lolengine
/
lol
mirror of https://github.com/lolengine/lol
1
0
Fork 0
Code Issues 0 Releases 0 Wiki Activity
Browse Source

tutorial: simplify the Mandelbrot viewing shader in the hope that it will 

work on i915 cards.
legacy
Sam Hocevar sam 13 years ago
parent
0a669f9c49
commit
222401ad97
1 changed files with 128 additions and 128 deletions
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. +128
    -128
      test/tutorial/tut03.cpp

+ 128
- 128
test/tutorial/tut03.cpp View File

@@ -51,11 +51,13 @@ public:
Fractal(ivec2 const &size)
{
/* Ensure texture size is a multiple of 16 for better aligned
* data access. Store the dimensions of a texel for our shader. */
* data access. Store the dimensions of a texel for our shader,
* as well as the half-size of the screen. */
m_size = size;
m_size.x = (m_size.x + 15) & ~15;
m_size.y = (m_size.y + 15) & ~15;
m_texel_settings = vec4(vec2(1.0, 1.0) / (vec2)m_size, m_size);
m_texel_settings = vec4(vec2(1.0, 1.0) / (vec2)m_size,
vec2(0.5, 0.5) * (vec2)m_size);

/* Window size decides the world aspect ratio. For instance, 640×480
* will be mapped to (-0.66,-0.5) - (0.66,0.5). */
@@ -71,6 +73,8 @@ public:
m_window2world = 0.5 / m_window_size.x;
m_texel2world = (vec2)m_window_size / (vec2)m_size * m_window2world;

m_oldmouse = ivec2(0, 0);

m_pixels = new u8vec4[m_size.x * m_size.y];
m_tmppixels = new u8vec4[m_size.x / 2 * m_size.y / 2];
m_frame = -1;
@@ -89,6 +93,7 @@ public:
m_center = -0.75;
m_zoom_speed = 0.0;
#endif
m_translate = 0;
m_radius = 5.0;
m_ready = false;

@@ -179,6 +184,21 @@ public:

ivec3 buttons = Input::GetMouseButtons();
#if !defined __CELLOS_LV2__
if (buttons[1])
{
if (clicked[1])
m_oldmouse = mousepos;
m_translate = ScreenToWorldOffset(m_oldmouse)
- ScreenToWorldOffset(mousepos);
m_oldmouse = mousepos;
}
else if (m_translate != 0.0)
{
m_translate *= pow(2.0, -deltams * 0.005);
if (m_translate.norm() / m_radius < 1e-4)
m_translate = 0.0;
}

if ((buttons[0] || buttons[2]) && mousepos.x != -1)
{
double zoom = buttons[0] ? -0.0005 : 0.0005;
@@ -194,7 +214,7 @@ public:
}
#endif

if (m_zoom_speed)
if (m_zoom_speed || m_translate != 0.0)
{
f64cmplx oldcenter = m_center;
double oldradius = m_radius;
@@ -211,6 +231,7 @@ public:
}
m_radius *= zoom;
#if !defined __CELLOS_LV2__
m_center += m_translate;
m_center = (m_center - worldmouse) * zoom + worldmouse;
worldmouse = m_center + ScreenToWorldOffset(mousepos);
#endif
@@ -231,9 +252,6 @@ public:
m_deltascale[prev_frame] = 1.0;
}

if (buttons[1])
m_dirty[0] = m_dirty[1] = m_dirty[2] = m_dirty[3] = 2;

/* Transformation from current frame to current frame is always
* identity. */
m_zoom_settings[m_frame][0] = 0.0f;
@@ -251,6 +269,13 @@ public:
m_zoom_settings[cur_index][2] = m_zoom_settings[prev_index][2] * m_deltascale[cur_index];
}

/* Precompute texture offset change instead of doing it in GLSL */
for (int i = 0; i < 4; i++)
{
m_zoom_settings[i][0] += 0.5 * (1.0 - m_zoom_settings[i][2]);
m_zoom_settings[i][1] -= 0.5 * (1.0 - m_zoom_settings[i][2]);
}

#if !defined __native_client__
char buf[128];
sprintf(buf, "center: %+16.14f%+16.14fi", m_center.x, m_center.y);
@@ -363,19 +388,44 @@ public:
"precision highp float;"
#endif
""
#if defined HAVE_GLES_2X
"varying vec2 pass_TexCoord;"
#endif
"attribute vec2 in_TexCoord;"
"attribute vec2 in_Vertex;"
"uniform mat4 u_ZoomSettings;"
"uniform vec4 u_TexelSize;"
""
"attribute vec2 a_TexCoord;"
"attribute vec2 a_Vertex;"
""
"varying vec2 A0, A1, A2, A3;"
"varying vec2 B0, B1, B2, B3;"
""
"void main(void)"
"{"
" gl_Position = vec4(in_Vertex, 0.0, 1.0);"
#if defined HAVE_GLES_2X
" pass_TexCoord = in_TexCoord;"
#else
" gl_TexCoord[0] = vec4(in_TexCoord, 0.0, 0.0);"
#endif
" gl_Position = vec4(a_Vertex, 0.0, 1.0);"
/* Center point in [-.5,.5], apply zoom and translation
* transformation, and go back to texture coordinates
* in [0,1]. That's the ideal point we would like to
* compute the value for. Then add or remove half the
* size of a texel: the distance from this new point to
* the final point will be our error. */
" A0 = a_TexCoord * u_ZoomSettings[0][2]"
" + vec2(u_ZoomSettings[0][0], -u_ZoomSettings[0][1])"
" + 0.5 * u_TexelSize.xy;"
" A1 = a_TexCoord * u_ZoomSettings[1][2]"
" + vec2(u_ZoomSettings[1][0], -u_ZoomSettings[1][1])"
" + -0.5 * u_TexelSize.xy;"
" A2 = a_TexCoord * u_ZoomSettings[2][2]"
" + vec2(u_ZoomSettings[2][0], -u_ZoomSettings[2][1])"
" + vec2(0.5, -0.5) * u_TexelSize.xy;"
" A3 = a_TexCoord * u_ZoomSettings[3][2]"
" + vec2(u_ZoomSettings[3][0], -u_ZoomSettings[3][1])"
" + vec2(-0.5, 0.5) * u_TexelSize.xy;"
/* Precompute the multiple of one texel where our ideal
* point lies. The fragment shader will call floor() on
* this value. We add or remove a slight offset to avoid
* rounding issues at the image's edges. */
" B0 = (A0 * u_TexelSize.zw + vec2(-0.015625, -0.015625));"
" B1 = (A1 * u_TexelSize.zw + vec2( 0.015625, 0.015625));"
" B2 = (A2 * u_TexelSize.zw + vec2(-0.015625, 0.015625));"
" B3 = (A3 * u_TexelSize.zw + vec2( 0.015625, -0.015625));"
"}",

#if !defined HAVE_GLES_2X
@@ -384,18 +434,17 @@ public:
"precision highp float;"
#endif
""
#if defined HAVE_GLES_2X
"varying vec2 pass_TexCoord;"
#endif
"uniform vec4 in_TexelSize;"
"uniform mat4 in_ZoomSettings;"
"uniform vec4 u_TexelSize;"
"uniform sampler2D in_Texture;"
""
"varying vec2 A0, A1, A2, A3;"
"varying vec2 B0, B1, B2, B3;"
""
"vec2 v05 = vec2(0.5, 0.5);"
""
"float mylen(vec2 p)"
"{"
" p *= in_TexelSize.zw;" /* Correct for aspect ratio */
" p *= u_TexelSize.zw;" /* Correct for aspect ratio */
//" return 0.001 + abs(p.x) + abs(p.y);"
//" return 0.1 + length(p);"
" vec2 q = p * p;"
@@ -404,95 +453,46 @@ public:
""
/* Get the coordinate of the nearest point in slice 0 in xy,
* and the squared distance to that point in z.
* p is in normalised [0,1] texture coordinates.
* return value has the 0.25 Y scaling. */
"vec3 nearest0(vec2 p)"
"vec3 nearest0()"
"{"
/* Step 1: center point in [-.5,.5], apply zoom and
* translation transformation, and go back to texture
* coordinates in [0,1]. That's the ideal point we
* would like to compute the value for. */
" p -= vec2(0.5, 0.5);"
" p *= in_ZoomSettings[0][2];"
" p += vec2(in_ZoomSettings[0][0], -in_ZoomSettings[0][1]);"
" p += vec2(0.5, 0.5);"
/* Step 2: find out the (rounded) texel coordinates in
* the half-resolution slice. We use an offset of 15/32
* instead of 1/2 to avoid rounding issues at edges. */
" vec2 q = p + 0.46875 * in_TexelSize.xy;"
" q = in_TexelSize.xy"
" * (1.0 + 2.0 * floor(q * 0.5 * in_TexelSize.zw));"
/* Step 3: go back to full-resolution texel coordinates
* so that we know the error between the pixel we get
* and the pixel we wanted. */
" vec2 r = q - 0.5 * in_TexelSize.xy;"
" vec2 t = step(abs(q - v05), v05);"
" float l = t.x * t.y / mylen(r - p);"
/* Step 4: return final texel coordinates and
* corresponding error value. */
" return vec3(q * vec2(1.0, 0.25), l);"
" vec2 r = u_TexelSize.xy * (1.0 + 2.0 * floor(B0));"
" vec2 t = step(abs(r - v05), v05);"
" float l = t.x * t.y / mylen(r - A0);"
" return vec3(r * vec2(1.0, 0.25), l);"
"}"
""
"vec3 nearest1(vec2 p)"
"vec3 nearest1()"
"{"
" p -= vec2(0.5, 0.5);"
" p *= in_ZoomSettings[1][2];"
" p += vec2(in_ZoomSettings[1][0], -in_ZoomSettings[1][1]);"
" p += vec2(0.5, 0.5);"
" vec2 q = p + -0.46875 * in_TexelSize.xy;"
" q = in_TexelSize.xy"
" * (1.0 + 2.0 * floor(q * 0.5 * in_TexelSize.zw));"
" vec2 r = q - -0.5 * in_TexelSize.xy;"
""
" vec2 t = step(abs(q - v05), v05);"
" float l = t.x * t.y / mylen(r - p);"
" return vec3(q * vec2(1.0, 0.25) + vec2(0.0, 0.25), l);"
" vec2 r = u_TexelSize.xy * (1.0 + 2.0 * floor(B1));"
" vec2 t = step(abs(r - v05), v05);"
" float l = t.x * t.y / mylen(r - A1);"
" return vec3(r * vec2(1.0, 0.25) + vec2(0.0, 0.25), l);"
"}"
""
"vec3 nearest2(vec2 p)"
"vec3 nearest2()"
"{"
" p -= vec2(0.5, 0.5);"
" p *= in_ZoomSettings[2][2];"
" p += vec2(in_ZoomSettings[2][0], -in_ZoomSettings[2][1]);"
" p += vec2(0.5, 0.5);"
" vec2 q = p + vec2(0.46875, -0.46875) * in_TexelSize.xy;"
" q = in_TexelSize.xy"
" * (1.0 + 2.0 * floor(q * 0.5 * in_TexelSize.zw));"
" vec2 r = q - vec2(0.5, -0.5) * in_TexelSize.xy;"
""
" vec2 t = step(abs(q - v05), v05);"
" float l = t.x * t.y / mylen(r - p);"
" return vec3(q * vec2(1.0, 0.25) + vec2(0.0, 0.50), l);"
" vec2 r = u_TexelSize.xy * (1.0 + 2.0 * floor(B2));"
" vec2 t = step(abs(r - v05), v05);"
" float l = t.x * t.y / mylen(r - A2);"
" return vec3(r * vec2(1.0, 0.25) + vec2(0.0, 0.50), l);"
"}"
""
"vec3 nearest3(vec2 p)"
"vec3 nearest3()"
"{"
" p -= vec2(0.5, 0.5);"
" p *= in_ZoomSettings[3][2];"
" p += vec2(in_ZoomSettings[3][0], -in_ZoomSettings[3][1]);"
" p += vec2(0.5, 0.5);"
" vec2 q = p + vec2(-0.46875, 0.46875) * in_TexelSize.xy;"
" q = in_TexelSize.xy"
" * (1.0 + 2.0 * floor(q * 0.5 * in_TexelSize.zw));"
" vec2 r = q - vec2(-0.5, 0.5) * in_TexelSize.xy;"
""
" vec2 t = step(abs(q - v05), v05);"
" float l = t.x * t.y / mylen(r - p);"
" return vec3(q * vec2(1.0, 0.25) + vec2(0.0, 0.75), l);"
" vec2 r = u_TexelSize.xy * (1.0 + 2.0 * floor(B3));"
" vec2 t = step(abs(r - v05), v05);"
" float l = t.x * t.y / mylen(r - A3);"
" return vec3(r * vec2(1.0, 0.25) + vec2(0.0, 0.75), l);"
"}"
""
"void main(void)"
"{"
#if defined HAVE_GLES_2X
" vec2 coord = pass_TexCoord;"
#else
" vec2 coord = gl_TexCoord[0].xy;"
#endif
/* Get a pixel coordinate from each slice */
" vec3 k0 = nearest0(coord);"
" vec3 k1 = nearest1(coord);"
" vec3 k2 = nearest2(coord);"
" vec3 k3 = nearest3(coord);"
" vec3 k0 = nearest0();"
" vec3 k1 = nearest1();"
" vec3 k2 = nearest2();"
" vec3 k3 = nearest3();"
/* Get the nearest pixel */
" float t01 = step(k0.z, k1.z);"
" k0 = mix(k0, k1, t01);"
@@ -511,69 +511,69 @@ public:
"}"
#else
"void main(float4 in_Position : POSITION,"
" float2 in_TexCoord : TEXCOORD0,"
" float2 a_TexCoord : TEXCOORD0,"
" out float4 out_Position : POSITION,"
" out float2 out_TexCoord : TEXCOORD0)"
"{"
" out_TexCoord = in_TexCoord;"
" out_TexCoord = a_TexCoord;"
" out_Position = in_Position;"
"}",

"float3 nearest0(float2 p, float4 in_TexelSize)"
"float3 nearest0(float2 p, float4 u_TexelSize)"
"{"
" float2 q = p + 0.5 * in_TexelSize.xy;"
" q -= fmod(q, 2.0 * in_TexelSize.xy);"
" q += 0.5 * in_TexelSize.xy;"
" float2 q = p + 0.5 * u_TexelSize.xy;"
" q -= fmod(q, 2.0 * u_TexelSize.xy);"
" q += 0.5 * u_TexelSize.xy;"
" return float3(q * float2(1.0, 0.25),"
" length(q - p));"
"}"
""
"float3 nearest1(float2 p, float4 in_TexelSize)"
"float3 nearest1(float2 p, float4 u_TexelSize)"
"{"
" float2 q = p - 0.5 * in_TexelSize.xy;"
" q -= fmod(q, 2.0 * in_TexelSize.xy);"
" q += 1.5 * in_TexelSize.xy;"
" float2 q = p - 0.5 * u_TexelSize.xy;"
" q -= fmod(q, 2.0 * u_TexelSize.xy);"
" q += 1.5 * u_TexelSize.xy;"
" return float3(q * float2(1.0, 0.25) + float2(0.0, 0.25),"
" length(q - p));"
"}"
""
"float3 nearest2(float2 p, float4 in_TexelSize)"
"float3 nearest2(float2 p, float4 u_TexelSize)"
"{"
" float2 q = p + float2(0.5, -0.5) * in_TexelSize.xy;"
" q -= fmod(q, 2.0 * in_TexelSize.xy);"
" q += float2(0.5, 1.5) * in_TexelSize.xy;"
" float2 q = p + float2(0.5, -0.5) * u_TexelSize.xy;"
" q -= fmod(q, 2.0 * u_TexelSize.xy);"
" q += float2(0.5, 1.5) * u_TexelSize.xy;"
" return float3(q * float2(1.0, 0.25) + float2(0.0, 0.50),"
" length(q - p));"
"}"
""
"float3 nearest3(float2 p, float4 in_TexelSize)"
"float3 nearest3(float2 p, float4 u_TexelSize)"
"{"
" float2 q = p + float2(-0.5, 0.5) * in_TexelSize.xy;"
" q -= fmod(q, 2.0 * in_TexelSize.xy);"
" q += float2(1.5, 0.5) * in_TexelSize.xy;"
" float2 q = p + float2(-0.5, 0.5) * u_TexelSize.xy;"
" q -= fmod(q, 2.0 * u_TexelSize.xy);"
" q += float2(1.5, 0.5) * u_TexelSize.xy;"
" return float3(q * float2(1.0, 0.25) + float2(0.0, 0.75),"
" length(q - p));"
"}"
""
"void main(float2 in_TexCoord : TEXCOORD0,"
" uniform float4 in_TexelSize,"
"void main(float2 a_TexCoord : TEXCOORD0,"
" uniform float4 u_TexelSize,"
" uniform sampler2D in_Texture,"
" out float4 out_FragColor : COLOR)"
"{"
" float2 coord = in_TexCoord.xy;"
" coord -= 0.1 * in_TexelSize.xy;"
" float4 p0 = tex2D(in_Texture, nearest0(coord, in_TexelSize).xy);"
" float4 p1 = tex2D(in_Texture, nearest1(coord, in_TexelSize).xy);"
" float4 p2 = tex2D(in_Texture, nearest2(coord, in_TexelSize).xy);"
" float4 p3 = tex2D(in_Texture, nearest3(coord, in_TexelSize).xy);"
" float2 coord = a_TexCoord.xy;"
" coord -= 0.1 * u_TexelSize.xy;"
" float4 p0 = tex2D(in_Texture, nearest0(coord, u_TexelSize).xy);"
" float4 p1 = tex2D(in_Texture, nearest1(coord, u_TexelSize).xy);"
" float4 p2 = tex2D(in_Texture, nearest2(coord, u_TexelSize).xy);"
" float4 p3 = tex2D(in_Texture, nearest3(coord, u_TexelSize).xy);"
" out_FragColor = 0.25 * (p0 + p1 + p2 + p3);"
"}"
#endif
);
m_vertexattrib = m_shader->GetAttribLocation("in_Vertex");
m_texattrib = m_shader->GetAttribLocation("in_TexCoord");
m_texeluni = m_shader->GetUniformLocation("in_TexelSize");
m_zoomuni = m_shader->GetUniformLocation("in_ZoomSettings");
m_vertexattrib = m_shader->GetAttribLocation("a_Vertex");
m_texattrib = m_shader->GetAttribLocation("a_TexCoord");
m_texeluni = m_shader->GetUniformLocation("u_TexelSize");
m_zoomuni = m_shader->GetUniformLocation("u_ZoomSettings");
m_ready = true;

#if !defined __CELLOS_LV2__ && !defined __ANDROID__
@@ -659,7 +659,7 @@ private:
static int const MAX_ITERATIONS = 170;
static int const PALETTE_STEP = 32;

ivec2 m_size, m_window_size;
ivec2 m_size, m_window_size, m_oldmouse;
double m_window2world;
f64vec2 m_texel2world;
u8vec4 *m_pixels, *m_tmppixels, *m_palette;
@@ -673,7 +673,7 @@ private:
int m_frame, m_dirty[4];
bool m_ready;

f64cmplx m_center;
f64cmplx m_center, m_translate;
double m_zoom_speed, m_radius;
vec4 m_texel_settings;
mat4 m_zoom_settings;


Write Preview
Loading…
Cancel
Save