Merge pull request #1155 from sobotka/waveform-updates

Waveform Updates

app/shaders/rgbwaveform.frag

@@ -1,6 +1,3 @@
-// Adapted from "RGB Waveform" by lebek
-// https://www.shadertoy.com/view/4dK3Wc
-
 #version 150
 
 uniform sampler2D ove_maintex;
@@ -9,64 +6,36 @@ uniform vec2 ove_viewport;
 uniform vec3 luma_coeffs;
 
 uniform float waveform_scale;
-uniform vec2 waveform_dims;
-uniform vec4 waveform_region;
-uniform vec4 waveform_uv;
 
 in vec2 ove_texcoord;
 
 out vec4 fragColor;
 
 void main(void) {
-    vec3 col = vec3(0.0);
-    // Set an increment default to 10 bit encodings. This would likely be
-    // better served as a UI control, as waveforms will change their combing
-    // based on how granular the increment is set. For example, it can be
-    // challenging to spot 8 bit combing with an increment of 1. / 2.^8 - 1.
-    float increment = 1.0 / (pow(2, 10) - 1.0);
-    float maxb = waveform_dims.y + increment;
-    float minb = waveform_dims.y - increment;
-
-    // Intensity would make sense to also expose via the UI, as a density
-    // slider allows you to peek past certain values or reveal very low
-    // values. Hard coding it for now, as there isn't a clear way to have
-    // the various bit depth / code values always display at a consistent
-    // emission output strength.
+    float waveform_height = ceil(waveform_scale * ove_viewport.y);
+    float quantisation = 1.0 / (waveform_height - 1.0);
     float intensity = 0.10;
+    vec4 col = vec4(0.0);
+    vec4 cur_col = vec4(0.0);
+    float ratio = 0.0;
 
-    int y_lim = int(waveform_dims.y);
+    for (int i = 0; i < waveform_height; i++) {
+        ratio = float(i) / float(waveform_height - 1.0);
+        cur_col.rgb = texture(
+            ove_maintex,
+            vec2(ove_texcoord.x, ratio)
+        ).rgb;
 
-    vec3 cur_col = vec3(0.0);
-    vec3 cur_lum = vec3(0.0);
+        cur_col.w = dot(cur_col.rgb, luma_coeffs);
 
-    if (
-        (gl_FragCoord.x >= waveform_region.x) &&
-        (gl_FragCoord.y >= waveform_region.y) &&
-        (gl_FragCoord.x < waveform_region.z) &&
-        (gl_FragCoord.y < waveform_region.w)
-    ) {
-        // col = vec3(0.5, 0.5, 0.0);
-        // int start = int(waveform_region.y);
-        int stop = int(waveform_dims.y);
-        float ratio = 0.0;
-        float waveform_x = (ove_texcoord.x - waveform_uv.x) / waveform_scale;
-        float waveform_y = (ove_texcoord.y - waveform_uv.y) / waveform_scale;
-        for (int i = 0; i < waveform_dims.y; i++) {
-            ratio = float(i) / float(waveform_dims.y - 1);
-            cur_col = texture(
-                ove_maintex,
-                vec2(waveform_x, ratio)
-            ).rgb;
-
-            col += step(vec3(waveform_y - increment), cur_col) *
-                step(cur_col, vec3(waveform_y + increment)) * intensity;
-
-            cur_lum = vec3(dot(cur_col, luma_coeffs));
-
-            col += step(vec3(waveform_y - increment), cur_lum) *
-                step(cur_lum, vec3(waveform_y + increment)) * intensity;
-        }
+        col += (
+            step(vec4(ove_texcoord.y - quantisation), cur_col) *
+            step(cur_col, vec4(ove_texcoord.y + quantisation)) *
+            intensity) +
+            (step(1.0 - quantisation, ove_texcoord.y) *
+            step(vec4(1.0 - quantisation), cur_col) * intensity);
     }
 
-    fragColor = vec4(col, 1.0);
+    col.rgb += vec3(col.w);
+    fragColor = vec4(col.rgb, 1.0);
 }

app/shaders/rgbwaveform.vert

@@ -0,0 +1,29 @@
+#version 150
+
+uniform float waveform_scale;
+uniform vec2 ove_resolution;
+
+in vec4 a_position;
+in vec2 a_texcoord;
+
+out vec2 ove_texcoord;
+
+mat4 scale_mat4(vec3 scale) {
+    return mat4(
+        scale.x, 0.0, 0.0, 0.0,
+        0.0, scale.y, 0.0, 0.0,
+        0.0, 0.0, scale.z, 0.0,
+        0.0, 0.0, 0.0, 1.0
+    );
+}
+
+void main() {
+    // Create identity matrix
+    mat4 transform = mat4(1.0);
+
+    // Scale the scope
+    transform *= scale_mat4(vec3(waveform_scale, waveform_scale, 1.0));
+
+    gl_Position = transform * a_position;
+    ove_texcoord = a_texcoord;
+}

app/widget/scope/waveform/waveform.cpp

@@ -41,8 +41,10 @@ OpenGLShaderPtr WaveformScope::CreateShader()
   OpenGLShaderPtr pipeline = OpenGLShader::Create();
 
   pipeline->create();
-  pipeline->addShaderFromSourceCode(QOpenGLShader::Vertex, OpenGLShader::CodeDefaultVertex());
-  pipeline->addShaderFromSourceCode(QOpenGLShader::Fragment, Node::ReadFileAsString(":/shaders/rgbwaveform.frag"));
+  pipeline->addShaderFromSourceCode(QOpenGLShader::Vertex,
+    Node::ReadFileAsString(":/shaders/rgbwaveform.vert"));
+  pipeline->addShaderFromSourceCode(QOpenGLShader::Fragment,
+    Node::ReadFileAsString(":/shaders/rgbwaveform.frag"));
   pipeline->link();
 
   return pipeline;
@@ -51,12 +53,6 @@ OpenGLShaderPtr WaveformScope::CreateShader()
 void WaveformScope::DrawScope()
 {
   float waveform_scale = 0.80f;
-  float waveform_dim_x = width() * waveform_scale;
-  float waveform_dim_y = height() * waveform_scale;
-  float waveform_start_dim_x = (width() - waveform_dim_x) / 2.0f;
-  float waveform_start_dim_y = (height() - waveform_dim_y) / 2.0f;
-  float waveform_end_dim_x = width() - waveform_start_dim_x;
-  float waveform_end_dim_y = height() - waveform_start_dim_y;
 
   // Draw waveform through shader
   pipeline()->bind();
@@ -68,22 +64,6 @@ void WaveformScope::DrawScope()
 
   // Scale of the waveform relative to the viewport surface.
   pipeline()->setUniformValue("waveform_scale", waveform_scale);
-  pipeline()->setUniformValue(
-    "waveform_dims", waveform_dim_x, waveform_dim_y);
-
-  pipeline()->setUniformValue(
-    "waveform_region",
-    waveform_start_dim_x, waveform_start_dim_y,
-    waveform_end_dim_x, waveform_end_dim_y);
-
-  float waveform_start_uv_x = waveform_start_dim_x / width();
-  float waveform_start_uv_y = waveform_start_dim_y / height();
-  float waveform_end_uv_x = waveform_end_dim_x / width();
-  float waveform_end_uv_y = waveform_end_dim_y / height();
-  pipeline()->setUniformValue(
-    "waveform_uv",
-    waveform_start_uv_x, waveform_start_uv_y,
-    waveform_end_uv_x, waveform_end_uv_y);
 
   pipeline()->release();
 
@@ -93,9 +73,19 @@ void WaveformScope::DrawScope()
 
   managed_tex().Release();
 
+  float waveform_dim_x = ceil((width() - 1.0) * waveform_scale);
+  float waveform_dim_y = ceil((height() - 1.0) * waveform_scale);
+  float waveform_start_dim_x =
+    ((width() - 1.0) - waveform_dim_x) / 2.0f;
+  float waveform_start_dim_y =
+    ((height() - 1.0) - waveform_dim_y) / 2.0f;
+  float waveform_end_dim_x = (width() - 1.0) - waveform_start_dim_x;
+
   // Draw line overlays
   QPainter p(this);
-  QFontMetrics font_metrics = QFontMetrics(QFont());
+  QFont font;
+  font.setPixelSize(10);
+  QFontMetrics font_metrics = QFontMetrics(font);
   QString label;
   float ire_increment = 0.1f;
   int ire_steps = qRound(1.0 / ire_increment);
@@ -106,7 +96,7 @@ void WaveformScope::DrawScope()
   p.setCompositionMode(QPainter::CompositionMode_Plus);
 
   p.setPen(QColor(0.0, 0.6 * 255.0, 0.0));
-  p.setFont(QFont());
+  p.setFont(font);
 
   for (int i=0; i <= ire_steps; i++) {
     ire_lines[i].setLine(