Fix for zero size textures and 1-source alpha blending

+vis/draw.m

@@ -36,6 +36,8 @@
       glBlendFunc(GL.DST_ALPHA, GL.ONE_MINUS_DST_ALPHA);
     case {'src' 'source'}
       glBlendFunc(GL.SRC_ALPHA, GL.ONE_MINUS_SRC_ALPHA);
+    case {'1-src' '1-source'}
+      glBlendFunc(GL.ONE_MINUS_SRC_ALPHA, GL.SRC_ALPHA);
   end
   %glColorMask(layer.colourMask(1), layer.colourMask(2),...
   %  layer.colourMask(3), layer.colourMask(4));

+vis/loadLayerTextures.m

@@ -2,37 +2,12 @@
 %VIS.LOADLAYERTEXTURES Summary of this function goes here
 %   Detailed explanation goes here
 
-global GL;
-
 gltex = glGenTextures(numel(layers)); % make the OGL texture names
 for ii = 1:numel(layers)
 %   rgba = uint8(round(255*layers(ii).rgba));
 %   rgba = permute(rgba(end:-1:1,:,:), [3 2 1]);
 
-  w = layers(ii).rgbaSize(1);
-  h = layers(ii).rgbaSize(2);
-  glBindTexture(GL.TEXTURE_2D, gltex(ii)); % bind our texture name
-  glTexImage2D(GL.TEXTURE_2D, 0, GL.RGBA, w, h, 0,...
-    GL.RGBA, GL.UNSIGNED_BYTE, layers(ii).rgba);
-  switch layers(ii).interpolation
-    case 'linear'
-      glTexParameteri(GL.TEXTURE_2D, GL.TEXTURE_MAG_FILTER, GL.LINEAR);
-      glTexParameteri(GL.TEXTURE_2D, GL.TEXTURE_MIN_FILTER, GL.LINEAR);
-    case 'nearest'
-      glTexParameteri(GL.TEXTURE_2D, GL.TEXTURE_MAG_FILTER, GL.NEAREST);
-      glTexParameteri(GL.TEXTURE_2D, GL.TEXTURE_MIN_FILTER, GL.LINEAR);
-    otherwise
-      error('Invalid interpolation method ''%s''', layers(ii).interpolation);
-  end
-
-  if layers(ii).isPeriodic
-    glTexParameteri(GL.TEXTURE_2D, GL.TEXTURE_WRAP_S, GL.REPEAT);
-    glTexParameteri(GL.TEXTURE_2D, GL.TEXTURE_WRAP_T, GL.REPEAT);
-  else
-    glTexParameteri(GL.TEXTURE_2D, GL.TEXTURE_WRAP_S, GL.CLAMP_TO_BORDER);
-    glTexParameteri(GL.TEXTURE_2D, GL.TEXTURE_WRAP_T, GL.CLAMP_TO_BORDER);
-    glTexParameterfv(GL.TEXTURE_2D, GL.TEXTURE_BORDER_COLOR, single([0 0 0 0]));
-  end
+  vis.reloadLayerTexture(layers(ii));
 end
 
 end

+vis/reloadLayerTexture.m

@@ -27,7 +27,11 @@ function reloadLayerTexture(layer, gltex)
 else
   glTexParameteri(GL.TEXTURE_2D, GL.TEXTURE_WRAP_S, GL.CLAMP_TO_BORDER);
   glTexParameteri(GL.TEXTURE_2D, GL.TEXTURE_WRAP_T, GL.CLAMP_TO_BORDER);
-  glTexParameterfv(GL.TEXTURE_2D, GL.TEXTURE_BORDER_COLOR, single([0 0 0 0]));
+  if any(strcmp(layer.blending, {'1-src' '1-source'}))
+    glTexParameterfv(GL.TEXTURE_2D, GL.TEXTURE_BORDER_COLOR, single([0 0 0 1]));
+  else
+    glTexParameterfv(GL.TEXTURE_2D, GL.TEXTURE_BORDER_COLOR, single([0 0 0 0]));
+  end
 end
 
 end

+vis/slimshady.vert

@@ -33,8 +33,10 @@ void main()
     /*mat4 view = rot3(yax, posRad.x)*rot3(zax, posRad.y)*rot3(xax, viewRad);*/
     gl_Position = projection*view*model*vec4(vertexPos.xyz, 1.0f);
 
-    vec2 texScale = vec2(180.0/texSize.x, 180.0/texSize.y);
-    vec2 texTrans = vec2(-texOffset.x/texSize.x, -texOffset.y/texSize.y);
+    vec2 safeTexSize = vec2(texSize.x != 0.0f ? texSize.x : 1e-10, 
+      texSize.y != 0.0f ? texSize.y : 1e-10);
+    vec2 texScale = vec2(180.0/safeTexSize.x, 180.0/safeTexSize.y);
+    vec2 texTrans = vec2(-texOffset.x/safeTexSize.x, -texOffset.y/safeTexSize.y);
     mat3 uvTrans = trans2(vec2(0.5) + texTrans)*scale2(texScale)*
       rot2(texAngle*pi/180)*scale2(vec2(2.0, 1.0))*trans2(vec2(-0.5));
     UV = (uvTrans*vec3(vertexUV.xy, 1.0f)).xy;