00:13 < bridge> @heinrich5991 Firefox has the nice graphic. How do they generate it? Is there a script? 00:22 < bridge> chillerdragon: gay 00:24 < bridge> https://stackoverflow.com/a/7553878/870079 00:25 < bridge> hmm this answer suggests we might only need to copy the `.DS_Store` from dmg created on macOS 11:48 < bridge> i got an espresso machine yesterday 11:48 < bridge> im up at 4 now 13:17 < bridge> why sdl alpha blending weird? 13:17 < bridge> first is how it looks pre-blending 13:17 < bridge> second is how it should look 13:17 < bridge> third is how it actually looks. it’s dark in the middle 13:17 < bridge> https://media.discordapp.net/attachments/806786136474910730/1163035155460538438/image.png?ex=653e1be5&is=652ba6e5&hm=9391b99eab6fe560d1e5a7320d5bd2d893505ca08e22087f44238ab6472a14e0& 13:17 < bridge> 13:17 < bridge> https://media.discordapp.net/attachments/806786136474910730/1163035774866960464/image.png?ex=653e1c78&is=652ba778&hm=687c67ab991a3c51f491b87a6ec934a3b192c2b38a66cd564b1e729e1e277685& 13:17 < bridge> 13:17 < bridge> https://media.discordapp.net/attachments/806786136474910730/1163033900138905600/image.png?ex=653e1ab9&is=652ba5b9&hm=ad9ddd60a00e588417d63617e2419fa5f54aa71d25950ac5497c67c379d52e29& 13:18 < bridge> why sdl alpha blending weird? 13:18 < bridge> first is how it looks pre-blending 13:18 < bridge> second is how it should look 13:18 < bridge> third is how it actually looks. it’s dark in the middle 13:18 < bridge> https://media.discordapp.net/attachments/806786136474910730/1163035155460538438/image.png 13:18 < bridge> https://media.discordapp.net/attachments/806786136474910730/1163035774866960464/image.png 13:18 < bridge> https://media.discordapp.net/attachments/806786136474910730/1163033900138905600/image.png 13:18 < bridge> gross link watermarks 13:28 < bridge> sdl? 13:30 < bridge> yes 13:30 < bridge> sdl 13:30 < bridge> the sequel 13:30 < bridge> ? 13:30 < bridge> sdl = sdl2 library? 13:32 < bridge> yes lmfao 13:32 < bridge> yeah sry but u give 0 information 13:32 < bridge> 13:32 < bridge> so i assume you mean the SDL renderer? 13:32 < bridge> what blend mode do you use? 13:33 < bridge> blend mode 13:33 < bridge> sdl renderer or surface irrrelevant 13:34 < bridge> so which blend mode is blend mode? 13:34 < bridge> one minus alpha? 13:34 < bridge> SDL_BLENDMODE_BLEND 13:34 < bridge> so one minus alpha 13:35 < bridge> looks like the mask is alpha premutliplied and shouldnt be 13:37 < bridge> i guess SDL_BLENDMODE_ADD is the one that emulates that then 13:37 < bridge> nah 13:37 < bridge> or SDL_BLENDMODE_MOD 13:37 < bridge> if u premultiply your own vertex color 13:38 < bridge> try all the blend modes until it works 13:38 < bridge> i did already 13:38 < bridge> they are all not proper 13:38 < bridge> if u get your request right: u want to have the alpha values of texture1 be multiplied with the text that u add 13:39 < bridge> remade surf and specified rgba32 non premultiplied and still wacky 13:39 < bridge> u have to do that in one render call 13:39 < bridge> not in 2 13:42 < bridge> what render call 13:43 < bridge> let's get the thing right first: 13:43 < bridge> you want the second text to be partially transparent at the outer edges right? 13:43 < bridge> 13:43 < bridge> and texture1 defines how much transparent it should be 13:43 < bridge> yes 13:43 < bridge> tbh i don't know if u can do smth like that with the SDL renderer 13:43 < bridge> it seems very primitive 13:44 < bridge> u'd need to sample over texture 1 and multiple the alpha of this texture with the vertices that you render, when you create the second text 13:44 < bridge> i just want to blend the gradient texture over top of the source texture using a normal blending mode 13:44 < bridge> but i think there is a problem with their math since doing that creates dark spots near the middle 13:45 < bridge> it should be pretty simple 13:45 < bridge> no, that looks correct to me tbh 13:45 < bridge> it's not really trivial imo 13:45 < bridge> fwiw black is just for show 13:45 < bridge> when drawing the gradient im actually using transparent 13:45 < bridge> yeah but you need the information of that texture in a different render call 13:45 < bridge> im using surfaces 13:45 < bridge> render call = i want to draw these vertices 13:46 < bridge> yea we are not in gpu world rn 13:46 < bridge> let me read what they are in sdl2 renderer 13:46 < bridge> fwiw 13:46 < bridge> sdl2 renderer is gpu 13:46 < bridge> used with textures 13:46 < bridge> surfaces is cpu rendering 13:46 < bridge> texture = hardware backed surface 13:47 < bridge> well it's more abstract 13:47 < bridge> but using the accelerated init 13:47 < bridge> that's what it is 13:47 < bridge> ah so you have full control over all pixels? 13:47 < bridge> yes 13:47 < bridge> i don't wanna do it myself but i could 13:47 < bridge> i guess u have to do it your own then 13:47 < bridge> i just wonder why their math is weird 13:47 < bridge> shouldn't be hard u know 13:47 < bridge> https://cdn.discordapp.com/attachments/293493549758939136/1163080820211322940/image.png?ex=653e466c&is=652bd16c&hm=6bef2f10b63adb325000ff64309771d869397e7feec8b63e73cfd949c6e4269c& 13:48 < bridge> so u simply want to overwrite the pixels instead of making them transparent 13:48 < bridge> well that's one solution yes 13:48 < bridge> no no 13:48 < bridge> it's like they're using color key internally or smthm 13:48 < bridge> instead of mathing on the alphas 13:49 < bridge> well one minus source alpha is your blend mode 13:49 < bridge> what you want, but they don't offer, is using the dst alpha value 13:49 < bridge> the alpha values written by texture 1 13:50 < bridge> that is so ass 13:51 < bridge> u can do custom blending modes 13:51 < bridge> i guess ill check that out 13:53 < bridge> ```cpp 13:53 < bridge> SDL_ComposeCustomBlendMode(SDL_BLENDFACTOR_ONE, 13:53 < bridge> SDL_BLENDFACTOR_DST_ALPHA, 13:53 < bridge> SDL_BLENDOPERATION_ADD, 13:53 < bridge> SDL_BLENDFACTOR_ONE, 13:53 < bridge> SDL_BLENDFACTOR_DST_ALPHA, 13:53 < bridge> SDL_BLENDOPERATION_ADD); 13:53 < bridge> ``` 13:53 < bridge> ugg 13:53 < bridge> https://cdn.discordapp.com/attachments/293493549758939136/1163082197511716905/image.png?ex=653e47b4&is=652bd2b4&hm=61b7d7e8018e6b878fca5ffe5e43e760f0a04340cae5e93e642da82475363450& 13:54 < bridge> it should work as you expect with alpha blending and a properly generated mask. I bet your issue is the mask 13:55 < bridge> tried mask and it didn't help 13:55 < bridge> by mask I mean the texture2 that has the gradient 13:55 < bridge> you think that im making the gradient wrong? 13:55 < bridge> i dont think this renderer has support for multiple texture sampling 13:56 < bridge> so u cannot really mask it 13:56 < bridge> as u imagine it 13:56 < bridge> I bet it is a gradient from rgba(0,0,0,0) to rgba(0,0,255,255) which is not what you want 13:56 < bridge> you want rgba(0,0,255,0) to rgba(0,0,255,255) 13:56 < bridge> which is not-premultiplied alpha 13:56 < bridge> im not doing color blending only alpha, 13:56 < bridge> from blue to transparent 13:57 < bridge> ```cpp 13:57 < bridge> void RenderLinearGradient(SDL_Surface *surf, 13:57 < bridge> const SDL_Rect *rect, 13:57 < bridge> const SDL_Color *color1, 13:57 < bridge> const SDL_Color *color2, 13:57 < bridge> bool orientation) 13:57 < bridge> { 13:57 < bridge> SDL_Rect walking_rect = SDL_Rect(*rect); 13:57 < bridge> 13:57 < bridge> auto *offset = orientation ? &walking_rect.x : &walking_rect.y; 13:57 < bridge> auto *pos = orientation ? &walking_rect.w : &walking_rect.h; 13:57 < bridge> 13:57 < bridge> auto starting_offset = *offset; 13:57 < bridge> auto starting_pos = *pos; 13:57 < bridge> *pos = 1; 13:57 < bridge> for (; *offset < starting_offset + starting_pos; (*offset)++) { 13:57 < bridge> float fraction = (float(*offset - starting_offset) / float(starting_pos)); 13:57 < bridge> SDL_FillRect(surf, &walking_rect, Interpolate(surf->format, color2, color1, fraction)); 13:57 < bridge> } 13:57 < bridge> } 13:57 < bridge> ``` 13:57 < bridge> define "transparent" htats the issue 13:57 < bridge> this my fn 13:57 < bridge> 0,0,0,0 13:57 < bridge> try blue with alpha 0 13:57 < bridge> 0,0,1,0 or smth 13:58 < bridge> @k2d222 what you want is 13:58 < bridge> 13:58 < bridge> render text1 13:58 < bridge> render text2 13:58 < bridge> put gradient over text2? 13:58 < bridge> yes it's not really mask it's overlya 13:58 < bridge> yes it's not really mask it's overlay 13:59 < bridge> or text generally 13:59 < bridge> if that's all the same text 13:59 < bridge> cal them surfs ur hurting my brain 13:59 < bridge> im like what text and then i remember u speak of texture 13:59 < bridge> xd 13:59 < bridge> no 13:59 < bridge> i mean text this time 14:00 < bridge> ou 14:00 < bridge> it's a bit wierd to call it surface, that generally refers to smth els 14:00 < bridge> it's a bit wierd to call it surface, that generally refers to smth else 14:00 < bridge> not in 2d 14:00 < bridge> @mpft before applying the gradient 14:00 < bridge> 14:00 < bridge> do u render the text in one go? 14:00 < bridge> yeah 14:00 < bridge> ok 14:00 < bridge> here's it with transparent blue btw 14:00 < bridge> https://cdn.discordapp.com/attachments/293493549758939136/1163084043911438397/image.png?ex=653e496d&is=652bd46d&hm=d513c13f33f9a451bec9165eef2cffce616e1eea26aa8c19040c7ad92dce296f& 14:00 < bridge> ok 14:00 < bridge> what i expected 14:00 < bridge> and then u want to put the gradient over it 14:01 < bridge> yep 14:01 < bridge> ok 14:02 < bridge> so basically what u actually want is 14:02 < bridge> 14:02 < bridge> render the text on a seperate texture, that has no background color 14:02 < bridge> bcs one problem is that the background color is used during blending too 14:02 < bridge> which makes everything darker not only the text 14:02 < bridge> or 14:03 < bridge> u want a pure alpha texture. and use blue manually 14:04 < bridge> ok or let's do it differently 14:04 < bridge> why is this black in first place? 14:04 < bridge> ~ 14:04 < bridge> did u do that manually by hand? 14:04 < bridge> or how should i understand that 14:05 < bridge> i replaced the transparent in my gradient fn invoc w black 14:05 < bridge> but it looks identical when i just turn off blending 14:05 < bridge> ok 14:05 < bridge> but that sounds wrong to me already. 14:05 < bridge> 14:05 < bridge> it should be white 14:06 < bridge> when using 0,0,0,0? 14:06 < bridge> ok tbf it depends on the blend mode 14:06 < bridge> can u just post the gradient here? 14:07 < bridge> the texture for it 14:07 < bridge> it's dynamically generated 14:07 < bridge> i'd have to dump 14:07 < bridge> i c 14:07 < bridge> this is recreated 14:07 < bridge> with same math 14:08 < bridge> yeah, so u don't aim to make text transparent 14:08 < bridge> but simply overwrite it 14:08 < bridge> yep 14:08 < bridge> oh wow sorry i didn't realize that's what u were asking 14:08 < bridge> that's also a pretty good idea 14:08 < bridge> it's ok. i was very confused here too 14:08 < bridge> then bg can be whatever and not be a color 14:08 < bridge> no, for this renderer your approach is better 14:09 < bridge> maybe faster and easier 14:09 < bridge> but not better 14:09 < bridge> if i want to have transparency effects in the ui like i usually do 14:09 < bridge> my approach requires to sample from 2 textures at once 14:09 < bridge> from the text-texture and the gradient-texture 14:09 < bridge> that's the problem 14:09 < bridge> i dunno if u can do it without shaders 😄 14:09 < bridge> ok i mean u can do anything 14:09 < bridge> since it's on the CPU 14:09 < bridge> SDL_ComposeCustomBlendMode lets you use source and destination 14:10 < bridge> src color mode, src alpha mode, src blend op, dst color mode, dst alpha mode, dst blend op 14:10 < bridge> that's my understanding is it correct? 14:10 < bridge> https://cdn.discordapp.com/attachments/293493549758939136/1163086498929848321/image.png?ex=653e4bb6&is=652bd6b6&hm=7829960169105963651c826f5012c0a9980e672f9eb1bbf9cbc612ba60523fc0& 14:10 < bridge> sorta but no borders on gradient 14:10 < bridge> just the inner 14:11 < bridge> mh then normal blending should work indeed 14:11 < bridge> eys 14:11 < bridge> yea 14:11 < bridge> so why black 14:11 < bridge> >_> 14:11 < bridge> but 14:11 < bridge> to be sure, dump the gradient 14:11 < bridge> k 14:11 < bridge> that's the only way to be sure 14:11 < bridge> time to import sdl2_image 14:11 < bridge> :pepeW: 14:11 < bridge> all your stuff does not happen on the GPU? 14:11 < bridge> all cpu 14:11 < bridge> would be much easier XD 14:12 < bridge> not really for arbitrary rendering 14:12 < bridge> well at least not without shaders 😂 14:12 < bridge> yea 14:12 < bridge> lmfao 14:13 < bridge> oh my GOD i don't even have it 14:13 < bridge> https://cdn.discordapp.com/attachments/293493549758939136/1163087343801081896/image.png?ex=653e4c7f&is=652bd77f&hm=d3644643eee026bf563218199ac5be079dfe47a61741a683a0c29b489078c4c9& 14:14 < bridge> sample a few valuess along the x axis should be sufficient 14:15 < bridge> no it's rly 2 fn calls and i already have the thing set up now 14:15 < bridge> thanks msys 14:17 < bridge> https://cdn.discordapp.com/attachments/293493549758939136/1163088153721192448/test.png?ex=653e4d40&is=652bd840&hm=76efae3b13291bca6ccbbaac0f8a0c5d3c9f45a6dbaf8335cd04a7e1b7f62e0d& 14:17 < bridge> there 14:17 < bridge> dumped 14:17 < bridge> yeah ok 14:18 < bridge> you were right from the start then i guess 14:18 < bridge> i hate it when i'm right 14:20 < bridge> what u could try is dumping before gradient and after 14:20 < bridge> i blit that right on top of this 14:20 < bridge> https://cdn.discordapp.com/attachments/293493549758939136/1163089085259337768/image.png?ex=653e4e1f&is=652bd91f&hm=796a60b956dd6e6b9eeb268ba89c65466710911af710b5fd5b15667fa0963e2b& 14:20 < bridge> i could imagine one reason why it's wrong 14:21 < bridge> u overwriting the final alpha values with values close to 0 14:21 < bridge> 14:21 < bridge> and at some point it uses that texture to render it to the screen 14:21 < bridge> unfortunately i don't think that's possible cuz the gradient texture gets blitted to the button + the button gets blitted directly to the window's surface 14:22 < bridge> that's the only alpha stuff happening 14:22 < bridge> and i'm only touching the values in the gradient fn 14:22 < bridge> I insist that the img has the issue of premult alpha, and that produces the black result that you have as expected. the region with alpha = 0 must have the correct rgb values. 14:22 < bridge> where would this premultiplication be happening 14:22 < bridge> my interpolation fn is unbiased 14:22 < bridge> ```cpp 14:22 < bridge> uint32_t Interpolate(SDL_PixelFormat *format, 14:22 < bridge> const SDL_Color *color1, 14:22 < bridge> const SDL_Color *color2, 14:22 < bridge> float fraction) 14:22 < bridge> { 14:22 < bridge> return SDL_MapRGBA(format, 14:22 < bridge> static_cast((color1->r - color2->r) * fraction + color2->r), 14:23 < bridge> static_cast((color1->g - color2->g) * fraction + color2->g), 14:23 < bridge> static_cast((color1->b - color2->b) * fraction + color2->b), 14:23 < bridge> static_cast((color1->a - color2->a) * fraction + color2->a)); 14:23 < bridge> } 14:23 < bridge> ``` 14:23 < bridge> i mean it would make sense, but i wonder when this multiplication should happen 14:23 < bridge> do you have experience with sdl2 renderer? 14:23 < bridge> https://wiki.libsdl.org/SDL2/SDL_BlendMode > the described blend mode function indicates that it expects non-premult alpha 14:23 < bridge> yes 14:24 < bridge> but like, he dumped the texture 14:24 < bridge> yet the image gradiend dumped has premult alpha 14:24 < bridge> that might be png encoder 14:24 < bridge> i mean, "premult alpha" not really, it's just a normal gradient from opaque blue to black transparent 14:25 < bridge> to me the color looks right 14:25 < bridge> in gimp 14:26 < bridge> @mpft can u write to the pixels directly? 14:26 < bridge> how low level 14:26 < bridge> like set all alpha to 1 after your whole calculation 14:26 < bridge> of the surface 14:26 < bridge> https://cdn.discordapp.com/attachments/293493549758939136/1163090578238611487/image.png?ex=653e4f83&is=652bda83&hm=fd4f27b9a891c8482d24fd2a21ba1db1f91c44336ca16ef2ec7984afef29eede& 14:27 < bridge> top=ewan btm=me 14:27 < bridge> yeahmm 14:27 < bridge> it does fade to black 14:27 < bridge> ah i see 14:27 < bridge> i could but that's exactly how it displays with alpha blending off 14:27 < bridge> i will try blending opaque blue to transparent blue 14:27 < bridge> @k2d222 is right actually 14:27 < bridge> i mean gradienting 14:27 < bridge> https://cdn.discordapp.com/attachments/293493549758939136/1163090858862727248/image.png?ex=653e4fc5&is=652bdac5&hm=e53463840663a13245d6d79ca0d98416c2e2ad2175b2e377950e5363aae7c039& 14:27 < bridge> u know 14:27 < bridge> i mean yea that's what im doing 14:28 < bridge> 0,0,00 14:28 < bridge> 0,0,0,0 14:28 < bridge> yeah but i disabled alpha layer 14:28 < bridge> ah yeah 14:28 < bridge> can u simply use the blue all the time 14:28 < bridge> only make alpha go 0 14:28 < bridge> it does work but it's not desirable 14:28 < bridge> https://cdn.discordapp.com/attachments/293493549758939136/1163091098537836606/image.png?ex=653e4fff&is=652bdaff&hm=2fe583920c57a15bf9e01a15732d0ec16e365fea873860124c06a997c55b6609& 14:28 < bridge> u dont want any color gradiation 14:29 < bridge> what do you dislike about it? 14:29 < bridge> what is that not what u want?? 14:30 < bridge> i am just wondering how it is that pdn can create the exact correct gradient from scratch when i use 0,0,0,0 as the second color 14:30 < bridge> but now that i look at my mockup gradient i see that it's the same blue and all that changes is the alpha. so pdn must be doing something 'smart' under the hood and changing my black transparent to something more appropriate 14:30 < bridge> cool i guess 14:30 < bridge> since that's what i was comparing it against i thought black was not the issue 14:30 < bridge> it does exist yes 14:31 < bridge> some programs do that 14:31 < bridge> would have been nice to know 30 mins ago 14:31 < bridge> damn 14:31 < bridge> they un-premultiply alpha and copy neighbor alpha in pixels that have alpha=0 14:32 < bridge> it's a bit hacky but allows correct antialiasing at opaque-alpha edges in some cases 14:32 < bridge> yeah 14:32 < bridge> quite hacky 14:32 < bridge> definitely not expected 14:32 < bridge> unity does that iirc 14:33 < bridge> what is pdn? 14:33 < bridge> paint.net 14:34 < bridge> why do they do this? 14:34 < bridge> 14:34 < bridge> do they dislike loosing color values? 14:35 < bridge> how does that even help restore the original color if alpha = 0 14:36 < bridge> to avoid interpolation artefacts at sharp opaque->transparent edges, but I think that was in fact not what was happening for @mpft 14:36 < bridge> it’s the gradient tool, it may just be for this exact scenario 14:36 < bridge> I read about it recently leme see if i find the article for you 14:37 < bridge> ok but do we speak about pre multiplied textures, with a blend mode that is addative? 14:40 < bridge> check out my awesome hue interpolation 14:40 < bridge> https://cdn.discordapp.com/attachments/293493549758939136/1163094039218888724/image.png?ex=653e52bc&is=652bddbc&hm=29a833fd6381ef574301159194da3938b473848982111fdf0287daf0b6c35f71& 14:41 < bridge> even tho my rgb interpolation does it just fine 14:41 < bridge> https://cdn.discordapp.com/attachments/293493549758939136/1163094238158925954/image.png?ex=653e52eb&is=652bddeb&hm=8f8e0a857eabeea9d25e8cb476c2cfb3f25ff7dfdc173fae6bae6f032a4dce28& 14:41 < bridge> i wanted to try it 14:41 < bridge> it's not high tech enough 14:42 < bridge> heh, apparently I remembered it incorrectly, still good to know about, here's the source 14:42 < bridge> https://youtu.be/d6tp43wZqps?si=rUkq6fjBGbiI19G6&t=627 14:43 < bridge> good video to watch overall btw 14:43 < bridge> i like my buttons 14:43 < bridge> https://cdn.discordapp.com/attachments/293493549758939136/1163094913408311370/image.png?ex=653e538c&is=652bde8c&hm=dd2137603e387dbd56c0d46103998103f51cfbae8cf9e4402c49cd464a2ae4ec& 14:44 < bridge> ah 14:44 < bridge> ddnet has the same problem btw 14:45 < bridge> in ddnet we call it "dialate" 14:45 < bridge> pre multiplied textures have one obvious problem 14:45 < bridge> dilate* 14:45 < bridge> loss of precision? 14:45 < bridge> they remove accuracy if u use them with u8 color components 14:45 < bridge> yes 14:45 < bridge> precision is better word^^ 14:45 < bridge> ty 😄 14:46 < bridge> I never know the difference between precision and accuracy, but precision exists in french 14:46 < bridge> I never know the difference between precision and accuracy, but precision exists in french and not accuracy 15:01 < bridge> same thing 15:02 < bridge> dump it again 15:02 < bridge> watcha workin on 15:02 < bridge> looks futuristic xd 15:04 < bridge> idk im just making stuff 15:04 < bridge> ive been helping this guy do some sdl stuff and he needed a gui 15:04 < bridge> and i always knew a gui in sdl would be very easy to do i just never had to do it 15:04 < bridge> so im doing it 15:04 < bridge> but not for him just for fun 15:07 < bridge> ddnet gui system is very logical but not readable in code. It's a nightmare to come back to some gui that you made months ago and try to get what's going on 15:07 < bridge> ddnet gui system is filling rects xd 15:08 < bridge> it's immediate mode nonsense 15:08 < bridge> yes. good rects 15:08 < bridge> ruthless on the cpu 15:08 < bridge> egui does similar, but is still nicer to use imo 15:08 < bridge> egui sux 15:08 < bridge> qt win 15:08 < bridge> immediate is good 15:08 < bridge> qt vloat 15:08 < bridge> for a game ui maybe 15:08 < bridge> qt bloat 15:08 < bridge> yeah 15:08 < bridge> not if it's installed on your system as a shared lib lol 15:09 < bridge> stuff like React is cleaner imo for GUIs 15:09 < bridge> ew 15:09 < bridge> webb 15:09 < bridge> i mean the idea 15:09 < bridge> not javascript xd 15:09 < bridge> I've never seen a frontend in C++ that isn't a mess 15:10 < bridge> that is probably bcs they don't give enough shit about performance xd 15:11 < bridge>