MythRenderOpenGL: Initial compute shader support

(cherry picked from commit 599a7ba)
MythTV · Mar 8, 2020 · cad10ad · cad10ad
1 parent b9ca35c
commit cad10ad
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Showing 2 changed files with 34 additions and 5 deletions.
diff --git a/mythtv/libs/libmythui/opengl/mythrenderopengl.cpp b/mythtv/libs/libmythui/opengl/mythrenderopengl.cpp
@@ -385,8 +385,13 @@ bool MythRenderOpenGL::Init(void)
     if (hasExtension("GL_NVX_gpu_memory_info"))
         m_extraFeatures |= kGLNVMemory;
 
+    // Check 16 bit FBOs
     Check16BitFBO();
 
+    // Check for compute shaders
+    if (QOpenGLShader::hasOpenGLShaders(QOpenGLShader::Compute))
+        m_extraFeatures |= kGLComputeShaders;
+
     DebugFeatures();
 
     m_extraFeaturesUsed = m_extraFeatures;
@@ -442,7 +447,7 @@ void MythRenderOpenGL::DebugFeatures(void)
     LOG(VB_GENERAL, LOG_INFO, LOC + QString("16bit framebuffers   : %1").arg(GLYesNo(m_extraFeatures & kGL16BitFBO)));
     LOG(VB_GENERAL, LOG_INFO, LOC + QString("Unpack Subimage      : %1").arg(GLYesNo(m_extraFeatures & kGLExtSubimage)));
     LOG(VB_GENERAL, LOG_INFO, LOC + QString("GL_RED/GL_R8         : %1").arg(GLYesNo(!(m_extraFeatures & kGLLegacyTextures))));
-    //LOG(VB_GENERAL, LOG_INFO, LOC + QString("Compute shaders      : %1").arg(GLYesNo(QOpenGLShader::hasOpenGLShaders(QOpenGLShader::Compute))));
+    //LOG(VB_GENERAL, LOG_INFO, LOC + QString("Compute shaders      : %1").arg(GLYesNo(m_extraFeatures & kGLComputeShaders)));
 
     // warnings
     if (m_maxTextureUnits < 3)
@@ -760,9 +765,9 @@ MythGLTexture* MythRenderOpenGL::CreateFramebufferTexture(QOpenGLFramebufferObje
         return nullptr;
 
     auto *texture = new MythGLTexture(Framebuffer->texture());
-    texture->m_size        = texture->m_totalSize = Framebuffer->size();
-    texture->m_vbo         = CreateVBO(kVertexSize);
-    texture->m_flip        = false;
+    texture->m_size = texture->m_totalSize = Framebuffer->size();
+    texture->m_vbo  = CreateVBO(kVertexSize);
+    texture->m_flip = false;
     return texture;
 }
 
@@ -1550,6 +1555,28 @@ QOpenGLShaderProgram *MythRenderOpenGL::CreateShaderProgram(const QString &Verte
     return program;
 }
 
+QOpenGLShaderProgram* MythRenderOpenGL::CreateComputeShader(const QString &Source)
+{
+    if (!(m_extraFeaturesUsed & kGLComputeShaders) || Source.isEmpty())
+        return nullptr;
+
+    OpenGLLocker locker(this);
+    auto *program = new QOpenGLShaderProgram();
+    if (!program->addShaderFromSourceCode(QOpenGLShader::Compute, Source))
+        return ShaderError(program, Source);
+
+    if (VERBOSE_LEVEL_CHECK(VB_GENERAL, LOG_DEBUG))
+    {
+        QList<QOpenGLShader*> shaders = program->shaders();
+        foreach (QOpenGLShader* shader, shaders)
+            LOG(VB_GENERAL, LOG_DEBUG, "\n" + shader->sourceCode());
+    }
+
+    if (!program->link())
+        return ShaderError(program, "");
+    return program;
+}
+
 void MythRenderOpenGL::DeleteShaderProgram(QOpenGLShaderProgram *Program)
 {
     makeCurrent();

diff --git a/mythtv/libs/libmythui/opengl/mythrenderopengl.h b/mythtv/libs/libmythui/opengl/mythrenderopengl.h
@@ -37,7 +37,8 @@ enum GLFeatures
     kGLTiled          = 0x0010,
     kGLLegacyTextures = 0x0020,
     kGLNVMemory       = 0x0040,
-    kGL16BitFBO       = 0x0080
+    kGL16BitFBO       = 0x0080,
+    kGLComputeShaders = 0x0100
 };
 
 #define TEX_OFFSET 8
@@ -136,6 +137,7 @@ class MUI_PUBLIC MythRenderOpenGL : public QOpenGLContext, public QOpenGLFunctio
     void  ClearFramebuffer(void);
 
     QOpenGLShaderProgram* CreateShaderProgram(const QString &Vertex, const QString &Fragment);
+    QOpenGLShaderProgram* CreateComputeShader(const QString &Source);
     void  DeleteShaderProgram(QOpenGLShaderProgram* Program);
     bool  EnableShaderProgram(QOpenGLShaderProgram* Program);
     void  SetShaderProgramParams(QOpenGLShaderProgram* Program, const QMatrix4x4 &Value, const char* Uniform);