Databases
StackOverflow2013
Postsdbo
POiOs OpenGL ES 2.0 adding textures with low opacity on device and on simulator
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POiOs OpenGL ES 2.0 adding textures with low opacity on device and on simulator
    primarykey
    data
    text
    <p>I have a problem with multiple drawing of textures in my program.</p> <p>Blending mode is</p> <pre><code>glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA); glBlendEquation(GL_FUNC_ADD); </code></pre> <p>The value of a-channel is passed into the shader from cpu-code.</p> <pre><code>precision highp float; uniform sampler2D tShape; uniform vec4 vColor; uniform float sOpacity; varying vec4 texCoords;\n" void main() { float a = texture2D(tShape, texCoords.xy).x * sOpacity; gl_FragColor = vec4(vColor.rgb, a); } </code></pre> <p>It's calculated previously with</p> <pre><code>O = pow(O, 1.3); </code></pre> <p>for the best visual effect.</p> <p>I draw with color (0; 0; 0) on the black transparent canvas (0;0;0;0), but with very low opacity:</p> <pre><code>0.03 -&gt; 0.01048 0.06 -&gt; 0.0258 0.09 -&gt; 0.0437 0.12 -&gt; 0.0635 ... </code></pre> <p>I expect, that maximal value of point's color will be (0;0;0;1) (black, no transparent) after multiple drawings as on the simulator: <img src="https://i.stack.imgur.com/kl8tZ.png" alt="enter image description here"></p> <p>but it isn't so on the device: <img src="https://i.stack.imgur.com/cijMd.png" alt="enter image description here"></p> <p>Do you have any ideas, why is it so?</p> <p><strong>UPDATE:</strong></p> <p>Also manual blending works incorrect too (and with difference from standard).</p> <pre><code>glBlendFunc(GL_ONE, GL_ZERO); </code></pre> <p>Fragment shader code:</p> <pre><code>#extension GL_EXT_shader_framebuffer_fetch : require precision highp float; uniform sampler2D tShape; uniform vec4 vColor; uniform float sOpacity; varying vec4 texCoords; void main() { float a = texture2D(tShape, texCoords.xy).x * sOpacity; gl_FragColor = vec4(vColor.rgb * a, a) + (gl_LastFragData[0] * (1.0 - a)); } </code></pre> <p>Result on the simulator: <img src="https://i.stack.imgur.com/vB6g8.png" alt="enter image description here"></p> <p>Result on the device: <img src="https://i.stack.imgur.com/ypNxD.png" alt="enter image description here"></p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USGeorge
    1. USGeorge
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POiOs OpenGL ES 2.0 adding textures with low opacity on device and on simulator
      1. USGeorge
      1. VTBountyStart
    2. VO
      singulars
      1. POiOs OpenGL ES 2.0 adding textures with low opacity on device and on simulator
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POiOs OpenGL ES 2.0 adding textures with low opacity on device and on simulator
      1. This table or related slice is empty.
      1. VTBountyClose
    1. COCan you post your whole fragment shader? It may be some rounding problem.
      singulars
      1. POiOs OpenGL ES 2.0 adding textures with low opacity on device and on simulator
      1. USTrax
    2. COUpdated (add fragment shader code)
      singulars
      1. POiOs OpenGL ES 2.0 adding textures with low opacity on device and on simulator
      1. USGeorge
    3. CORather strange, can you do manual blending and output 0 when certain threshold is met? Just to be sure the problem is not at the shader your input data. Output image should be black at certain areas.
      singulars
      1. POiOs OpenGL ES 2.0 adding textures with low opacity on device and on simulator
      1. USTrax
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload