Fog and Alpha for Layers — Handmade Hero — Episode Guide

2:07Recap and set the stage for the day

3:36handmade_world_mode.cpp: Set Volumes to not be Upright in UpdateAndRenderWorld

4:38Run the game and see the difference that makes

9:31handmade_render_group.h: Make GlobalAlpha in render_group a v4 and rename it to GlobalModulate

10:41Consider clearly distinguishing between colours that have premultiplied alpha and those that don't

12:39handmade_render_group.cpp: Introduce StoreColor and make PushBitmap, PushRect and Clear call it

14:25Blackboard: Hadamard Product

17:05handmade_render_group.h: Add tGlobalColor and GlobalColor to render_group to allow us to do a linear blend as well as a modulate

20:08handmade_render_group.cpp: Pass the Group to the StoreColor calls

21:11Blackboard: Fade vs Haze

22:22handmade_world_mode.cpp: Conditionally compute the tGlobalColor and GlobalColor for fade and haze in UpdateAndRenderWorld

25:11Run the game and note that we're not handling alpha multiplication correctly

26:04handmade_render.cpp: Stop DrawRectangle, DrawRectangleSlowly and DrawRectangleQuickly from premultiplying the alpha

27:20handmade_render_group.h: Rename Color to PremulColor where appropriate

29:41Run the game, see that our two renderers draw solid filled rectangles in different colours and investigate why this is the case

37:52handmade_render.cpp: Try not squaring the Color when modulating incoming Color in DrawRectangle

39:21handmade_render.cpp: Try Squaring the Color up front in DrawRectangle

42:37handmade_render.cpp: Try multiplying all the Colors by 255 again

43:25Run the game and see that that's almost exact

43:38Blackboard: Ensuring that we remain in the same colour space

47:23Debugger: Step into UpdateAndRenderWorld when CameraRelativeP.z > FadeTopStartZ and inspect the Color values

52:39handmade_opengl.cpp: Try rendering everything at 50% opacity

55:27Debugger: Step into OpenGLRectangle and inspect the Entry->PremulColor values

57:08handmade_render_group.h: Conditionally add DebugTag to render_group_entry_header and render_group if we are in HANDMADE_SLOW mode

1:00:10handmade_world_mode.cpp: Make UpdateAndRenderWorld set DebugTag to 1 if CameraRelativeP.z > FadeTopStartZ

1:01:06Debugger: Break into our BreakHere line in OpenGLRenderCommands

1:02:18handmade_world_mode.cpp: Negate the alpha of tGlobalColor for the fade

1:02:56Run the game and see that the fade is now correct

1:04:02Investigate why we are seeing nothing below our level

1:07:32handmade_world_mode.cpp: Enable the correct blending in UpdateAndRenderWorld

1:07:55handmade_world_mode.cpp: Initialise a BackgroundColor in UpdateAndRenderWorld and pass this to Clear and the GlobalColor for the lowest floors

1:08:55Run the game and see the haze happening

1:09:27Q&A

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1:09:27Q&A

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1:09:27Q&A

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1:10:03thesizik One thing you could try is having the center of the perspective projection be the player's position, so things on other levels line up straight

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1:10:03thesizik One thing you could try is having the center of the perspective projection be the player's position, so things on other levels line up straight

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1:10:03thesizik One thing you could try is having the center of the perspective projection be the player's position, so things on other levels line up straight

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1:10:29soysaucethekid The Hadamard transform seems like it can be used for a lot of things. What is it doing in handmade_world.cpp in the subtract function?

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1:10:29soysaucethekid The Hadamard transform seems like it can be used for a lot of things. What is it doing in handmade_world.cpp in the subtract function?

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1:10:29soysaucethekid The Hadamard transform seems like it can be used for a lot of things. What is it doing in handmade_world.cpp in the subtract function?

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1:10:56Blackboard: Hadamard Product ~= Diagonal Matrix

1:16:32cubercaleb For the record, a circle with an x would be the tensor product

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1:16:32cubercaleb For the record, a circle with an x would be the tensor product

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1:16:32cubercaleb For the record, a circle with an x would be the tensor product

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1:17:25jayp2 Would it be difficult to implement textured or just different fog colors, so you could make, for instance, vignetted fog?

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1:17:25jayp2 Would it be difficult to implement textured or just different fog colors, so you could make, for instance, vignetted fog?

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1:17:25jayp2 Would it be difficult to implement textured or just different fog colors, so you could make, for instance, vignetted fog?

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1:19:46shabiel How did you finally discover the gamma correction bug? What was the clue that made you say ah ha?

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1:19:46shabiel How did you finally discover the gamma correction bug? What was the clue that made you say ah ha?

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1:19:46shabiel How did you finally discover the gamma correction bug? What was the clue that made you say ah ha?

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1:21:05Wind it down

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1:21:05Wind it down

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1:21:05Wind it down

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