Fixed using of texture slots in shaders

5 files changed, 46 insertions, 35 deletions

diff --git a/drape/glstate.cpp b/drape/glstate.cpp
index a13b8fea7f..9a60a1a680 100644
--- a/drape/glstate.cpp
+++ b/drape/glstate.cpp
@@ -155,16 +155,12 @@ struct UniformApplyer
 
 } // namespace
 
-void ApplyUniforms(UniformValuesStorage const & uniforms, ref_ptr<GpuProgram> program)
-{
-  static UniformApplyer applyer;
-  applyer.m_program = program;
-  uniforms.ForeachValue(applyer);
-  applyer.m_program = nullptr;
-}
+uint8_t TextureState::m_usedSlots = 0;
 
-void ApplyTextures(GLState state, ref_ptr<GpuProgram> program)
+void TextureState::ApplyTextures(GLState state, ref_ptr<GpuProgram> program)
 {
+  m_usedSlots = 0;
+
   ref_ptr<Texture> tex = state.GetColorTexture();
   int8_t colorTexLoc = -1;
   if (tex != nullptr && (colorTexLoc = program->GetUniformLocation("u_colorTex")) >= 0)
@@ -173,19 +169,7 @@ void ApplyTextures(GLState state, ref_ptr<GpuProgram> program)
     tex->Bind();
     GLFunctions::glUniformValuei(colorTexLoc, 0);
     tex->SetFilter(state.GetTextureFilter());
-  }
-  else
-  {
-    // Some Android devices (Galaxy Nexus) require to reset texture state explicitly.
-    // It's caused by a bug in OpenGL driver (for Samsung Nexus, maybe others). Normally 
-    // we don't need to explicitly call glBindTexture(GL_TEXTURE2D, 0) after glUseProgram
-    // in case of the GPU-program doesn't use textures. Here we have to do it to work around
-    // graphics artefacts. The overhead isn't significant, we don't know on which devices 
-    // it may happen so do it for all Android devices.
-#ifdef OMIM_OS_ANDROID
-    GLFunctions::glActiveTexture(gl_const::GLTexture0);
-    GLFunctions::glBindTexture(0);
-#endif
+    m_usedSlots++;
   }
 
   tex = state.GetMaskTexture();
@@ -196,16 +180,21 @@ void ApplyTextures(GLState state, ref_ptr<GpuProgram> program)
     tex->Bind();
     GLFunctions::glUniformValuei(maskTexLoc, 1);
     tex->SetFilter(state.GetTextureFilter());
+    m_usedSlots++;
   }
-  else
-  {
-    // Some Android devices (Galaxy Nexus) require to reset texture state explicitly.
-    // See detailed description above.
-#ifdef OMIM_OS_ANDROID
-    GLFunctions::glActiveTexture(gl_const::GLTexture0 + 1);
-    GLFunctions::glBindTexture(0);
-#endif
-  }
+}
+
+uint8_t TextureState::GetLastUsedSlots()
+{
+  return m_usedSlots;
+}
+
+void ApplyUniforms(UniformValuesStorage const & uniforms, ref_ptr<GpuProgram> program)
+{
+  static UniformApplyer applyer;
+  applyer.m_program = program;
+  uniforms.ForeachValue(applyer);
+  applyer.m_program = nullptr;
 }
 
 void ApplyBlending(GLState state, ref_ptr<GpuProgram> program)
@@ -215,7 +204,7 @@ void ApplyBlending(GLState state, ref_ptr<GpuProgram> program)
 
 void ApplyState(GLState state, ref_ptr<GpuProgram> program)
 {
-  ApplyTextures(state, program);
+  TextureState::ApplyTextures(state, program);
   ApplyBlending(state, program);
   GLFunctions::glDepthFunc(state.GetDepthFunction());
   GLFunctions::glLineWidth(state.GetLineWidth());
diff --git a/drape/glstate.hpp b/drape/glstate.hpp
index cf42cec1e4..27f1b27d31 100644
--- a/drape/glstate.hpp
+++ b/drape/glstate.hpp
@@ -91,9 +91,18 @@ private:
   int m_lineWidth;
 };
 
+class TextureState
+{
+public:
+  static void ApplyTextures(GLState state, ref_ptr<GpuProgram> program);
+  static uint8_t GetLastUsedSlots();
+
+private:
+  static uint8_t m_usedSlots;
+};
+
 void ApplyUniforms(UniformValuesStorage const & uniforms, ref_ptr<GpuProgram> program);
 void ApplyState(GLState state, ref_ptr<GpuProgram> program);
-void ApplyTextures(GLState state, ref_ptr<GpuProgram> program);
 void ApplyBlending(GLState state, ref_ptr<GpuProgram> program);
 
 } // namespace dp
diff --git a/drape/gpu_program.cpp b/drape/gpu_program.cpp
index 919b3ce95a..7bbc23f071 100644
--- a/drape/gpu_program.cpp
+++ b/drape/gpu_program.cpp
@@ -1,5 +1,7 @@
 #include "drape/gpu_program.hpp"
 #include "drape/glfunctions.hpp"
+#include "drape/glstate.hpp"
+#include "drape/shader_def.hpp"
 #include "drape/support_manager.hpp"
 
 #include "base/assert.hpp"
@@ -12,9 +14,10 @@
 namespace dp
 {
 
-GpuProgram::GpuProgram(ref_ptr<Shader> vertexShader, ref_ptr<Shader> fragmentShader)
+GpuProgram::GpuProgram(int programIndex, ref_ptr<Shader> vertexShader, ref_ptr<Shader> fragmentShader)
   : m_vertexShader(vertexShader)
   , m_fragmentShader(fragmentShader)
+  , m_textureSlotsCount(gpu::GetTextureSlotsCount(programIndex))
 {
   m_programID = GLFunctions::glCreateProgram();
   GLFunctions::glAttachShader(m_programID, m_vertexShader->GetID());
@@ -52,6 +55,14 @@ GpuProgram::~GpuProgram()
 
 void GpuProgram::Bind()
 {
+  // Deactivate all unused textures.
+  uint8_t const usedSlots = TextureState::GetLastUsedSlots();
+  for (uint8_t i = m_textureSlotsCount; i < usedSlots; i++)
+  {
+    GLFunctions::glActiveTexture(gl_const::GLTexture0 + i);
+    GLFunctions::glBindTexture(0);
+  }
+
   GLFunctions::glUseProgram(m_programID);
 }
 
diff --git a/drape/gpu_program.hpp b/drape/gpu_program.hpp
index ce118a35a6..9346309cb3 100644
--- a/drape/gpu_program.hpp
+++ b/drape/gpu_program.hpp
@@ -16,7 +16,7 @@ namespace dp
 class GpuProgram
 {
 public:
-  GpuProgram(ref_ptr<Shader> vertexShader,
+  GpuProgram(int programIndex, ref_ptr<Shader> vertexShader,
              ref_ptr<Shader> fragmentShader);
   ~GpuProgram();
 
@@ -37,6 +37,8 @@ private:
 
   using TUniformLocations = map<string, int8_t>;
   TUniformLocations m_uniforms;
+
+  uint8_t const m_textureSlotsCount;
 };
 
 } // namespace dp
diff --git a/drape/gpu_program_manager.cpp b/drape/gpu_program_manager.cpp
index b921ef9e9f..8c51848572 100644
--- a/drape/gpu_program_manager.cpp
+++ b/drape/gpu_program_manager.cpp
@@ -71,7 +71,7 @@ ref_ptr<GpuProgram> GpuProgramManager::GetProgram(int index)
                                              programInfo.m_fragmentSource,
                                              Shader::FragmentShader);
 
-  drape_ptr<GpuProgram> program = make_unique_dp<GpuProgram>(vertexShader, fragmentShader);
+  drape_ptr<GpuProgram> program = make_unique_dp<GpuProgram>(index, vertexShader, fragmentShader);
   ref_ptr<GpuProgram> result = make_ref(program);
   m_programs.emplace(index, move(program));