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add color dodge and multiply blending modes shaders, change tmp framebuffer to RGBA32F for better precision and fix the blending problem for the stroke not reaching full opacity

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omigamedev
2017-11-11 16:54:21 +00:00
parent 71f18cb292
commit fa4e67617b
4 changed files with 17 additions and 14 deletions
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13
engine/app_shaders.cpp
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@@ -94,13 +94,15 @@ void App::initShaders()
" sum += textureOffset(t, uv, ivec2(-1, 0));\n"
" sum += textureOffset(t, uv, ivec2(-1, 1));\n"
" sum += textureOffset(t, uv, ivec2( 0, -1));\n"
" sum += textureOffset(t, uv, ivec2( 0, 1));\n"
" sum += textureOffset(t, uv, ivec2( 1, -1));\n"
" sum += textureOffset(t, uv, ivec2( 1, 0));\n"
" sum += textureOffset(t, uv, ivec2( 1, 1));\n"
" return sum / vec4(9.0);\n"
"}\n"
"vec3 blend_colorDodge(vec4 base, vec4 stroke, float alpha_tot) { return mix(stroke.rgb, mix(base.rgb, base.rgb / (1.0 - stroke.rgb), stroke.a / alpha_tot), base.a / alpha_tot); }\n"
"vec3 blend_multiply(vec4 base, vec4 stroke, float alpha_tot) { return mix(stroke.rgb, mix(base.rgb, base.rgb * stroke.rgb, stroke.a / alpha_tot), base.a / alpha_tot); }\n"
"vec3 blend_normal(vec4 base, vec4 stroke, float alpha_tot) { return mix(base.rgb, stroke.rgb, stroke.a / alpha_tot); }\n"
"void main(){\n"
" mediump vec2 uv2 = gl_FragCoord.st / vec2(2048) * 20.0;\n"
" mediump vec4 base = texture(tex, uv.xy);\n"
@@ -108,9 +110,10 @@ void App::initShaders()
" mediump float stencil = pow(texture(tex_stencil, uv2).r, 8.0);\n"
" stroke.a = mask ? stroke.a * alpha * blur(tex_mask, uv.xy).r : stroke.a * alpha;\n"
" if (base.a == 0.0) { frag = stroke; return; }\n"
" mediump float contribution = (1.0 - base.a) * stroke.a;\n"
" mediump float alpha_tot = base.a + contribution;"
" mediump vec3 rgb = mix(base.rgb, stroke.rgb, (stroke.a / alpha_tot));\n"
" mediump vec3 rgb = blend_multiply(base, stroke, alpha_tot);\n"
" frag = vec4(rgb, (lock ? base.a : alpha_tot));\n"
"}\n";
@@ -267,12 +270,12 @@ void App::initShaders()
#else
" mediump vec4 bg = texture(tex_bg, uv2);\n"
#endif
" if (fg.a < 1.0/255.0) { frag = bg; return; }\n"
" mediump float contribution = max((1.0 - bg.a) * fg.a, 1.0/255.0) * stencil;\n"
" if (fg.a == 0.0) discard;\n"
" mediump float contribution = (1.0 - bg.a) * fg.a * stencil;\n"
" mediump float alpha_tot = bg.a + contribution;"
" mediump vec3 rgb = mix(bg.rgb, fg.rgb, fg.a / alpha_tot);\n"
" mediump vec4 frag_wet = vec4(rgb, mix(bg.a, max(bg.a, fg.a * stencil), fg.a));\n"
" mediump vec4 frag_dry = vec4(rgb, clamp(alpha_tot, 0.0, 1.0));\n"
" mediump vec4 frag_dry = vec4(rgb, alpha_tot);\n"
" frag = mix(frag_dry, frag_wet, wet);\n"
"}\n";

12
engine/canvas.cpp
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@@ -710,9 +710,9 @@ void ui::Canvas::resize(int width, int height)
m_height = height;
for (int i = 0; i < 6; i++)
{
m_tmp[i].create(width, height);
m_tex[i].create(width, height);
m_tex2[i].create(width, height);
m_tmp[i].create(width, height, -1, GL_RGBA32F);
m_tex[i].create(width, height, GL_RGBA32F);
m_tex2[i].create(width, height, GL_RGBA8);
}
for (auto& l : m_layers)
{
@@ -725,9 +725,9 @@ bool ui::Canvas::create(int width, int height)
m_height = height;
for (int i = 0; i < 6; i++)
{
m_tmp[i].create(width, height);
m_tex[i].create(width, height);
m_tex2[i].create(width, height); // TODO: destroy before recreating
m_tmp[i].create(width, height, -1, GL_RGBA32F);
m_tex[i].create(width, height, GL_RGBA32F);
m_tex2[i].create(width, height, GL_RGBA8); // TODO: destroy before recreating
}
m_sampler.create(GL_NEAREST);
m_sampler_brush.create();

4
engine/rtt.cpp
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@@ -40,7 +40,7 @@ void RTT::destroy()
// h = 0;
}
bool RTT::create(int width, int height, int tex/* = -1*/)
bool RTT::create(int width, int height, int tex/* = -1*/, GLint internal_format)
{
// Destroy any previously created object
destroy();
@@ -60,7 +60,7 @@ bool RTT::create(int width, int height, int tex/* = -1*/)
glBindTexture(GL_TEXTURE_2D, texID);
if (tex == -1)
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

2
engine/rtt.h
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@@ -15,7 +15,7 @@ public:
~RTT();
void destroy();
bool create(int width, int height, int tex = -1);
bool create(int width, int height, int tex = -1, GLint internal_format = GL_RGBA8);
bool recreate() { return create(w, h); }
void clear(glm::vec4 color = glm::vec4(0));
void readTextureData(uint8_t* buffer);