Update Waveform Output

Updates:
 * Added IRE text on 20% increments
 * Added waveform lines that work
 * Scaled waveform to a subsection of the surface

app/shaders/rgbwaveform.frag

@@ -8,6 +8,11 @@ uniform vec2 ove_resolution;
 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;
@@ -19,8 +24,8 @@ void main(void) {
     // 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 = ove_texcoord.y + increment;
-    float minb = ove_texcoord.y - increment;
+    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
@@ -29,29 +34,38 @@ void main(void) {
     // emission output strength.
     float intensity = 0.10;
 
-    int y_lim = int(ove_resolution.y);
+    int y_lim = int(waveform_dims.y);
 
     vec3 cur_col = vec3(0.0);
     vec3 cur_lum = vec3(0.0);
-    for (int i = 0; i < y_lim; i++) {
-        cur_col = texture2D(
-            ove_maintex,
-            vec2(ove_texcoord.x, float(i) / float(ove_resolution.y))
-        ).rgb;
 
-        col += step(vec3(ove_texcoord.y - increment), cur_col) *
-            step(cur_col, vec3(ove_texcoord.y + increment)) * intensity;
+    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);
+            cur_col = texture2D(
+                ove_maintex,
+                vec2(waveform_x, ratio)
+            ).rgb;
 
-        // TODO: Implement proper luma / luminance based values.
-        // This is simply taking the luminance weights derived from the
-        // OCIO configuration or the RGB to XYZ matrix and multiplying
-        // the above step approach by the luminance weights.
-        // EG:
-        cur_lum = vec3(dot(cur_col, luma_coeffs));
+            col += step(vec3(waveform_y - increment), cur_col) *
+                step(cur_col, vec3(waveform_y + increment)) * intensity;
 
-        col += step(vec3(ove_texcoord.y - increment), cur_lum) *
-            step(cur_lum, vec3(ove_texcoord.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;
+        }
     }
 
     gl_FragColor = vec4(col, 1.0);