RetroPlayer: Fix black screen for RGB emulators on some GLES platforms

system/shaders/GLES/2.0/gles_shader_texture_noalpha.frag

@@ -0,0 +1,25 @@
+/*
+ *  Copyright (C) 2019 Team Kodi
+ *  This file is part of Kodi - https://kodi.tv
+ *
+ *  SPDX-License-Identifier: GPL-2.0-or-later
+ *  See LICENSES/README.md for more information.
+ */
+
+#version 100
+
+precision mediump float;
+uniform sampler2D m_samp0;
+varying vec4 m_cord0;
+
+void main ()
+{
+  vec3 rgb = texture2D(m_samp0, m_cord0.xy).rgb;
+
+#if defined(KODI_LIMITED_RANGE)
+  rgb *= (235.0 - 16.0) / 255.0;
+  rgb += 16.0 / 255.0;
+#endif
+
+  gl_FragColor = vec4(rgb, 1.0);
+}

xbmc/cores/RetroPlayer/rendering/RenderContext.cpp

@@ -74,6 +74,8 @@ static ESHADERMETHOD TranslateShaderMethod(GL_SHADER_METHOD method)
   case GL_SHADER_METHOD::TEXTURE: return SM_TEXTURE;
 #if defined(HAS_GLES)
   case GL_SHADER_METHOD::TEXTURE_RGBA_OES: return SM_TEXTURE_RGBA_OES;
+  case GL_SHADER_METHOD::TEXTURE_NOALPHA:
+    return SM_TEXTURE_NOALPHA;
 #endif
   default:
     break;

xbmc/cores/RetroPlayer/rendering/RenderContext.h

@@ -27,6 +27,7 @@ enum class GL_SHADER_METHOD
   DEFAULT,
   TEXTURE,
   TEXTURE_RGBA_OES,
+  TEXTURE_NOALPHA,
 };
 
 namespace KODI

xbmc/cores/RetroPlayer/rendering/VideoRenderers/RPRendererOpenGLES.cpp

@@ -255,7 +255,7 @@ void CRPRendererOpenGLES::Render(uint8_t alpha)
   glTexParameteri(m_textureTarget, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
   glTexParameteri(m_textureTarget, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 
-  m_context.EnableGUIShader(GL_SHADER_METHOD::TEXTURE);
+  m_context.EnableGUIShader(GL_SHADER_METHOD::TEXTURE_NOALPHA);
 
   GLubyte colour[4];
   GLubyte idx[4] = {0, 1, 3, 2}; // Determines order of triangle strip

xbmc/rendering/gles/RenderSystemGLES.cpp

@@ -477,6 +477,14 @@ void CRenderSystemGLES::InitialiseShaders()
       CLog::Log(LOGERROR, "GUI Shader gles_shader_rgba_bob_oes.frag - compile and link failed");
     }
   }
+
+  m_pShader[SM_TEXTURE_NOALPHA].reset(new CGLESShader("gles_shader_texture_noalpha.frag", defines));
+  if (!m_pShader[SM_TEXTURE_NOALPHA]->CompileAndLink())
+  {
+    m_pShader[SM_TEXTURE_NOALPHA]->Free();
+    m_pShader[SM_TEXTURE_NOALPHA].reset();
+    CLog::Log(LOGERROR, "GUI Shader gles_shader_texture_noalpha.frag - compile and link failed");
+  }
 }
 
 void CRenderSystemGLES::ReleaseShaders()
@@ -524,6 +532,10 @@ void CRenderSystemGLES::ReleaseShaders()
   if (m_pShader[SM_TEXTURE_RGBA_BOB_OES])
     m_pShader[SM_TEXTURE_RGBA_BOB_OES]->Free();
   m_pShader[SM_TEXTURE_RGBA_BOB_OES].reset();
+
+  if (m_pShader[SM_TEXTURE_NOALPHA])
+    m_pShader[SM_TEXTURE_NOALPHA]->Free();
+  m_pShader[SM_TEXTURE_NOALPHA].reset();
 }
 
 void CRenderSystemGLES::EnableGUIShader(ESHADERMETHOD method)

xbmc/rendering/gles/RenderSystemGLES.h

@@ -29,6 +29,7 @@ enum ESHADERMETHOD
   SM_TEXTURE_RGBA_BLENDCOLOR,
   SM_TEXTURE_RGBA_BOB,
   SM_TEXTURE_RGBA_BOB_OES,
+  SM_TEXTURE_NOALPHA,
   SM_MAX
 };