 
 LineShape::LineShape(m2::SharedSpline const & spline,
@@ -30,6 +94,7 @@ LineShape::LineShape(m2::SharedSpline const & spline,
 
 void LineShape::Draw(dp::RefPointer<dp::Batcher> batcher, dp::RefPointer<dp::TextureManager> textures) const
 {
+  typedef gpu::LineVertex LV;
   buffer_vector<gpu::LineVertex, 128> geometry;
   vector<m2::PointD> const & path = m_spline->GetPath();
 
@@ -37,19 +102,24 @@ void LineShape::Draw(dp::RefPointer<dp::Batcher> batcher, dp::RefPointer<dp::Tex
   textures->GetColorRegion(m_params.m_color, colorRegion);
   glsl::vec2 colorCoord(glsl::ToVec2(colorRegion.GetTexRect().Center()));
 
+  TextureCoordGenerator texCoordGen(m_params.m_baseGtoPScale);
   dp::TextureManager::StippleRegion maskRegion;
-  textures->GetStippleRegion(dp::TextureManager::TStipplePattern{1}, maskRegion);
-  glsl::vec2 maskCoord(glsl::ToVec2(maskRegion.GetTexRect().Center()));
+  if (m_params.m_pattern.empty())
+    textures->GetStippleRegion(dp::TextureManager::TStipplePattern{1}, maskRegion);
+  else
+    textures->GetStippleRegion(m_params.m_pattern, maskRegion);
 
+  texCoordGen.SetRegion(maskRegion, m_params.m_pattern.empty());
   float const halfWidth = m_params.m_width / 2.0f;
+  float const glbHalfWidth = halfWidth / m_params.m_baseGtoPScale;
   bool generateCap = m_params.m_cap != dp::ButtCap;
 
   auto const calcTangentAndNormals = [&halfWidth](glsl::vec2 const & pt0, glsl::vec2 const & pt1,
                                         glsl::vec2 & tangent, glsl::vec2 & leftNormal,
                                         glsl::vec2 & rightNormal)
   {
-    tangent = pt1 - pt0;
-    leftNormal = halfWidth * glsl::normalize(glsl::vec2(tangent.y, -tangent.x));
+    tangent = glsl::normalize(pt1 - pt0);
+    leftNormal = halfWidth * glsl::vec2(tangent.y, -tangent.x);
     rightNormal = -leftNormal;
   };
 
@@ -58,22 +128,30 @@ void LineShape::Draw(dp::RefPointer<dp::Batcher> batcher, dp::RefPointer<dp::Tex
   glsl::vec2 leftSegment(SEGMENT, LEFT_WIDTH);
   glsl::vec2 rightSegment(SEGMENT, RIGHT_WIDTH);
 
+  TexDescription texCoords[2];
+
   if (generateCap)
   {
     glsl::vec2 startPoint = glsl::ToVec2(path[0]);
     glsl::vec2 endPoint = glsl::ToVec2(path[1]);
     glsl::vec2 tangent, leftNormal, rightNormal;
     calcTangentAndNormals(startPoint, endPoint, tangent, leftNormal, rightNormal);
-    tangent = -halfWidth * glsl::normalize(tangent);
+    tangent = -halfWidth * tangent;
 
     glsl::vec3 pivot = glsl::vec3(startPoint, m_params.m_depth);
     glsl::vec2 leftCap(capType, LEFT_WIDTH);
     glsl::vec2 rightCap(capType, RIGHT_WIDTH);
 
-    geometry.push_back(gpu::LineVertex(pivot, leftNormal + tangent, colorCoord, maskCoord, leftCap));
-    geometry.push_back(gpu::LineVertex(pivot, rightNormal + tangent, colorCoord, maskCoord, rightCap));
-    geometry.push_back(gpu::LineVertex(pivot, leftNormal, colorCoord, maskCoord, leftSegment));
-    geometry.push_back(gpu::LineVertex(pivot, rightNormal, colorCoord, maskCoord, rightSegment));
+    texCoords[TEX_BEG_IDX].m_globalLength = 0.0;
+    texCoords[TEX_END_IDX].m_globalLength = glbHalfWidth;
+
+    VERIFY(texCoordGen.GetTexCoords(texCoords[TEX_BEG_IDX]), ());
+    VERIFY(texCoordGen.GetTexCoords(texCoords[TEX_END_IDX]), ());
+
+    geometry.push_back(LV(pivot, leftNormal + tangent, colorCoord, texCoords[TEX_BEG_IDX].m_texCoord, leftCap));
+    geometry.push_back(LV(pivot, rightNormal + tangent, colorCoord, texCoords[TEX_BEG_IDX].m_texCoord, rightCap));
+    geometry.push_back(LV(pivot, leftNormal, colorCoord, texCoords[TEX_END_IDX].m_texCoord, leftSegment));
+    geometry.push_back(LV(pivot, rightNormal, colorCoord, texCoords[TEX_END_IDX].m_texCoord, rightSegment));
   }
 
   glsl::vec2 prevPoint;
@@ -108,26 +186,39 @@ void LineShape::Draw(dp::RefPointer<dp::Batcher> batcher, dp::RefPointer<dp::Tex
 
       if (m_params.m_join == dp::BevelJoin)
       {
-        geometry.push_back(gpu::LineVertex(startPivot, prevForming, colorCoord, maskCoord, leftSegment));
-        geometry.push_back(gpu::LineVertex(startPivot, zeroNormal, colorCoord, maskCoord, leftSegment));
-        geometry.push_back(gpu::LineVertex(startPivot, nextForming, colorCoord, maskCoord, leftSegment));
-        geometry.push_back(gpu::LineVertex(startPivot, nextForming, colorCoord, maskCoord, leftSegment));
+        texCoords[TEX_BEG_IDX].m_globalLength = 0.0f;
+        texCoords[TEX_END_IDX].m_globalLength = glsl::length(nextForming - prevForming) / m_params.m_baseGtoPScale;
+        VERIFY(texCoordGen.GetTexCoords(texCoords[TEX_BEG_IDX]), ());
+        VERIFY(texCoordGen.GetTexCoords(texCoords[TEX_END_IDX]), ());
+
+        geometry.push_back(LV(startPivot, prevForming, colorCoord, texCoords[TEX_BEG_IDX].m_texCoord, leftSegment));
+        geometry.push_back(LV(startPivot, zeroNormal, colorCoord, texCoords[TEX_BEG_IDX].m_texCoord, leftSegment));
+        geometry.push_back(LV(startPivot, nextForming, colorCoord, texCoords[TEX_END_IDX].m_texCoord, leftSegment));
+        geometry.push_back(LV(startPivot, nextForming, colorCoord, texCoords[TEX_END_IDX].m_texCoord, leftSegment));
       }
       else
       {
         glsl::vec2 middleForming = glsl::normalize(prevForming + nextForming);
         glsl::vec2 zeroDxDy(0.0, 0.0);
 
+        texCoords[TEX_BEG_IDX].m_globalLength = 0.0f;
+        texCoords[TEX_END_IDX].m_globalLength = glsl::length(nextForming - prevForming) / m_params.m_baseGtoPScale;
+        TexDescription middle;
+        middle.m_globalLength = texCoords[TEX_END_IDX].m_globalLength / 2.0f;
+        VERIFY(texCoordGen.GetTexCoords(texCoords[TEX_BEG_IDX]), ());
+        VERIFY(texCoordGen.GetTexCoords(middle), ());
+        VERIFY(texCoordGen.GetTexCoords(texCoords[TEX_END_IDX]), ());
+
         if (m_params.m_join == dp::MiterJoin)
         {
           float const b = glsl::length(prevForming - nextForming) / 2.0;
           float const a = glsl::length(prevForming);
           middleForming *= static_cast<float>(sqrt(a * a + b * b));
 
-          geometry.push_back(gpu::LineVertex(startPivot, prevForming, colorCoord, maskCoord, zeroDxDy));
-          geometry.push_back(gpu::LineVertex(startPivot, zeroNormal, colorCoord, maskCoord, zeroDxDy));
-          geometry.push_back(gpu::LineVertex(startPivot, middleForming, colorCoord, maskCoord, zeroDxDy));
-          geometry.push_back(gpu::LineVertex(startPivot, nextForming, colorCoord, maskCoord, zeroDxDy));
+          geometry.push_back(LV(startPivot, prevForming, colorCoord, texCoords[TEX_BEG_IDX].m_texCoord, zeroDxDy));
+          geometry.push_back(LV(startPivot, zeroNormal, colorCoord, texCoords[TEX_BEG_IDX].m_texCoord, zeroDxDy));
+          geometry.push_back(LV(startPivot, middleForming, colorCoord, middle.m_texCoord, zeroDxDy));
+          geometry.push_back(LV(startPivot, nextForming, colorCoord, texCoords[TEX_END_IDX].m_texCoord, zeroDxDy));
         }
         else
         {
@@ -136,18 +227,38 @@ void LineShape::Draw(dp::RefPointer<dp::Batcher> batcher, dp::RefPointer<dp::Tex
           glsl::vec2 dxdyLeft(0.0, -1.0);
           glsl::vec2 dxdyRight(0.0, -1.0);
           glsl::vec2 dxdyMiddle(1.0, 1.0);
-          geometry.push_back(gpu::LineVertex(startPivot, zeroNormal, colorCoord, maskCoord, zeroDxDy));
-          geometry.push_back(gpu::LineVertex(startPivot, prevForming, colorCoord, maskCoord, dxdyLeft));
-          geometry.push_back(gpu::LineVertex(startPivot, nextForming, colorCoord, maskCoord, dxdyRight));
-          geometry.push_back(gpu::LineVertex(startPivot, middleForming, colorCoord, maskCoord, dxdyMiddle));
+          geometry.push_back(LV(startPivot, zeroNormal, colorCoord, texCoords[TEX_BEG_IDX].m_texCoord, zeroDxDy));
+          geometry.push_back(LV(startPivot, prevForming, colorCoord, texCoords[TEX_BEG_IDX].m_texCoord, dxdyLeft));
+          geometry.push_back(LV(startPivot, nextForming, colorCoord, texCoords[TEX_END_IDX].m_texCoord, dxdyRight));
+          geometry.push_back(LV(startPivot, middleForming, colorCoord, middle.m_texCoord, dxdyMiddle));
         }
       }
     }
 
-    geometry.push_back(gpu::LineVertex(startPivot, leftNormal, colorCoord, maskCoord, leftSegment));
-    geometry.push_back(gpu::LineVertex(startPivot, rightNormal, colorCoord, maskCoord, rightSegment));
-    geometry.push_back(gpu::LineVertex(endPivot, leftNormal, colorCoord, maskCoord, leftSegment));
-    geometry.push_back(gpu::LineVertex(endPivot, rightNormal, colorCoord, maskCoord, rightSegment));
+    texCoords[TEX_BEG_IDX].m_globalLength = 0.0;
+    texCoords[TEX_END_IDX].m_globalLength = glsl::length(endPoint - startPoint);
+    VERIFY(texCoordGen.GetTexCoords(texCoords[TEX_BEG_IDX]), ());
+    while (!texCoordGen.GetTexCoords(texCoords[TEX_END_IDX]))
+    {
+      glsl::vec2 newEndPoint = startPoint + tangent * texCoords[TEX_END_IDX].m_globalLength;
+      glsl::vec3 newEndPivot = glsl::vec3(newEndPoint, m_params.m_depth);
+
+      geometry.push_back(LV(startPivot, leftNormal, colorCoord, texCoords[TEX_BEG_IDX].m_texCoord, leftSegment));
+      geometry.push_back(LV(startPivot, rightNormal, colorCoord, texCoords[TEX_BEG_IDX].m_texCoord, rightSegment));
+      geometry.push_back(LV(newEndPivot, leftNormal, colorCoord, texCoords[TEX_END_IDX].m_texCoord, leftSegment));
+      geometry.push_back(LV(newEndPivot, rightNormal, colorCoord, texCoords[TEX_END_IDX].m_texCoord, rightSegment));
+
+      startPoint = newEndPoint;
+      startPivot = newEndPivot;
+
+      VERIFY(texCoordGen.GetTexCoords(texCoords[TEX_BEG_IDX]), ());
+      texCoords[TEX_END_IDX].m_globalLength = glsl::length(endPoint - startPoint);
+    }
+
+    geometry.push_back(LV(startPivot, leftNormal, colorCoord, texCoords[TEX_BEG_IDX].m_texCoord, leftSegment));
+    geometry.push_back(LV(startPivot, rightNormal, colorCoord, texCoords[TEX_BEG_IDX].m_texCoord, rightSegment));
+    geometry.push_back(LV(endPivot, leftNormal, colorCoord, texCoords[TEX_END_IDX].m_texCoord, leftSegment));
+    geometry.push_back(LV(endPivot, rightNormal, colorCoord, texCoords[TEX_END_IDX].m_texCoord, rightSegment));
 
     prevPoint = startPoint;
     prevLeftNormal = leftNormal;
@@ -161,16 +272,22 @@ void LineShape::Draw(dp::RefPointer<dp::Batcher> batcher, dp::RefPointer<dp::Tex
     glsl::vec2 endPoint = glsl::ToVec2(path[lastPointIndex]);
     glsl::vec2 tangent, leftNormal, rightNormal;
     calcTangentAndNormals(startPoint, endPoint, tangent, leftNormal, rightNormal);
-    tangent = halfWidth * glsl::normalize(tangent);
+    tangent = halfWidth * tangent;
 
     glsl::vec3 pivot = glsl::vec3(endPoint, m_params.m_depth);
     glsl::vec2 leftCap(capType, LEFT_WIDTH);
     glsl::vec2 rightCap(capType, RIGHT_WIDTH);
 
-    geometry.push_back(gpu::LineVertex(pivot, leftNormal, colorCoord, maskCoord, leftSegment));
-    geometry.push_back(gpu::LineVertex(pivot, rightNormal, colorCoord, maskCoord, rightSegment));
-    geometry.push_back(gpu::LineVertex(pivot, leftNormal + tangent, colorCoord, maskCoord, leftCap));
-    geometry.push_back(gpu::LineVertex(pivot, rightNormal + tangent, colorCoord, maskCoord, rightCap));
+    texCoords[TEX_BEG_IDX].m_globalLength = 0.0;
+    texCoords[TEX_END_IDX].m_globalLength = glbHalfWidth;
+
+    VERIFY(texCoordGen.GetTexCoords(texCoords[TEX_BEG_IDX]), ());
+    VERIFY(texCoordGen.GetTexCoords(texCoords[TEX_END_IDX]), ());
+
+    geometry.push_back(LV(pivot, leftNormal, colorCoord, texCoords[TEX_BEG_IDX].m_texCoord, leftSegment));
+    geometry.push_back(LV(pivot, rightNormal, colorCoord, texCoords[TEX_BEG_IDX].m_texCoord, rightSegment));
+    geometry.push_back(LV(pivot, leftNormal + tangent, colorCoord, texCoords[TEX_END_IDX].m_texCoord, leftCap));
+    geometry.push_back(LV(pivot, rightNormal + tangent, colorCoord, texCoords[TEX_END_IDX].m_texCoord, rightCap));
   }
 
   dp::GLState state(gpu::LINE_PROGRAM, dp::GLState::GeometryLayer);