archive/blender-archive
Archived
1
1
Fork 0
Code Pull Requests Packages Activity

View3D: Atenuate banding artifacts on background gradient.

Browse Source 
Dithering the output color for 8bit precision framebuffer with bayer matrix.
On my tests the bayer matrux patterns are not noticeable at all.

Note that it also does that in opengl rendered mode which can be in a much
higher bitdepth. We can fix that if that's a problem in the future but I
doubt it will.
This commit is contained in:
Clément Foucault
2018-04-21 16:45:47 +02:00
parent 28a24db68a
commit c23f33ac9e
5 changed files with 26 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
source/blender/draw/intern/draw_view.c
View File

@@ -579,7 +579,7 @@ void DRW_draw_background(void)
gpuLoadIdentity();
gpuLoadProjectionMatrix(m);
immBindBuiltinProgram(GPU_SHADER_2D_SMOOTH_COLOR);
immBindBuiltinProgram(GPU_SHADER_2D_SMOOTH_COLOR_DITHER);
UI_GetThemeColor3ubv(TH_LOW_GRAD, col_lo);
UI_GetThemeColor3ubv(TH_HIGH_GRAD, col_hi);

1
source/blender/gpu/CMakeLists.txt
View File

@@ -143,6 +143,7 @@ data_to_c_simple(shaders/gpu_shader_2D_line_dashed_geom.glsl SRC)
data_to_c_simple(shaders/gpu_shader_2D_smooth_color_vert.glsl SRC)
data_to_c_simple(shaders/gpu_shader_2D_smooth_color_frag.glsl SRC)
data_to_c_simple(shaders/gpu_shader_2D_smooth_color_uniform_alpha_vert.glsl SRC)
data_to_c_simple(shaders/gpu_shader_2D_smooth_color_dithered_frag.glsl SRC)
data_to_c_simple(shaders/gpu_shader_2D_image_vert.glsl SRC)
data_to_c_simple(shaders/gpu_shader_2D_image_rect_vert.glsl SRC)
data_to_c_simple(shaders/gpu_shader_2D_image_multi_rect_vert.glsl SRC)

1
source/blender/gpu/GPU_shader.h
View File

@@ -112,6 +112,7 @@ typedef enum GPUBuiltinShader {
GPU_SHADER_2D_FLAT_COLOR,
GPU_SHADER_2D_SMOOTH_COLOR,
GPU_SHADER_2D_SMOOTH_COLOR_UNIFORM_ALPHA,
GPU_SHADER_2D_SMOOTH_COLOR_DITHER,
GPU_SHADER_2D_IMAGE,
GPU_SHADER_2D_IMAGE_COLOR,
GPU_SHADER_2D_IMAGE_ALPHA_COLOR,

3
source/blender/gpu/intern/gpu_shader.c
View File

@@ -66,6 +66,7 @@ extern char datatoc_gpu_shader_2D_flat_color_vert_glsl[];
extern char datatoc_gpu_shader_2D_smooth_color_uniform_alpha_vert_glsl[];
extern char datatoc_gpu_shader_2D_smooth_color_vert_glsl[];
extern char datatoc_gpu_shader_2D_smooth_color_frag_glsl[];
extern char datatoc_gpu_shader_2D_smooth_color_dithered_frag_glsl[];
extern char datatoc_gpu_shader_2D_image_vert_glsl[];
extern char datatoc_gpu_shader_2D_image_rect_vert_glsl[];
extern char datatoc_gpu_shader_2D_image_multi_rect_vert_glsl[];
@@ -702,6 +703,8 @@ GPUShader *GPU_shader_get_builtin_shader(GPUBuiltinShader shader)
datatoc_gpu_shader_2D_smooth_color_frag_glsl },
[GPU_SHADER_2D_SMOOTH_COLOR_UNIFORM_ALPHA] = { datatoc_gpu_shader_2D_smooth_color_uniform_alpha_vert_glsl,
datatoc_gpu_shader_2D_smooth_color_frag_glsl },
[GPU_SHADER_2D_SMOOTH_COLOR_DITHER] = { datatoc_gpu_shader_2D_smooth_color_vert_glsl,
datatoc_gpu_shader_2D_smooth_color_dithered_frag_glsl },
[GPU_SHADER_2D_IMAGE_LINEAR_TO_SRGB] = { datatoc_gpu_shader_2D_image_vert_glsl,
datatoc_gpu_shader_image_linear_frag_glsl },
[GPU_SHADER_2D_IMAGE] = { datatoc_gpu_shader_2D_image_vert_glsl,

20
source/blender/gpu/shaders/gpu_shader_2D_smooth_color_dithered_frag.glsl Normal file
View File

@@ -0,0 +1,20 @@
noperspective in vec4 finalColor;
out vec4 fragColor;
/* 4x4 bayer matrix prepared for 8bit UNORM precision error. */
#define P(x) (((x + 0.5) * (1.0 / 16.0) - 0.5) * (1.0 / 255.0))
const vec4 dither_mat4x4[4] = vec4[4](
vec4( P(0.0), P(8.0), P(2.0), P(10.0)),
vec4(P(12.0), P(4.0), P(14.0), P(6.0)),
vec4( P(3.0), P(11.0), P(1.0), P(9.0)),
vec4(P(15.0), P(7.0), P(13.0), P(5.0))
);
void main()
{
ivec2 tx1 = ivec2(gl_FragCoord.xy) % 4;
ivec2 tx2 = ivec2(gl_FragCoord.xy) % 2;
float dither_noise = dither_mat4x4[tx1.x][tx1.y];
fragColor = finalColor + dither_noise;
}