1 files changed, 69 insertions, 0 deletions
diff --git a/data/shader.vs b/data/shader.vs
new file mode 100755
index 0000000..8ce286e
--- /dev/null
+++ b/data/shader.vs
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+#version 140 // -*- mode: C -*-
+// Defines emitted by gridrectst::init_gl at load:
+// dimx, dimy:      Grid size of the screen array
+// dispx, dispy:    Grid-cell (font) size
+// vec4 colors[16]: Color palette; first non-bold, then bold
+#ifdef GRAPHICS
+// offset_texpos, offset_addcolor, offset_grayscale, offset_cf, offset_cbr:
+//   offsets of the corresponding graphicst arrays in data
+#endif
+
+uniform usamplerBuffer data;
+uniform samplerBuffer coords;
+uniform isamplerBuffer fontmap;
+
+uniform uint frame; // Counts up from 0
+
+in vec4 gl_Vertex;
+in int gl_VertexID;
+
+flat out vec4 frontColor;
+flat out vec4 backColor;
+smooth out vec2 texCoords;
+
+void main() {
+  int tile = gl_VertexID / 6;
+  int offset_tile = tile * 4;
+
+  int ch   = int(texelFetch(data, offset_tile).a);
+  int fg   = int(texelFetch(data, offset_tile+1).a);
+  int bg   = int(texelFetch(data, offset_tile+2).a);
+  int bold = clamp(int(texelFetch(data, offset_tile+3).a), 0, 1);
+
+#ifdef GRAPHICS
+  uint texpos = texelFetch(data, offset_texpos + offset_tile).a;
+  texpos += texelFetch(data, offset_texpos + offset_tile + 1).a * 256u;
+  texpos += texelFetch(data, offset_texpos + offset_tile + 2).a * 65536u;
+  texpos += texelFetch(data, offset_texpos + offset_tile + 3).a * 16777216u;
+  uint addcolor = texelFetch(data, offset_addcolor + offset_tile).a;
+  uint grayscale = texelFetch(data, offset_grayscale + offset_tile).a;
+  uint cf = texelFetch(data, offset_cf + offset_tile).a;
+  uint cbr = texelFetch(data, offset_cbr + offset_tile).a;
+
+
+  vec4 tex_square;
+  if (texpos != 0u && ch != 0) {
+    tex_square = texelFetch(coords, int(texpos));
+    if (grayscale != 0u) {
+      frontColor = colors[int(cf + cbr * 8u)];
+    } else if (addcolor != 0u) {
+      frontColor = colors[fg + bold * 8];
+    } else {
+      frontColor = vec4(1);
+    }
+  } else {
+    tex_square = texelFetch(coords, texelFetch(fontmap, ch).a);
+    frontColor  = colors[fg + bold * 8];
+  }
+#else
+  vec4 tex_square = texelFetch(coords, texelFetch(fontmap, ch).a);
+  frontColor  = colors[fg + bold * 8];
+#endif
+
+  vec2 coords[6] = vec2[](tex_square.sq, tex_square.tq, tex_square.tp,
+                          tex_square.sq, tex_square.tp, tex_square.sp);
+  texCoords = coords[gl_VertexID % 6];
+  
+  gl_Position = gl_Vertex;
+  backColor   = colors[bg];
+}