Add offset into output buffer for edge shader

QTProject/subdivision.cpp

@@ -334,14 +334,15 @@ void Subdivision::runShader(Input input, Tables &tables) {
 
     f->glBindBuffer(GL_SHADER_STORAGE_BUFFER, 0);
 
-    runEdgeShader(tables.edge_indices.size() / 4, input.vb_handle, edge_indices_handle, output_handle);
+    int edgeOffset = input.vertex_buffer.size();
+    runEdgeShader(tables.edge_indices.size() / 4, input.vb_handle, edge_indices_handle, output_handle, edgeOffset);
 
     // Map the output buffer so we can read the results
     f->glBindBuffer(GL_SHADER_STORAGE_BUFFER, output_handle);
     Vertex *ptr;
     ptr = (Vertex *) f->glMapBuffer(GL_SHADER_STORAGE_BUFFER, GL_WRITE_ONLY);
     for (int i = 0; i < tables.edge_indices.size() / 4; i++) {
-        qDebug() << ptr[i].pos;
+        qDebug() << ptr[edgeOffset + i].pos;
     }
     f->glUnmapBuffer(GL_SHADER_STORAGE_BUFFER);
 
@@ -350,12 +351,12 @@ void Subdivision::runShader(Input input, Tables &tables) {
     f->glDeleteBuffers(1, &output_handle);
 }
 
-void Subdivision::runEdgeShader(GLuint size, GLuint vb_handle, GLuint edge_indices_handle, GLuint output_handle) {
+void Subdivision::runEdgeShader(GLuint size, GLuint vb_handle, GLuint edge_indices_handle, GLuint output_handle, GLuint offset) {
     edgeShader->bind();
 
     f->glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 0, vb_handle);
     f->glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, edge_indices_handle);
-    f->glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 2, output_handle);
+    f->glBindBufferRange(GL_SHADER_STORAGE_BUFFER, 2, output_handle, offset * sizeof(Vertex), size * sizeof(Vertex));
 
     // Run the shader
     f->glDispatchCompute(size, 1, 1);

QTProject/subdivision.h

@@ -38,7 +38,7 @@ private:
     QOpenGLShaderProgram *initComputeShaderProgram(QString &source);
     Tables precomputeTables(Input input);
     void runShader(Input input, Tables &tables);
-    void runEdgeShader(GLuint size, GLuint vb_handle, GLuint edge_indices_handle, GLuint output_handle);
+    void runEdgeShader(GLuint size, GLuint vb_handle, GLuint edge_indices_handle, GLuint output_handle, GLuint offset);
 };
 
 #endif