Learning_GTK4_tree/demos/gtk-demo/gtkshadertoy.c

527 lines
15 KiB
C

#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <epoxy/gl.h>
#include "gtkshadertoy.h"
const char *default_image_shader =
"void mainImage(out vec4 fragColor, in vec2 fragCoord) {\n"
" // Normalized pixel coordinates (from 0 to 1)\n"
" vec2 uv = fragCoord/iResolution.xy;\n"
"\n"
" // Time varying pixel color\n"
" vec3 col = 0.5 + 0.5*cos(iTime+uv.xyx+vec3(0,2,4));\n"
"\n"
" if (distance(iMouse.xy, fragCoord.xy) <= 10.0) {\n"
" col = vec3(0.0);\n"
" }\n"
"\n"
" // Output to screen\n"
" fragColor = vec4(col,1.0);\n"
"}\n";
const char *shadertoy_vertex_shader =
"#version 150 core\n"
"\n"
"uniform vec3 iResolution;\n"
"\n"
"in vec2 position;\n"
"out vec2 fragCoord;\n"
"\n"
"void main() {\n"
" gl_Position = vec4(position, 0.0, 1.0);\n"
"\n"
" // Convert from OpenGL coordinate system (with origin in center\n"
" // of screen) to Shadertoy/texture coordinate system (with origin\n"
" // in lower left corner)\n"
" fragCoord = (gl_Position.xy + vec2(1.0)) / vec2(2.0) * iResolution.xy;\n"
"}\n";
const char *fragment_prefix =
"#version 150 core\n"
"\n"
"uniform vec3 iResolution; // viewport resolution (in pixels)\n"
"uniform float iTime; // shader playback time (in seconds)\n"
"uniform float iTimeDelta; // render time (in seconds)\n"
"uniform int iFrame; // shader playback frame\n"
"uniform float iChannelTime[4]; // channel playback time (in seconds)\n"
"uniform vec3 iChannelResolution[4]; // channel resolution (in pixels)\n"
"uniform vec4 iMouse; // mouse pixel coords. xy: current (if MLB down), zw: click\n"
"uniform sampler2D iChannel0;\n"
"uniform sampler2D iChannel1;\n"
"uniform sampler2D iChannel2;\n"
"uniform sampler2D iChannel3;\n"
"uniform vec4 iDate; // (year, month, day, time in seconds)\n"
"uniform float iSampleRate; // sound sample rate (i.e., 44100)\n"
"\n"
"in vec2 fragCoord;\n"
"out vec4 vFragColor;\n";
// Fragment shader suffix
const char *fragment_suffix =
" void main() {\n"
" vec4 c;\n"
" mainImage(c, fragCoord);\n"
" vFragColor = c;\n"
" }\n";
typedef struct {
char *image_shader;
gboolean image_shader_dirty;
gboolean error_set;
/* Vertex buffers */
GLuint vao;
GLuint buffer;
/* Active program */
GLuint program;
/* Location of uniforms for program */
GLuint resolution_location;
GLuint time_location;
GLuint timedelta_location;
GLuint frame_location;
GLuint mouse_location;
/* Current uniform values */
float resolution[3];
float time;
float timedelta;
float mouse[4];
int frame;
/* Animation data */
gint64 first_frame_time;
gint64 first_frame;
guint tick;
} GtkShadertoyPrivate;
G_DEFINE_TYPE_WITH_PRIVATE (GtkShadertoy, gtk_shadertoy, GTK_TYPE_GL_AREA)
static gboolean gtk_shadertoy_render (GtkGLArea *area,
GdkGLContext *context);
static void gtk_shadertoy_reshape (GtkGLArea *area,
int width,
int height);
static void gtk_shadertoy_realize (GtkWidget *widget);
static void gtk_shadertoy_unrealize (GtkWidget *widget);
static gboolean gtk_shadertoy_tick (GtkWidget *widget,
GdkFrameClock *frame_clock,
gpointer user_data);
GtkWidget *
gtk_shadertoy_new (void)
{
return g_object_new (gtk_shadertoy_get_type (), NULL);
}
static void
drag_begin_cb (GtkGestureDrag *drag,
double x,
double y,
gpointer user_data)
{
GtkShadertoy *shadertoy = GTK_SHADERTOY (user_data);
GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
int height = gtk_widget_get_height (GTK_WIDGET (shadertoy));
int scale = gtk_widget_get_scale_factor (GTK_WIDGET (shadertoy));
priv->mouse[0] = x * scale;
priv->mouse[1] = (height - y) * scale;
priv->mouse[2] = priv->mouse[0];
priv->mouse[3] = priv->mouse[1];
}
static void
drag_update_cb (GtkGestureDrag *drag,
double dx,
double dy,
gpointer user_data)
{
GtkShadertoy *shadertoy = GTK_SHADERTOY (user_data);
GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
int width = gtk_widget_get_width (GTK_WIDGET (shadertoy));
int height = gtk_widget_get_height (GTK_WIDGET (shadertoy));
int scale = gtk_widget_get_scale_factor (GTK_WIDGET (shadertoy));
double x, y;
gtk_gesture_drag_get_start_point (drag, &x, &y);
x += dx;
y += dy;
if (x >= 0 && x < width &&
y >= 0 && y < height)
{
priv->mouse[0] = x * scale;
priv->mouse[1] = (height - y) * scale;
}
}
static void
drag_end_cb (GtkGestureDrag *drag,
double dx,
double dy,
gpointer user_data)
{
GtkShadertoy *shadertoy = GTK_SHADERTOY (user_data);
GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
priv->mouse[2] = -priv->mouse[2];
priv->mouse[3] = -priv->mouse[3];
}
static void
gtk_shadertoy_init (GtkShadertoy *shadertoy)
{
GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
GtkGesture *drag;
priv->image_shader = g_strdup (default_image_shader);
priv->tick = gtk_widget_add_tick_callback (GTK_WIDGET (shadertoy), gtk_shadertoy_tick, shadertoy, NULL);
drag = gtk_gesture_drag_new ();
gtk_widget_add_controller (GTK_WIDGET (shadertoy), GTK_EVENT_CONTROLLER (drag));
g_signal_connect (drag, "drag-begin", (GCallback)drag_begin_cb, shadertoy);
g_signal_connect (drag, "drag-update", (GCallback)drag_update_cb, shadertoy);
g_signal_connect (drag, "drag-end", (GCallback)drag_end_cb, shadertoy);
}
static void
gtk_shadertoy_finalize (GObject *obj)
{
GtkShadertoy *shadertoy = GTK_SHADERTOY (obj);
GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
gtk_widget_remove_tick_callback (GTK_WIDGET (shadertoy), priv->tick);
g_free (priv->image_shader);
G_OBJECT_CLASS (gtk_shadertoy_parent_class)->finalize (obj);
}
static void
gtk_shadertoy_class_init (GtkShadertoyClass *klass)
{
GTK_GL_AREA_CLASS (klass)->render = gtk_shadertoy_render;
GTK_GL_AREA_CLASS (klass)->resize = gtk_shadertoy_reshape;
GTK_WIDGET_CLASS (klass)->realize = gtk_shadertoy_realize;
GTK_WIDGET_CLASS (klass)->unrealize = gtk_shadertoy_unrealize;
G_OBJECT_CLASS (klass)->finalize = gtk_shadertoy_finalize;
}
/* new window size or exposure */
static void
gtk_shadertoy_reshape (GtkGLArea *area, int width, int height)
{
GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private ((GtkShadertoy *) area);
priv->resolution[0] = width;
priv->resolution[1] = height;
priv->resolution[2] = 1.0; /* screen aspect ratio */
/* Set the viewport */
glViewport (0, 0, (GLint) width, (GLint) height);
}
static GLuint
create_shader (int type,
const char *src,
GError **error)
{
GLuint shader;
int status;
shader = glCreateShader (type);
glShaderSource (shader, 1, &src, NULL);
glCompileShader (shader);
glGetShaderiv (shader, GL_COMPILE_STATUS, &status);
if (status == GL_FALSE)
{
int log_len;
char *buffer;
glGetShaderiv (shader, GL_INFO_LOG_LENGTH, &log_len);
buffer = g_malloc (log_len + 1);
glGetShaderInfoLog (shader, log_len, NULL, buffer);
g_set_error (error, GDK_GL_ERROR, GDK_GL_ERROR_COMPILATION_FAILED,
"Compile failure in %s shader:\n%s",
type == GL_VERTEX_SHADER ? "vertex" : "fragment",
buffer);
g_free (buffer);
glDeleteShader (shader);
return 0;
}
return shader;
}
static gboolean
init_shaders (GtkShadertoy *shadertoy,
const char *vertex_source,
const char *fragment_source,
GError **error)
{
GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
GLuint vertex, fragment;
GLuint program = 0;
int status;
gboolean res = TRUE;
vertex = create_shader (GL_VERTEX_SHADER, vertex_source, error);
if (vertex == 0)
return FALSE;
fragment = create_shader (GL_FRAGMENT_SHADER, fragment_source, error);
if (fragment == 0)
{
glDeleteShader (vertex);
return FALSE;
}
program = glCreateProgram ();
glAttachShader (program, vertex);
glAttachShader (program, fragment);
glLinkProgram (program);
glGetProgramiv (program, GL_LINK_STATUS, &status);
if (status == GL_FALSE)
{
int log_len;
char *buffer;
glGetProgramiv (program, GL_INFO_LOG_LENGTH, &log_len);
buffer = g_malloc (log_len + 1);
glGetProgramInfoLog (program, log_len, NULL, buffer);
g_set_error (error, GDK_GL_ERROR, GDK_GL_ERROR_LINK_FAILED,
"Linking failure:\n%s", buffer);
res = FALSE;
g_free (buffer);
glDeleteProgram (program);
goto out;
}
if (priv->program != 0)
glDeleteProgram (priv->program);
priv->program = program;
priv->resolution_location = glGetUniformLocation (program, "iResolution");
priv->time_location = glGetUniformLocation (program, "iTime");
priv->timedelta_location = glGetUniformLocation (program, "iTimeDelta");
priv->frame_location = glGetUniformLocation (program, "iFrame");
priv->mouse_location = glGetUniformLocation (program, "iMouse");
glDetachShader (program, vertex);
glDetachShader (program, fragment);
out:
/* These are now owned by the program and can be deleted */
glDeleteShader (vertex);
glDeleteShader (fragment);
return res;
}
static void
gtk_shadertoy_realize_shader (GtkShadertoy *shadertoy)
{
GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
char *fragment_shader;
GError *error = NULL;
fragment_shader = g_strconcat (fragment_prefix, priv->image_shader, fragment_suffix, NULL);
if (!init_shaders (shadertoy, shadertoy_vertex_shader, fragment_shader, &error))
{
priv->error_set = TRUE;
gtk_gl_area_set_error (GTK_GL_AREA (shadertoy), error);
g_error_free (error);
}
g_free (fragment_shader);
/* Start new shader at time zero */
priv->first_frame_time = 0;
priv->first_frame = 0;
priv->image_shader_dirty = FALSE;
}
static gboolean
gtk_shadertoy_render (GtkGLArea *area,
GdkGLContext *context)
{
GtkShadertoy *shadertoy = GTK_SHADERTOY (area);
GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
if (gtk_gl_area_get_error (area) != NULL)
return FALSE;
if (priv->image_shader_dirty)
gtk_shadertoy_realize_shader (shadertoy);
/* Clear the viewport */
glClearColor (0.0, 0.0, 0.0, 1.0);
glClear (GL_COLOR_BUFFER_BIT);
glUseProgram (priv->program);
/* Update uniforms */
if (priv->resolution_location != -1)
glUniform3fv (priv->resolution_location, 1, priv->resolution);
if (priv->time_location != -1)
glUniform1f (priv->time_location, priv->time);
if (priv->timedelta_location != -1)
glUniform1f (priv->timedelta_location, priv->timedelta);
if (priv->frame_location != -1)
glUniform1i (priv->frame_location, priv->frame);
if (priv->mouse_location != -1)
glUniform4fv (priv->mouse_location, 1, priv->mouse);
/* Use the vertices in our buffer */
glBindBuffer (GL_ARRAY_BUFFER, priv->buffer);
glEnableVertexAttribArray (0);
glVertexAttribPointer (0, 4, GL_FLOAT, GL_FALSE, 0, 0);
glDrawArrays (GL_TRIANGLES, 0, 6);
/* We finished using the buffers and program */
glDisableVertexAttribArray (0);
glBindBuffer (GL_ARRAY_BUFFER, 0);
glUseProgram (0);
/* Flush the contents of the pipeline */
glFlush ();
return TRUE;
}
const char *
gtk_shadertoy_get_image_shader (GtkShadertoy *shadertoy)
{
GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
return priv->image_shader;
}
void
gtk_shadertoy_set_image_shader (GtkShadertoy *shadertoy,
const char *shader)
{
GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
g_free (priv->image_shader);
priv->image_shader = g_strdup (shader);
/* Don't override error we didn't set it ourselves */
if (priv->error_set)
{
gtk_gl_area_set_error (GTK_GL_AREA (shadertoy), NULL);
priv->error_set = FALSE;
}
priv->image_shader_dirty = TRUE;
}
static void
gtk_shadertoy_realize (GtkWidget *widget)
{
GtkGLArea *glarea = GTK_GL_AREA (widget);
GtkShadertoy *shadertoy = GTK_SHADERTOY (widget);
GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
/* Draw two triangles across whole screen */
const GLfloat vertex_data[] = {
-1.0f, -1.0f, 0.f, 1.f,
-1.0f, 1.0f, 0.f, 1.f,
1.0f, 1.0f, 0.f, 1.f,
-1.0f, -1.0f, 0.f, 1.f,
1.0f, 1.0f, 0.f, 1.f,
1.0f, -1.0f, 0.f, 1.f,
};
GTK_WIDGET_CLASS (gtk_shadertoy_parent_class)->realize (widget);
gtk_gl_area_make_current (glarea);
if (gtk_gl_area_get_error (glarea) != NULL)
return;
glGenVertexArrays (1, &priv->vao);
glBindVertexArray (priv->vao);
glGenBuffers (1, &priv->buffer);
glBindBuffer (GL_ARRAY_BUFFER, priv->buffer);
glBufferData (GL_ARRAY_BUFFER, sizeof (vertex_data), vertex_data, GL_STATIC_DRAW);
glBindBuffer (GL_ARRAY_BUFFER, 0);
gtk_shadertoy_realize_shader (shadertoy);
}
static void
gtk_shadertoy_unrealize (GtkWidget *widget)
{
GtkGLArea *glarea = GTK_GL_AREA (widget);
GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private ((GtkShadertoy *) widget);
gtk_gl_area_make_current (glarea);
if (gtk_gl_area_get_error (glarea) == NULL)
{
if (priv->buffer != 0)
glDeleteBuffers (1, &priv->buffer);
if (priv->vao != 0)
glDeleteVertexArrays (1, &priv->vao);
if (priv->program != 0)
glDeleteProgram (priv->program);
}
GTK_WIDGET_CLASS (gtk_shadertoy_parent_class)->unrealize (widget);
}
static gboolean
gtk_shadertoy_tick (GtkWidget *widget,
GdkFrameClock *frame_clock,
gpointer user_data)
{
GtkShadertoy *shadertoy = GTK_SHADERTOY (widget);
GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
gint64 frame_time;
gint64 frame;
float previous_time;
frame = gdk_frame_clock_get_frame_counter (frame_clock);
frame_time = gdk_frame_clock_get_frame_time (frame_clock);
if (priv->first_frame_time == 0)
{
priv->first_frame_time = frame_time;
priv->first_frame = frame;
previous_time = 0;
}
else
previous_time = priv->time;
priv->time = (frame_time - priv->first_frame_time) / 1000000.0f;
priv->frame = frame - priv->first_frame;
priv->timedelta = priv->time - previous_time;
gtk_widget_queue_draw (widget);
return G_SOURCE_CONTINUE;
}