diff --git a/resources/examples/raylib/raylib_shaders_mandelbrot_set.c3 b/resources/examples/raylib/raylib_shaders_mandelbrot_set.c3 new file mode 100644 index 000000000..39630e90a --- /dev/null +++ b/resources/examples/raylib/raylib_shaders_mandelbrot_set.c3 @@ -0,0 +1,271 @@ +module shader_mandelbrot_set; +import raylib55, std::math; +/******************************************************************************************* +* +* raylib [shaders] example - mandelbrot set +* +* Example complexity rating: [★★★☆] 3/4 +* +* NOTE: This example requires raylib OpenGL 3.3 or ES2 versions for shaders support, +* OpenGL 1.1 does not support shaders, recompile raylib to OpenGL 3.3 version +* +* NOTE: Shaders used in this example are #version 330 (OpenGL 3.3) +* +* Example originally created with raylib 5.6, last time updated with raylib 5.6 +* +* Example contributed by Jordi Santonja (@JordSant) +* Based on previous work by Josh Colclough (@joshcol9232) +* converted to C3 by Christoffer Lerno +* +* Example licensed under an unmodified zlib/libpng license, which is an OSI-certified, +* BSD-like license that allows static linking with closed source software +* +* Copyright (c) 2025 Jordi Santonja (@JordSant) +* +********************************************************************************************/ + +const GLSL_VERSION = 330; + +// A few good interesting places +const float[<3>][6] POINTS_OF_INTEREST = +{ + { -1.76826775f, -0.00422996283f, 28435.9238f }, + { 0.322004497f, -0.0357099883f, 56499.7266f }, + { -0.748880744f, -0.0562955774f, 9237.59082f }, + { -1.78385007f, -0.0156200649f, 14599.5283f }, + { -0.0985441282f, -0.924688697f, 26259.8535f }, + { 0.317785531f, -0.0322612226f, 29297.9258f }, +}; + +const int SCREEN_WIDTH = 800; +const int SCREEN_HEIGHT = 450; +const float ZOOM_SPEED = 1.01f; +const float OFFSET_SPEED_MUL = 2.0f; + +const float STARTING_ZOOM = 0.6f; +const float[<2>] STARTING_OFFSET = { -0.5f, 0.0f }; + +fn int main() +{ + // Initialization + //-------------------------------------------------------------------------------------- + rl::init_window(SCREEN_WIDTH, SCREEN_HEIGHT, "raylib [shaders] example - mandelbrot set"); + + // Load mandelbrot set shader + // NOTE: Defining 0 (NULL) for vertex shader forces usage of internal default vertex shader + RLShader shader = rl::load_shader_from_memory(null, SHADER_CODE); + + // Create a RenderTexture2D to be used for render to texture + RLRenderTexture2D target = rl::load_render_texture(rl::get_screen_width(), rl::get_screen_height()); + + // Offset and zoom to draw the mandelbrot set at. (centered on screen and default size) + float[<2>] offset = STARTING_OFFSET; + float zoom = STARTING_ZOOM; + // Depending on the zoom the mximum number of iterations must be adapted to get more detail as we zzoom in + // The solution is not perfect, so a control has been added to increase/decrease the number of iterations with UP/DOWN keys + int max_iterations = 333; + float max_iterations_multiplier = 166.5f; + + // Get variable (uniform) locations on the shader to connect with the program + // NOTE: If uniform variable could not be found in the shader, function returns -1 + int zoom_loc = shader.get_location("zoom"); + int offset_loc = shader.get_location("offset"); + int max_iterations_loc = shader.get_location("maxIterations"); + + // Upload the shader uniform values! + shader.set_value(zoom_loc, &zoom, FLOAT); + shader.set_value(offset_loc, &offset, VEC2); + shader.set_value(max_iterations_loc, &max_iterations, INT); + + bool show_controls = true; // Show controls + + rl::set_target_fps(60); // Set our game to run at 60 frames-per-second + //-------------------------------------------------------------------------------------- + + // Main game loop + while (!rl::window_should_close()) // Detect window close button or ESC key + { + // Update + //---------------------------------------------------------------------------------- + bool update_shader = false; + + // Press [1 - 6] to reset c to a point of interest + if (rl::is_key_pressed(ONE) || rl::is_key_pressed(TWO) || rl::is_key_pressed(THREE) + || rl::is_key_pressed(FOUR) || rl::is_key_pressed(FIVE) || rl::is_key_pressed(SIX)) + { + int interest_index = 0; + switch + { + case rl::is_key_pressed(ONE): interest_index = 0; + case rl::is_key_pressed(TWO): interest_index = 1; + case rl::is_key_pressed(THREE): interest_index = 2; + case rl::is_key_pressed(FOUR): interest_index = 3; + case rl::is_key_pressed(FIVE): interest_index = 4; + case rl::is_key_pressed(SIX): interest_index = 5; + } + offset = POINTS_OF_INTEREST[interest_index].xy; + zoom = POINTS_OF_INTEREST[interest_index].z; + update_shader = true; + } + + // If "R" is pressed, reset zoom and offset + if (rl::is_key_pressed(R)) + { + offset = STARTING_OFFSET; + zoom = STARTING_ZOOM; + update_shader = true; + } + + switch + { + case rl::is_key_pressed(F1): + show_controls = !show_controls; // Toggle whether or not to show controls + // Change number of max iterations with UP and DOWN keys + // WARNING: Increasing the number of max iterations greatly impacts performance + case rl::is_key_pressed(UP): + max_iterations_multiplier *= 1.4f; + update_shader = true; + case rl::is_key_pressed(DOWN): + max_iterations_multiplier /= 1.4f; + update_shader = true; + + } + + // If either left or right button is pressed, zoom in/out + if (rl::is_mouse_button_down(LEFT) || rl::is_mouse_button_down(RIGHT)) + { + // Change zoom. If Mouse left -> zoom in. Mouse right -> zoom out + zoom *= rl::is_mouse_button_down(LEFT) ? ZOOM_SPEED : (1.0f / ZOOM_SPEED); + + RLVector2 mouse_pos = rl::get_mouse_position(); + // Find the velocity at which to change the camera. Take the distance of the mouse + // From the center of the screen as the direction, and adjust magnitude based on the current zoom + RLVector2 offset_velocity = ((mouse_pos / { SCREEN_WIDTH, SCREEN_HEIGHT }) - 0.5) * OFFSET_SPEED_MUL / zoom; + + // Apply move velocity to camera + offset += rl::get_frame_time() * offset_velocity; + + update_shader = true; + } + + // In case a parameter has been changed, update the shader values + if (update_shader) + { + // As we zoom in, increase the number of max iterations to get more detail + // Aproximate formula, but it works-ish + max_iterations = (int)(math::sqrt(2.0f * math::sqrt(math::abs(1.0f - math::sqrt(37.5f * zoom)))) * max_iterations_multiplier); + + // Update the shader uniform values! + shader.set_value(zoom_loc, &zoom, FLOAT); + shader.set_value(offset_loc, &offset, VEC2); + shader.set_value(max_iterations_loc, &max_iterations, INT); + } + //---------------------------------------------------------------------------------- + + // Draw + //---------------------------------------------------------------------------------- + // Using a render texture to draw Mandelbrot set + rl::begin_texture_mode(target); // Enable drawing to texture + rl::clear_background(rl::BLACK); // Clear the render texture + + // Draw a rectangle in shader mode to be used as shader canvas + // NOTE: Rectangle uses font white character texture coordinates, + // So shader can not be applied here directly because input vertexTexCoord + // Do not represent full screen coordinates (space where want to apply shader) + rl::draw_rectangle(0, 0, rl::get_screen_width(), rl::get_screen_height(), rl::BLACK); + rl::end_texture_mode(); + + rl::begin_drawing(); + rl::clear_background(rl::BLACK); // Clear screen background + + // Draw the saved texture and rendered mandelbrot set with shader + // NOTE: We do not invert texture on Y, already considered inside shader + rl::begin_shader_mode(shader); + // WARNING: If FLAG_WINDOW_HIGHDPI is enabled, HighDPI monitor scaling should be considered + // When rendering the RenderTexture2D to fit in the HighDPI scaled Window + rl::draw_texture_ex(target.texture, { 0.0f, 0.0f }, 0.0f, 1.0f, rl::WHITE); + rl::end_shader_mode(); + + if (show_controls) + { + rl::draw_text("Press Mouse buttons right/left to zoom in/out and move", 10, 15, 10, rl::RAYWHITE); + rl::draw_text("Press F1 to toggle these controls", 10, 30, 10, rl::RAYWHITE); + rl::draw_text("Press [1 - 6] to change point of interest", 10, 45, 10, rl::RAYWHITE); + rl::draw_text("Press UP | DOWN to change number of iterations", 10, 60, 10, rl::RAYWHITE); + rl::draw_text("Press R to recenter the camera", 10, 75, 10, rl::RAYWHITE); + } + rl::end_drawing(); + //---------------------------------------------------------------------------------- + } + + // De-Initialization + //-------------------------------------------------------------------------------------- + rl::unload_shader(shader); // Unload shader + rl::unload_render_texture(target); // Unload render texture + + rl::close_window(); // Close window and OpenGL context + //-------------------------------------------------------------------------------------- + + return 0; +} + +const ZString SHADER_CODE = ` +#version 330 + +#define PI 3.1415926535897932384626433832795 + +// Input vertex attributes (from vertex shader) +in vec2 fragTexCoord; +in vec4 fragColor; + +// Output fragment color +out vec4 finalColor; + +uniform vec2 offset; // Offset of the scale +uniform float zoom; // Zoom of the scale +uniform int maxIterations; // Max iterations per pixel + +const float max = 4.0; // We consider infinite as 4.0: if a point reaches a distance of 4.0 it will escape to infinity +const float max2 = max*max; // Square of max to avoid computing square root + +void main() +{ + // The pixel coordinates are scaled so they are on the mandelbrot scale + // NOTE: fragTexCoord already comes as normalized screen coordinates but offset must be normalized before scaling and zoom + vec2 c = vec2((fragTexCoord.x - 0.5)*2.5, (fragTexCoord.y - 0.5)*1.5)/zoom; + c.x += offset.x; + c.y += offset.y; + float a = 0.0; + float b = 0.0; + + // The Mandelbrot set is a two-dimensional set defined in the complex plane on which the iteration of the function + // Fc(z) = z^2 + c on the complex numbers c from the plane does not diverge to infinity starting at z = 0 + // Here: z = a + bi. Iterations: z -> z^2 + c = (a + bi)^2 + (c.x + c.yi) = (a^2 - b^2 + c.x) + (2ab + c.y)i + + int iter = 0; + for (iter = 0; iter < maxIterations; ++iter) + { + float aa = a*a; + float bb = b*b; + if (aa + bb > max2) + break; + + float twoab = 2.0*a*b; + a = aa - bb + c.x; + b = twoab + c.y; + } + + if (iter >= maxIterations) + { + finalColor = vec4(0.0, 0.0, 0.0, 1.0); + } + else + { + float normR = float(iter%55)/55.0; + float normG = float(iter%69)/69.0; + float normB = float(iter%40)/40.0; + + finalColor = vec4(sin(normR*PI), sin(normG*PI), sin(normB*PI), 1.0); + } +} +`; \ No newline at end of file